Improving Rehabilitation Outcomes After Total Hip Arthroplasty
Phase: NA
Conditions: Total Hip Arthroplasty, Osteoarthritis
Sponsor: VA Office of Research and Development

 
 
 
 
 
  
Improving Rehabilitation Outcomes After Total Hip Arthroplasty 
 
NCT02920866 
 
Version Date:  11.11.2019 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Protocol #: 16-0956 
Project Title: Improving Rehabilitation Outcomes after Total Hip Arthroplasty 
 
Principal Investigator: Dr. Jennifer Stevens-Lapsley, PT, PhD 
Version Date: 11.11.2019 
 
 
  
 
 
I. HYPOTHESES AND SPECIFIC AIMS  
Over the next 20 years, the number of total hip arthroplasties (THAs) performed to alleviate pain and disability 
associated with osteoarthritis (OA) is expected to double to more than 500,000/year.1 Most patients report 
improved health-related quality of life following surgery;2-4 however, deficits in physical function and quality of 
life persist. Specifically, Veterans with THA have a higher prevalence of severe ADL limitations5 and report 
severe physical health-related quality of life deficits.6 The increased THA utilization, combined with long-term 
functional deficits which increase heath care utilization,5 suggests a need for targeted rehabilitation strategies 
to improve physical function for Veterans after THA.  
 
Movement compensations are a biomarker of functional decline in a variety of older adult populations.7,8 For 
patients with THA, persistent movement compensations are seen in activities of daily living, such as level 
walking, sit-to-stand transitions, and stair climbing.9-11 These movement compensations likely stem from a 
combination of poor muscle strength and a failure to integrate available muscle strength into functional 
movement. Functional strength integration (FSI) during daily tasks refers to the ability of the body to produce 
stable, coordinated movements.12 At the hip joint, optimal FSI is largely dependent on the ability of hip 
abductor muscles to produce sufficient hip abduction moments to stabilize the pelvis during unilateral stance 
tasks.13,14 Thus, inability to integrate hip abductor muscle strength during functional tasks results in poor pelvic 
stability and movement compensations. Lack of FSI possibly explains the deficits in functional recovery after 
THA.15 However, current rehabilitation practices do not target the integration of strength and functional 
movement to resolve movement compensations.  
 
Rehabilitation emphasizing functional strength integration after THA has the potential to substantially improve 
postoperative physical function by remediating movement compensations with greater hip abductor strength 
and recruitment during function, providing greater pelvic control and better movement quality. Therefore, we 
propose a randomized controlled trial of 100 participants to determine if an 8-week functional strength 
integration (FSI) program improves physical function and muscle performance more than control 
intervention (CON) after unilateral THA. The secondary goal is to determine if FSI improves movement 
compensations during functional activity (walking and stair climbing). Outcomes will be assessed pre-
operatively (PRE); intervention mid-point, 4 weeks (POST1); intervention end-point, 8 weeks (POST2) (primary 
endpoint); and late recovery, 26 weeks (POST3).  
 
Aim 1: To determine if FSI results in better physical function and muscle performance after unilateral THA 
compared to usual care rehabilitation. Physical function will be measured with standardized performance-
based tests [6-Minute Walk (primary outcome), Four-Meter Walk, 30 second sit-to-stand, and Functional Gait 
Assessment] and self-report measures [Western Ontario and McMaster Universities Osteoarthritis Index 
(WOMAC) and the Veterans RAND 12-Item Health Survey (VR-12)]. Muscle performance will be assessed 
with measures of muscle strength (hip abduction force) and muscle endurance (modified Trendelenburg test).  
Hypothesis 1: The FSI group will have greater physical function and muscle performance improvements than 
the CON group from baseline to POST2 (primary endpoint), and group differences will persist at POST3.  
 
Aim 2: To determine if FSI intervention more effectively reduces movement compensations than CON 
intervention after unilateral THA, as measured by peak internal hip abduction moments during gait.  
Hypothesis 2: The FSI group will have greater increases in surgical-limb peak internal hip abduction moments 
during gait compared to the CON group from baseline to POST2, and group differences will persist at POST3.  
 
Impact: Chronic movement compensation, a key biomarker of functional decline, is overlooked in current 
rehabilitation strategies following THA. The application of functional strength integration (FSI) is effective in 
remediating movement compensation for athletic populations recovering from orthopedic surgeries (e.g. 
anterior cruciate ligament reconstruction). This study will be the first to apply advanced FSI techniques in the 

rehabilitation of older Veterans with THA in order to shift the current rehabilitation paradigm and target 
persistent movement compensation and poor physical function outcomes. 
II. BACKGROUND AND SIGNIFICANCE  
Significance of the proposed study is based on: 1) the anticipated increase in utilization of total hip 
arthroplasty (THA), 2) the unknown efficacy of physical rehabilitation after THA, 3) the long-term 
strength and functional deficits after THA, 4) direct associations between movement compensations 
and physical function following THA, and 5) a novel rehabilitative approach to remediate movement 
compensations and improve functional performance.  
 
A1. Anticipated Increase in Utilization of Total Hip Arthroplasty Surgery  
Total hip arthroplasty (THA) is considered a common orthopedic procedure.16 Currently, there are over 
230,000 THAs performed each year in the United States to alleviate pain and disability associated with 
osteoarthritis (OA).17 As a result of the country’s aging population and the increasing prevalence of obesity, the 
need for THA to treat the pain and disability from hip OA is expected to increase.18 Specifically, it is projected 
that more than 500,000 THA procedures will be performed per year to relieve pain with hip OA by 2030.1  
 
A2. Efficacy of Physical Rehabilitation after THA is Unknown  
Despite evidence that strength training improves hip muscle strength and physical function, there is no 
consensus on the course of postoperative care following THA.19,20 In fact, surgeons commonly state they 
do not refer patients for rehabilitation after THA in large part because of the variability in rehabilitation 
approaches and concerns over dislocation risk. Furthermore, current rehabilitation practices have not 
addressed the common movement compensations observed before and after THA, nor evaluated their effect 
on physical function.  
 
Persistent muscle weakness, movement compensations, and physical function deficits after THA suggest 
inadequate postoperative management. It is likely that isolated strength training may not address movement 
compensations seen during activities such as walking and stair climbing after THA. The combination of 
evidence that 1) strength training improves outcomes after THA and 2) functional strength integration 
techniques improve outcomes in other patient populations12,21-27, suggests that the addition of functional 
strength integration may further improve rehabilitation outcomes following THA. Rehabilitation after THA needs 
a paradigm shift to more effectively improve movement quality and function.  
 
A3. THA Results in Long-term Strength and Function Deficits  
After THA, individuals demonstrate deficits in muscle strength, postural stability, and physical function 
compared to age-matched cohorts.28-30 Specifically, hip muscle strength is negatively impacted for several 
years after THA.30,31 Patients after THA lack 20% of the hip muscle strength of healthy adults31 and 
demonstrate 20% less strength in the surgical hip muscles compared with their non-surgical hip one year 
postoperatively. The resultant hip strength deficits are a combination of muscle weakness carryover from 
before THA32 and further declines in hip strength immediately following surgery.33 Despite experiencing 
improvements in pain following THA, full remediation of strength deficits remains an important issue in 
postoperative management. Muscle weakness is associated with poor self-reported function28, decreased 
single limb balance28, and increased fall risk.34 In fact, the odds ratio associated with weakened hip 
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Additionally, individuals experience difficulty with postural stability (i.e. balance) following THA. 
Specifically, Trudelle-Jackson et al.28 reported significant differences in postural stability in patients’ surgical 
hips one year after surgery and found correlation between self-reports of decreased function and decreased 
hip abductor strength. Further, Nallegowda et al.35 reported impairments in dynamic balance and 
compensatory balance strategies in individuals following THA compared to healthy adults. The failure to regain 
adequate postural stability during functional tasks could be related to difficulties regaining strength after THA, 
as well as an inability to integrate muscle strength into functional tasks to stabilize the pelvis and provide a 
stable base for functional movement.  
 
Full recovery of physical function is challenging after THA, as patients recover physical function to only 
80% of healthy adults.36 The difficulty with physical function in the several years following THA 

may explain why patients have lower scores on the SF-363 and are less physically active one year after THA.37 
Additionally, significant drops in SF-36 scores have been observed 5 and 7 years after surgery.3,4 Difficulty with gait 
activities such as level walking10,38 and stair climbing9 is an important and persistent problem after THA. For example, 
gait speed is nearly 20% slower than healthy older adults11 even 10 years after surgery39, and 46% of patients followed 
for 7 years after THA required an assistive device during walking, compared with only 8% of healthy older adults 
followed over the same time period3, suggesting that, after THA, patients have long-term difficulty with ambulatory 
activities of daily living. Indeed, 6-minute walk (6MW) outcomes are one of the key long-term functional limitations 
identified for people living with THA.40 The recovery of physical function may be even more challenging for Veterans 
undergoing THA. Veterans with THA have a higher prevalence of severe ADL limitations5 and report severe physical 
health-related quality of life deficits6 compared with Veterans not receiving joint arthroplasty and compared to the US 
population not receiving joint arthroplasty.5 Mobility disability (e.g. the inability to independently walk and climb 
stairs)41 places a significant financial burden on our healthcare system42 and is a risk factor for decreased life expectancy 
in older adults.41 Furthermore, mobility disability can lead to loss of independence43 and increases in fall risk34, which 
may increase hospitalization and health care utilization.43 In fact, Veterans with THA higher comorbidities and heath care 
utilization.5 The combination of the long-standing deficits present after THA, particularly in the Veteran population, 
suggests that more effective rehabilitation interventions to improve physical function and quality of life for Veterans 
after joint arthroplasty are warranted.  
 
A4. Physical Function and Movement Compensations  
Functional task performance after THA is characterized by the presence of movement compensations. 
Recently, movement compensations have been found to serve as important biomarkers of functional decline in 
a variety of older adult populations7,8 and are linked to increased fall risk7,8 and poor functional outcomes.44 
Persistent movement compensations are common after THA during activities of daily living, such as level 
walking and stair climbing. Therefore, it is not surprising that deficits in physical function after THA specifically 
relate to abnormal movement compensations. In particular, slow walking speeds observed after THA are 
related to low internal hip abduction moments, reflecting abnormal movement control at the hip and pelvis 
during gait.10,24,45,46  
 
Low internal hip abduction moments are seen prior to surgery during functional tasks and persist after THA.10,24 
Intentional integration of muscle strength training into functional movement patterns is likely needed for 
patients to break habitual movement compensation patterns and incorporate post-surgical strength gains into 
daily functional activity. For daily movement tasks, coordinated hip and pelvic muscle activity23 provides pelvic 
stability relative to the lower extremities to minimize movement compensations. Around the hip and pelvis, 
stability is largely dependent on the ability of hip abductor muscles to produce internal hip abduction 
moments to control pelvis motion during unilateral stance.13,14 In fact, the role of the hip abductor 
musculature is to adapt to perturbations experienced during function to maintain a stable pelvic base.23 For 
patients with THA, the hip abductor musculature does not adequately stabilize the pelvis, resulting in reduced 
internal hip abduction moments of the surgical hip.10,24,45 The resulting movement compensations can then 
stress other joints and create difficulty performing activities of daily living.15 Full integration of muscle 
strength requires the hip and lumbopelvic muscles to work in concert during functional task performance, thus 
providing stability around the hip and pelvis, which is not achieved solely through strength training alone. 
Further, this muscle strength integration will improve the hip abductor musculature’s ability to generate internal 
hip abduction moments to improve stability, and therefore improve recovery of physical function after THA. 
However, current rehabilitation practices have not targeted functional strength integration to address 
the resolution of movement compensations.  
 
A5. Integration of Strength and Function Improves Outcomes  
Resolving movement compensation requires exercise beyond strength training alone. Specifically, 
concentrated training to improve muscle recruitment improves movement quality and may minimize injury risk 
in numerous other patient populations.21,47 Targeted functional strength integration: 1) utilizes weight-
bearing exercises to improve muscle coordination and joint stabilization12, 2) aims to improve sensorimotor 
control and stability by emphasizing muscle co-activation, and 3) focuses on remediating movement 

compensations by emphasizing muscle recruitment and movement quality which requires functional muscle 
strength, coordination, and stability.48  
Combining strength and functional training has been used successfully in rehabilitation for other chronic injury 
populations—specifically, after anterior cruciate ligament (ACL) reconstruction and for patients following ankle 
sprain.21,27,49,50 Emphasizing proper muscle recruitment, stability, and strengthening for improved stability 
during functional tasks effectively improves gait mechanics27, increases hip abductor strength21, increases joint 
stability50, and prevents further injury.49 Additionally, this type of integrated training has been utilized 
successfully in older adults with hip and knee OA, but not after THA.12 The addition of this type of training to a 
postoperative THA rehabilitation protocol has the potential to not only resolve persistent movement 
compensations following THA, but also to change the rehabilitation approach for patients after THA.  
 
In summary, full recovery of physical function after THA entails both strength training and remediation of 
movement compensations through improved integration of strength and function, thus improving recovery and 
physical functioning after surgery. Because no evidence-based recommendations exist to guide exercise 
prescription after THA, this study will add significant knowledge for postoperative rehabilitation guidelines and 
thereby has high potential to change clinical practice for Veterans undergoing THA.  
 
The proposed study is innovative in that it will: 1) uniquely target movement compensations to 
promote pelvic stability for improved physical function, 2) shift clinical practice evidence regarding 
postoperative rehabilitation, and 3) challenge current convention that rehabilitation is not necessary 
after THA.  
 
B1. Unique Approach to Target Movement Compensations  
The proposed RCT uses a unique rehabilitation paradigm following THA to target movement compensation. 
Our pilot feasibility study used instrumented motion analysis to quantify movement compensations after THA 
by focusing on the internal hip abduction moments that control the pelvis during functional tasks. In the pilot 
study, we demonstrated that targeted functional strength integration substantially attenuated movement 
compensations through improved surgical limb internal hip abduction moments during walking and stair 
stepping tasks. The proposed RCT will build upon the results of our pilot feasibility study and be the first trial 
to specifically target remediation of physical function and muscle performance to alleviate movement 
compensations and improve hip abduction moments during gait. The intervention strategy for the pilot 
feasibility study included a targeted functional strength integration (FSI) program, designed to address 
movement compensations and impaired surgical limb internal hip abduction moments present during single-
limb support tasks such as walking. Zeni and colleagues51 have recently shown that patients with unilateral hip 
OA have lower internal hip abduction moments during gait on the affected limb compared to the unaffected 
limb before surgery. Consistent with existing literature46,51, our pilot data confirm the presence of impaired 
internal hip abduction moments on the surgical limb before surgery and also demonstrate that without targeted 
intervention, surgical-limb hip abduction moments worsen after surgery (see section D1.4). Other studies have 
also shown that peak internal hip abduction moments are impaired after THA during walking and stair 
climbing.45,52 Identification of the peak internal hip abduction moment as a specific metric to quantify movement 
compensations is critical for assessing targeted rehabilitation strategies. This proposed study is the first to 
provide a specific intervention to target resolution of movement compensations and provide peak internal hip 
abduction moment as a specific metric for quantifying improved movement patterns.  
 
B2. Shift in Clinical Practice Patterns  
Shifts in rehabilitation strategy have occurred in other patient populations, but not for THA. For example, 
following a lateral ankle sprain injury, once considered a relatively minor injury, individuals often suffer from 
chronic joint instability.27 After identifying that individuals suffered from chronic functional mobility limitations, 
pain, and instability, rehabilitation professionals began incorporating balance, neuromuscular re-education, and 
sensorimotor training techniques to improve outcomes for individuals after ankle sprain, similar to the proposed 
FSI protocol. Recent publications indicate that these training techniques have improved ankle strength and 
postural stability25,27, improved ankle movement during gait26, and reduced the risk of reinjury.24 Rehabilitation 
following injury in the knee has had a similar evolution. In addition to more aggressive mobilization and 
strength training following ACL surgery, functional neuromuscular re-education techniques, similar to the 
proposed FSI protocol, have been used successfully to improve strength21,48, to improve movement strategies, 
and to reduce risk of ACL injury in at-risk populations.49 The application of similar rehabilitation strategies to a 

post-THA rehabilitation protocol should have a similar positive impact on future rehabilitation standards of 
practice.  
 
B3. Challenge Current Postoperative Convention  
Current practice patterns following THA do not routinely include rehabilitation. After an inpatient hospital stay, 
including rehabilitation strategies to prepare patients to go home, home-based physical therapy is occasionally 
utilized, and outpatient more rarely. Recent communication with 6 local hospitals in the Denver area indicates 
that none routinely refer their patients to outpatient rehabilitation due to lack of evidence establishing the 
benefits of, and guidelines for, rehabilitation. Only 2 of the 6 hospital facilities recommend 1-2 weeks of home 
physical therapy (2x/wk). Although not well documented in the literature, conversations with rehabilitation 
specialists and orthopaedic surgeons suggest a common misperception that early, intensive intervention may 
increase musculoskeletal injury (e.g. specifically hip dislocation risk). These conversations further suggest that 
healthcare professionals desire evidence of safe and effective rehabilitation approaches for THA patients.  
Although no consensus exists for managing patients after THA, emerging literature supports the benefits of 
physical rehabilitation after surgery. In a systematic review of rehabilitation strategies following THA, DiMonaco 
and Castiglioni concluded that rehabilitation can improve muscle strength and functional performance 
outcomes following THA.53 However, variable approaches to types of exercise, timing of rehabilitation 
initiation, and exercise intensity led to a lack of agreement on the optimal rehabilitation prescription following 
THA. A second review article by Minns-Lowe et al. also identified benefits of rehabilitation after THA, but 
emphasized that study quality and intervention improvements are needed.54 Preliminary studies have 
provided evidence that progressive, high intensity strength training early after THA may be safe and effective 
for improving strength and physical function.22,55-58 However, studies have not emphasized functional 
strength integration as a central component of a rehabilitation program to address movement 
compensations that affect functional performance. The successful implementation of our proposed FSI 
program will explore whether such an emphasis more effectively remediates functional performance deficits 
after THA than previous rehabilitation strategies. Furthermore, improved outcomes will challenge the 
perception that rehabilitation is not necessary or increases injury after THA surgery.  
 
III. PRELIMINARY STUDIES  
A1. Preliminary Studies  
Dr. Jennifer Stevens-Lapsley (PI) has led the design, implementation, and publication of several clinical 
research studies involving patients with total joint arthroplasty59-66, including 2 recently completed randomized 
controlled trials (NIH R03AR054538 and K23AG029978)66,67 and one large-scale RCT in the final stages of 
completion (R01HD065900). These clinical trials involved acute (48 hrs), subacute (1-6 months), and long term 
(12-24 months) measures of muscle strength and function and successful implementation of postoperative, 
multi-site rehabilitation programs. The PI and investigative team have also recently completed two 
investigations to 1) characterize physical recovery after THA and 2) provide initial data on the efficacy of 
rehabilitation focused on functional strength integration after THA as currently proposed.  
 
A1.1. Outcomes Following Total Hip Arthroplasty  
In a previous longitudinal, observational study,33 the investigative team concluded that patients experience 
early postoperative strength losses and decreased functional capacity after posterolateral THA, and these 
deficits persist. Specifically, one month after THA, patients had 15% less hip flexor and extensor torque, 26% 
less abductor torque, 14% less knee extensor and flexor torque, and worse performance on the stair climbing, 
timed-up-and-go (TUG), and 6-minute walk (6MW) compared to preoperative values. Twelve months after 
THA, patients had 17% less knee extensor torque, 23% less knee flexor torque, and performed approximately 
10-15% worse on measures of physical function (e.g. stair climbing, TUG, and 6MW), than healthy peers. SF-
36 Physical Component Scores, although significantly improved from preoperative levels, were significantly 
worse than healthy adults 1 year after THA (p < 0.01). These results demonstrate that strength and 
physical function deficits do persist after THA, and indicate that rehabilitation might address these 
deficits, especially in the first month after surgery when deficits are greatest.  
 
A1.2. Functional Strength Integration after Total Hip Arthroplasty: A Pilot Study  
A second study conducted by the investigative team was designed as the feasibility and initial efficacy study for 
the current proposal. In this pilot THA rehabilitation study, a multi-component intervention with specific focus on 
integrating strength and function as currently proposed (i.e. FSI; see D2.2) was compared to control group 

outcomes. The control group participated in supervised 
home-based recovery following surgery. Study staff 
visited patients at home once per week in the early 
postoperative period and continued to follow patients by 
telephone and home visits in the later postoperative 
period. Control group participants continued prescribed 
exercises from their hospital stay throughout the study 
intervention phase, with advice to progress as tolerated. 
Further, study staff advised patients in assistive device 
use, functional mobility around the house, and 
encouraged participation in activities of daily living as 
tolerated. Results of the pilot study (n=20) suggest strong 
potential for functional strength integration (FSI) to 
improve functional outcomes. Specifically, at the end of 
intervention, the FSI group had significantly greater 
improvements in SCT (P=0.030), 4MW (P=0.001), and 
6MW (P=0.002) compared to controls (Figure 1). At 10 
weeks after THA, there was a trend for the FSI group to 
remain more stable at the pelvis during static single limb 
support (p=0.070) and have greater hip abductor strength improvement (P=0.090). Further, the FSI group had 
significantly greater improvements in self-reported function in the HOOS ADL (P=0.010), Pain (P=0.009) and 
QOL (P=0.040) subscales. This investigation provides strong initial evidence that physical function can 
be improved through FSI intervention, but a larger scale intervention is necessary to more definitively 
demonstrate benefits of FSI intervention. 
A1.3. Anterior Surgical Approach THA 
Patients in the two aforementioned preliminary studies received a posterolateral THA. Because of increasing 
interest in a direct anterior surgical approach for THA68, we investigated functional outcomes and response to 
FSI intervention in a cohort of individuals undergoing THA surgery using an anterior approach. The results of 
this sub-study indicate that individuals undergoing a direct anterior approach THA had similar outcomes 
postoperatively and responded similarly to the FSI rehabilitation program as patients undergoing 
posterolateral approach THA. Specifically, there were no significant differences in early postoperative 
outcomes (2 weeks) for 4MW speed or TUG times between the posterolateral and anterior approach groups. 
Additionally, the anterior cohort had similar trajectory of functional recovery as the FSI posterolateral group, 
with no group differences in SCT, 6MW, or 4MW at the conclusion of the intervention period. There is currently 
a paucity of prospective data; those that do exist are conflicting with some finding differences in functional 
outcomes68-70 and others finding no differences in functional outcomes between surgical approaches.71-75 With 
conflicting evidence, no definitive conclusions can be drawn as to the effect of surgical approach on functional 
recovery. It is clear that hip abductor performance and pelvic stability are impaired prior to surgery51, and 
therefore, regardless of surgical approach, need to be addressed with postoperative rehabilitation. Because of 
increasing utilization of the direct anterior approach, randomization for the proposed investigation will include 
stratification by surgical approach (posterolateral or direct anterior approach THA). Including patients with both 
surgical approaches will increase the generalizability of study findings to more substantially impact clinical 
practice. 
A1.4. Movement Compensations are Sensitive to Targeted Rehabilitation 
We examined movement compensations in a subset of patients from the pilot study (D.1.2) using 3-D motion 
analysis, with specific analysis of hip joint moments (n=15). The pilot study analysis revealed that movement 
compensations can be identified in the functional hip joint mechanics after THA and that these measures are 
sensitive to change with FSI intervention. Specifically, the control group had reduced surgical limb internal hip 
abduction moments after surgery (Figure 2). However, the FSI intervention group had increased surgical-limb 
peak hip abduction moments after intervention, during both level ground walking and stair stepping. 
Specifically, in our small cohort of 15 patients (5 control and 10 intervention) we found a minimal increase (0.02 
Nm/kg) in internal hip abduction moment during walking from before surgery to 10 weeks after surgery in the 
FSI intervention group and a decrease (-0.20 Nm/kg) in the control group. The changes seen in the surgical 

limb peak internal hip abduction moments resulted in 
greater asymmetry in movement patterns at the 10-week 
time point for the control group than for the FSI 
intervention group. This can be seen when looking at the 
internal hip abduction moments across the gait cycle for both 
the surgical and non-surgical limbs (Figure 3), resulting in less 
gait compensation for the FSI intervention group. It is possible 
that the improvement in gait compensation is directly linked to 
the observed improvement in functional outcomes seen in the 
FSI intervention group (Section D.1.2). The proposed study 
aims to specifically answer the question of how targeted 
FSI can affect both gait compensation and functional 
outcomes after THA.
IV. RESEARCH METHODS 
A1.1. Patients 
One hundred-fifty patients aged 50-85 years with hip OA, 
scheduled for a unilateral, primary THA will be enrolled, with at 
least 80 patients expected to complete the study. Patients will 
have a THA performed by surgeons who will refer patients who 
meet the following criteria: 1) no severe contralateral leg OA (< 
5/10 pain with stair climbing) nor other unstable orthopaedic 
conditions that limit function, 2) no neurological or pulmonary 
problems that severely limit function, 3) no uncontrolled 
hypertension oUGLDEHWHVDQGERG\PDVVLQGH[NJP
(for motion capture reliability). Referring surgeons will perform 
THA using their preferred surgical approach (anterior or 
posterolateral). Upon referral and prior to surgery (PRE), 
eligible patients will visit the GRECC Human Movement 
Analysis Lab for informed consent and baseline 
measurements. Two weeks after surgery, with physician 
approval, they will be randomization into 1 of 2 treatment 
arms: FSI (experimental) group or CON (control) group. The 
randomization process and maintenance of treatment code 
records will be managed by Jeri Forster, PhD (biostatistician),
who will not be involved in patient testing/treatment. This will 
maintain the double-blinded condition for 
participants/researchers collecting data.  
A1.2. Rehabilitation 
Following THA surgery, standardized inpatient rehabilitation programs will be implemented for all patients 
(Figure 4). Upon returning home, patients in both groups will receive a phone call and/or home visits (if 
necessary) from a study physical therapist from our research team to ensure safety, provide ADL training, and 
monitor for complications. Randomization and initiation of study treatment will follow this 2-week recovery
period to allow for early recovery before intervention. Following randomization, both groups will participate in 
an 8-week outpatient rehabilitation program (~40 minutes per session) at the outpatient PT Clinic, or at the 
Phone 
call/home 
visits

participant’s home.  PTs will use full PPE (gloves, mask, and face shield): 2x/week for 6 weeks and 1x/week 
for the last 2 weeks. Both groups will also have a home exercise program. The FSI group will receive specific 
exercises focusing on integration of strength and function to optimize femoropelvic alignment and pelvic 
stability. The CON group will mimic typical postoperative care focused on ADL training and range of motion 
(ROM) (see details below & appendix).  
Functional Strength Integration Group Rehabilitation Program  
The FSI program will target the integration of strength gains into lumbopelvic stability and movement quality 
during daily living, thus optimizing physical function for Veterans after THA. The exercise program consists of 
rehabilitation techniques to address the well-established, long-term impairments of muscle weakness and 
functional movement compensations after THA.11,30,39 Specifically, the FSI intervention involves strengthening 
for the hip musculature similar to previously published protocols22,56, combined with focused techniques 
emphasizing early initiation of hip muscle recruitment to stabilize the pelvis, thus integrating strength and 
movement pattern training to maximize functional recovery. The FSI program includes therapeutic exercise in 3 
domains: pelvic stability (PST) training, functional training (FT), and strength training (ST) (Table 1). 
Activities in the PST domain include early surgical-limb weight bearing activities and core muscle strengthening 
exercises designed to progressively increase in difficulty based on patient performance benchmarks and 
therapist monitoring. Activities in the FT domain focus on gait and stair climb exercise, which progresses to 
higher level agility training. The ST domain includes progressive, resistance exercise to remediate strength in 
the lower extremities in the major muscle groups impacted by THA.33 The ST exercises will include use of 
weighted pulleys and weight-training machines. Therapists will determine an 8-repetition maximum for each 
muscle group and weight will be increased by at least 10% every 2 weeks to maximize muscle hypertrophy 
and strength gains. The novelty of the FSI program lies in the focus on integrating strength and function 
through progressive functional exercises promoting muscle coordination around the hip, thus optimizing 
alignment between femur, pelvis and lumbar segments.13  
 
Control Group Rehabilitation Program  
There is no standard of care for rehabilitation following THA.53 Observed practice patterns from previous 
investigations33 and discussion with physical therapists indicate that patients receive rehabilitation services 
during the 2-3 day hospital stay after THA, but not routinely after hospital discharge. Yet, to control for attention 
and volume of rehabilitation for the FSI group, patients in the control group will attend outpatient physical 
therapy for 14 visits (40 minute sessions) over 8 weeks. This control program will mimic the typical 
postoperative experience for patients in our community, in which patients independently manage their activity. 
This program will focus on patient education, functional ADL training, and therapeutic exercise. However, the 
activities in the exercise domain will be limited to low load exercise such as isometric muscle exercise, ROM, 
and flexibility activities. These activities are specifically designed to mirror usual care activity. These activities 
will not include progressive strength training exercise or specific functional activity to improve pelvic stability 
and core muscle strength, which are exclusive to the FSI group.  
 
A1.3. Data Collection and Outcome Measures  
Baseline testing will occur 2 weeks prior to THA. To develop a more precise estimate of the trajectory of 
recovery after THA, we will assess outcomes at 3 times postoperatively. Postoperative testing will occur at 
intervention mid-point, 4 weeks (POST1); intervention end-point, 8 weeks (POST2) (primary endpoint); and 
late recovery, 26 weeks (POST3). The 4-week test will allow for identifying if any changes occur early in the 
intervention, the 8-week test will serve as the primary endpoint for assessing intervention efficacy, and the 26-
week test is important to assess persistence of intervention effects. Testing will be performed using 
standardized procedures described below.  Testing may occur remotely via Zoom or video call, at the 
participant’s home, or on the Anschutz campus. 
 
 

 
Abbreviations: PST= Pelvic Stability Training; FT= Functional Training; ST= Strength Training; PED: Patient 
Education,   TE= Therapeutic Exercise, AD= Assistive Device.  
*FSI group activities in each domain will be supervised closely with verbal, visual, and tactile cues to promote 
optimal posture and movement quality. Progression of activities in the PST and FT domains will be based 
on therapist assessment of movement quality, specifically the absence form fatigue, and the ability to maintain 
a level pelvis with hip muscle activation during the task. Therapists will progress strengthening exercises 
when patients are able to demonstrate proper form during the prescribed 8 repetitions (e.g. 80% of 1 repetition 
maximum). Therapists will be encouraged to push patients to work at a high level of difficulty and progress 
toward Phase 3 as quickly as possible.  
** CON group activities are progressed based on the post-operative timeline indicated above (by phase and week)   
 
 
Phase 
Functional Strength Integration Program (FSI) * 
Control Group Program (CON)** 
Phase 1 
Weeks 
1-2 
PST: Standing weight shifting and supported 
single leg balance; isometric abdominal training 
supine; see progression criteria below* 
FT: Gait training, review postop precautions; see 
progression criteria below* 
ST: Lower extremity progressive resistance 
exercise (2 sets x 8 reps at 8RM); see 
progression criteria below* 
PED: Review postsurgical precautions, ADL advice  
FT: Gait training with AD 
TE: Muscle setting exercise for hip and knee 
(continue from inpatient therapy), P/AAROM for all hip 
motions 
Phase 2 
Weeks 
3-5 
PST: Foam surface weight shifting, unsupported 
single leg balance, standing pelvic lift; resisted 
abdominal stabilization training (supine)* 
FT: Gait training with no AD, sit-stand activity, 
small step-up forward and lateral; ST: Progress 
lower extremity resistive exercise by at least 10% 
(2sets x 8 reps)* 
PED: Continue education on postsurgical 
precautions, AD utilization and ADL advice 
FT: Gait training with AD 
TE: AA/AROM for all hip motions, low load supine 
resistive exercise; flexibility activity for spine and 
lower extremity.  
Phase 3 
Weeks 
6-8 
PST: Foam surface single leg balance and pelvic 
lift, balance board, progress to BOSU ball for all 
activity; supine bridging, upper abdominal curl, 
hundreds (Pilates), side lying series (Pilates).* 
FT: Moderate Æ high step ups forward, lateral, 
down. Agility training, wall squats.* 
ST: Progress lower extremity progressive resistive 
exercise by at least 10% (2 sets x 8 reps).* 
PED: AD progression, ADL advice on safe activity 
resumption 
FT: Gait training with/without AD as indicated 
TE: AROM all hip motions, supine resistive exercise, 
stretching, and flexibility activity for spine and lower 
extremity. 

A1.3.1. Performance-based Physical Function Measures  
Performance-based measures of physical function with well-established reliability and validity will include the 6-
minute walk test (6MW) (primary outcome), 4 meter walk test (4MW), 30 second sit-to-stand test, and the 
Functional Gait Assessment (FGA) (Table 2). Patients will also perform a 6MW test76, which assesses how far 
a patient walks in 6 minutes. The 6MW test was chosen as the primary outcome because it captures 
performance over a period of time that best mimics community ambulation with activities of daily living. The 
6MW test is reliable and valid in the post-THA population and can detect small changes in function after THA.77 
The 4MW test measures the time to walk 4 meters and has been used to generate gait speed values, which 
have been associated with morbidity and mortality in older adults.78 Participants will perform the 4MW with 
instructions to walk in their “normal, everyday pace.” The 30 second sit-to-stand test assesses functional lower 
extremity strength and endurance, and has been validated and found reliable in older adults at various physical 
activity levels and physical independence levels.79-81 Participants will also perform the FGA, which is a 10-item 
objective outcome measure designed to measure dynamic balance while walking in the presence of external 
demands, and will provide information on patients’ stability before and after THA.82 The FGA has been shown 
to be a reliable and valid measure, effective in classifying fall risk in older adults and predicting unexplained 
falls.82,83  
A1.3.2. Self-reported Outcomes  
Patients will complete the Veterans RAND 12-item health survey (VR-12), the Western Ontario and McMaster 
Universities Osteoarthritis Index (WOMAC), and a motivation scale at each visit. The Patient Activation 
Measure (PAM) survey will be administered only at the baseline visit. The VR-12 is a reliable, self-report 
survey for assessing health-related quality of life.84-86 The WOMAC assesses the impact of osteoarthritis on 
pain, stiffness, and disability.87 The WOMAC has been shown to be a valid, reliable, and responsive instrument 
often used in clinical trials.87 The PAM survey assesses patient knowledge, skill, and confidence for self-
management, as self-efficacy exhibits a positive relationship with preventive actions and health outcomes.88,89 
The motivation scales asks the participant “How motivated do you feel to participate in physical therapy?”, and 
rating on a 0 (not at all motivated) to 10 (very motivated) scale. 
 
A1.3.3. Muscle Performance Measures  
Isometric strength of the quadriceps and hip abductor muscles will be assessed on a handheld dynamometer. 
All strength testing will be performed in positions that minimize the risk of hip dislocation post-operatively, while 
still allowing for optimal trunk and pelvic stabilization. Isometric quadriceps strength testing will be performed in 
sitting at 0° hip flexion and 60° knee flexion. Isometric hip abduction strength testing will be performed in side 
lying at 0° flexion/extension and 0° hip abduction.33 Testing will include warm-up repetitions, followed by three 
separate maximal voluntary isometric contractions while receiving visual and verbal feedback. Additionally, 
patients will complete hip abductor endurance testing using a static single-limb balance test, based off of the 
Trendelenburg test proposed by Hardcastle14 and measurement of pelvis angle by Youdas, et al.90 and 
Asayma et al.91 This modified Trendelenburg test14 assesses neuromuscular control during timed, single limb 
stance and indicates the ability of the lateral hip muscles to maintain pelvic control during closed-chain, 
functional tasks and therefore serves as a measure of hip abductor muscle endurance.14 This test will be 
performed in the GRECC Human Movement Analysis Lab using a high-speed motion-capture system to 
assess lateral pelvic tilt (see D2.3.1). Differences will be analyzed in pelvic tilt angles from preoperative to 
postoperative assessments during the single-limb task on the surgical leg. 
A1.3.4. ActiGraph Physical Activity Monitoring  
ActiGraph physical activity monitors (ActiGraph Inc. Pensacola FL) will be used to obtain an objective measure 
of physical activity (PA). ActiGraph activity monitors assess PA using accelerometry, which allows objective 
evaluation of the relative volume (steps/day) and intensity (activity counts) of physical activity with high validity 
and reliability.92-94 Each participant will wear the ActiGraph for at least 4 days at all time points to assess 
average daily PA (steps/day).95,96 The ActiGraph monitor will be used only for outcome data (not intervention) 
and provides no feedback to participants. 
 
 

 
 
A1.3.5. Biomechanical Analysis and Measures of Pelvic Stability  
Lower extremity biomechanical measures will be used to quantify movement patterns during level walking and 
stepping up/down from an 8” stair step in the GRECC Human Movement Analysis Lab. Similar protocols for the 
assessment of movement patterns have been performed in the pilot studies leading to the current proposal and 
other previous work on movement patterns for patients with hip OA and THA.24,45,51,52 Surgical limb peak 
internal hip abduction moment, will be calculated with 3-D instrumented motion analysis. Briefly, lower 
extremity joint kinematics will be quantified from wearable sensors and retro-reflective markers tracked via an 
8-camera, high speed motion capture system (Vicon Motion Systems, Oxford, UK) at 100 Hz. Lower extremity 
joint kinetics will be derived from ground reaction force data recorded from two force platforms (2000 Hz) 
embedded in the floor that are synchronized with the cameras (Bertec, Columbus, OH). Continuous internal hip 
abduction moments will be calculated during functional task performance using a standard inverse dynamics 
approach integrating kinematic and kinetic data using Visual 3D software (C-Motion, Germantown, MD). From 
the continuous hip moments, peak surgical limb internal hip abduction moments during the Loading Response 
phase of the stance period of the walking trials will be collected. All joint moments will be normalized to 
participant body mass. Dr. Cory Christiansen (co-investigator) will oversee all aspects of the biomechanical 
analysis.  
 
A1.3.6. Safety Outcomes  
Patients will report falls, musculoskeletal injury history, and pain levels at rest and with activity (numerical pain 
rating scale [NPRS; 0= no pain, 10= worst possible pain]) on a weekly basis during the intervention and 
biweekly via phone calls through 26 weeks. Additionally, treating physical therapists will monitor incidence of 
musculoskeletal injury (specifically, hip dislocation) by completing a brief examination at each treatment 
session. Finally, surgical success will be evaluated by incidence of neurologic palsy, infection, deep vein 
thrombosis/pulmonary embolism, skin necrosis, delayed wound healing, vascular injury, and surgical revision.  
 
A1.4. Procedural Reliability  
Procedural reliability is critical to the success of the proposed intervention. We have established mechanisms 
to assure consistency of treatments across sites consistent with previous reports of procedural oversight and 
treatment fidelity.97 Participating Veterans will attend outpatient PT visits at one of the following locations- 
Denver VAMC (9th Ave. clinic), AMC PT program clinic, PFC Floyd K. Lindstrom Outpatient Clinic at Colorado 
Springs, or Golden Outpatient Clinic with structured oversight seen to by the investigative team. Dana Judd, 
PT, PhD (co-investigator) will oversee the standardization and implementation of the rehabilitation programs at 
the clinical site. The PI will oversee the methodological issues related to fidelity of treatment across treating 
therapists and address any clinical trials issues specific to rehabilitation. She will meet regularly with Dr. Judd 
to troubleshoot any difficulties that arise and provide additional oversight to ensure the fidelity of the 
investigation.  
 
Outcome Measures 
Baseline 
POST1 
POST2 
POST3 
Physical Function: 6MW 
X 
X 
X* 
X 
Physical Function 4MW, 30 sec Sit-to-Stand, FGA 
X 
X 
X 
X 
Muscle Strength: Quadriceps and Hip abductor strength, 
Trendelenburg 
X 
X 
X 
X 
Peak internal hip abduction moment 
X 
X 
X 
X 
ActiGraph Physical Activity Monitors 
X 
X 
X 
X 
Self-report: VR-12, WOMAC, PAM survey (baseline only), Motivation 
scale (POST1  and POST2  only) 
X 
X 
X 
X 
Safety Outcomes: Falls, injury, pain 
 
X 
X 
X 
*Primary end-point and outcome measure 
Table 2 Timetable of Outcome Measures 

There will be 2 therapists to treat study patients (1 FSI and 1 CON) at each PT clinic. This will minimize the 
potential for contamination, as each therapist will be unfamiliar with the specifics in the other program. 
Furthermore, patients by group will be scheduled for morning vs. afternoon treatments to minimize patient 
contamination. Dr. Judd and the PI will provide 3 initial training sessions to review treatment protocols and 
documentation. FSI-trained therapists will receive instruction on providing visual, verbal, and tactile feedback 
during FSI activities, as well as instructions on monitoring pelvic position to maximize muscle recruitment and 
movement quality and how to determine form fatigue. This specific training will ensure successful 
implementation of the FSI program and ensure therapists are providing the same feedback to patients during 
exercise and using the same criteria to dose exercise. CON-trained therapists will receive instruction on topics 
to be included for patient education, specific activities to include in the clinic and home exercise programs, and 
proper dosages for each activity. A manual will be provided to the clinic with protocol details for each group 
(FSI and CON), clinic and home exercises, and documentation forms. Separate manuals for each program will 
be produced, and therapists will be instructed not to share intervention details with other therapists. In addition, 
every month for the first year, and every 3 months thereafter, treating therapists from the clinical site will meet 
with Dr. Judd to discuss treatment guidelines and any issues that have surfaced. Dr. Judd will monitor patient 
treatments weekly for the first 2 patients in each treatment group. Should new therapists be added to the 
treatment team during the course of the proposed investigation, the same procedures for initial 
training/monitoring will be implemented. For each clinical site, a procedural reliability checklist (Appendix) for 
adherence to the rehabilitation protocol across therapists will be completed weekly for each of the first 2 
patients in each treatment group. For the remaining patients, procedural reliability will be evaluated at the 
midpoint and end of treatment. If the procedural reliability is below 90%, additional training sessions will be 
scheduled with individual therapists. Procedural reliability using this approach for our existing studies with 
patients following knee and hip arthroplasty (n=192 patients) at similar clinical sites has been 96.6%. 
Therefore, based on our extensive experience with this approach with procedural reliability in similar trials (NIH 
R01-HD065900, R03-AR054538, K23-AG029978), we expect the procedural reliability to be greater than 90% 
for all observations.  
A1.5. Data Management  
Study data will be collected and managed using the REDCap (Research Electronic Data Capture) platform. 
REDCap is a secure, web-based application designed to support electronic data capture for research studies, 
providing user-friendly case report forms, real-time data entry validation (e.g. for data types and range checks), 
audit trails, transaction logs, and a de-identified data export mechanism to common statistical packages. Data 
will be placed on the REDCap Instance at the Colorado Clinical and Translational Sciences Institute (CCTSI). 
This data will be used solely for the purposes defined for this specific study. Data placed on the CCTSI 
REDCap Instance will not be accessed or used for any other study or purpose, and will only be accessed by 
VA-credentialed personnel. The CCTSI REDCap Instance is a highly secure, nationally-utilized data 
management system, and it is housed within the highly-secure environment at the University of Colorado. 
A1.6. Data Analysis  
The primary outcome for this study is change in 6MW distance from baseline to POST2 (end of study 
intervention). Secondary physical function and muscle performance outcome measures include change in 
4MW, 30 sec sit-to-stand, isometric hip abductor strength, and hip abductor muscle endurance. Secondary 
self-report outcome measures include the WOMAC and VR-12. Measures of movement compensation after 
unilateral THA include peak internal hip abduction moments during walking from baseline to POST2. 
Preliminary descriptive and graphical analyses (e.g. boxplots, scatterplots, and profile plots over time) will be 
used for data checking and visualization. All analyses will assume a two-sided test of hypothesis, with a 
significance level of 0.05, and be performed in SAS v9.4 or higher and R v3.2.2 or higher.  
 
Primary Analysis: The primary analysis will be an intent-to-treat comparison between groups of the change in 
6MW distance from baseline to POST2 (end of intervention). Statistical inference regarding the difference 
between treatment groups will be based on the estimated coefficient for a group indicator variable in an 
analysis of covariance (ANCOVA) model with the change from baseline at POST2 for the 6MW distance being 
the response variable. Additional covariates will include the stratification variables (surgical approach and 
Veteran/non Veteran) and the baseline value of the 6MW distance to improve the precision of the estimate. 

The conclusion about differences between treatment groups will be determined by this single statistical test to 
protect against an elevated risk of false positive conclusions. A similar analysis will be performed on the 
change from baseline to POST3 to determine persistence of group differences to 26 weeks. Additionally, a 
sensitivity analysis will be performed utilizing a mixed-effects model and all available data, with estimation of 
the change from baseline to POST2 and POST3. If the sensitivity analysis is not consistent with the primary 
analysis, the results will be considered inconclusive.  
 
Secondary Analyses: Differences between groups in the secondary outcomes for physical function, muscle 
strength and endurance, and peak internal hip abduction moment, from baseline to POST2 will also be 
analyzed as described above. All outcomes will be analyzed at POST3 to evaluate the long-term impact and 
sustainability of the FSI training. We anticipate that secondary outcomes will be correlated with the primary 
outcome, so that similar effects on secondary outcomes will reinforce significant differences in the primary 
outcome. Failure to observe consistency between primary and secondary outcomes will be taken as evidence 
that the effects of FSI intervention are not clear, and that further study is necessary to resolve inconsistencies. 
This approach reduces the risk of false-positive conclusions resulting from multiple statistical tests.  
A1.7. Sample Size Estimates  
Statistical power was estimated using variability estimates from Heiberg et al. (2015), where the change in 
6MW distance was assessed for 60 participants following THA.98 Because Heiberg’s target population was 
comparable to that currently proposed, and their sample size was 3 times that of our pilot study, our estimates 
using these data98 are expected to serve as the best estimate of samples size. As such, the observed SD at 3 
months post-surgery for the sample was 81.3. Based on this SD, a 2-sample, 2-sided t-test at the 5% level with 
80 patients (40 per group) would have 90% power to detect a clinically meaningful difference of at least 59.7 
meters.99 The primary analysis using linear regression will be conditioned on the baseline value of each 
outcome measure, in addition to the sex and surgical approach stratification variables, thus improving the 
precision of (and giving greater power to) the estimates. We will recruit 150 participants (75/group) to allow for 
loss to follow-up.  
 
A1.8. Alternative Approaches and Limitations  
Missing Data. All participants with outcome measurements will be included in the intent-to-treat analysis. 
Although we will encourage participants to be fully compliant to their assigned treatment regimen and testing 
sessions, they will not be dropped from follow-up measurements for lack of compliance. The importance of 
complete follow-up will be stressed during enrollment and consent, and repeated during study participation. 
Participants will be contacted repeatedly if they miss follow-up visits, and all efforts will be made to get 
participants to return for scheduled follow-up visits. Although statistical methods can be used to “adjust” for 
missing data, these methods rely on the untestable assumption that data are “missing at random” so that the 
effect of the missingness can be removed through statistical modeling. We will instead focus on preventing 
missed follow-up visits.  
Differences in surgical approach. There remains a paucity of prospective data comparing physical function 
outcomes with posterolateral versus direct anterior THA surgical approaches. Therefore, including both 
surgical approaches (and stratifying by approach) will increase the generalizability of the study. Furthermore, 
this strategy may also provide additional insights regarding any potential differences in surgical approaches. 
Finally, we have intentionally chosen not to include less common, alternative THA surgical approaches (e.g. 
direct lateral) to focus stratification on the most commonly used THA surgical approaches.  
A1.9. Timeline  
Anticipated project timeline and cumulative enrollment. Local IRB approvals will be finalized prior to 
initiating the investigation. Study enrollment will start in months 3-4 and continue through the first part of year 
4, with a targeted accrual rate of 2-3 patients/month. Abstract and manuscript preparation will begin in years 2-
3, but will increase in year 4. 
A1.10. Future Investigation  
1) Evaluate strategies for dissemination and implementation of study findings in clinical practice.  
While the proposed FSI intervention is novel, it has been designed for practical implementation in clinical 
settings to facilitate more rapid dissemination of study findings into routine clinical practice. We will explore 
strategies to optimize such dissemination and implementation.  

2) Determine the optimal length of FSI intervention.  
If FSI results in faster and more extensive recovery after THA, future investigations could explore whether 
shorter FSI intervention would achieve the same results to minimize atypical movement patterns and decrease 
rehabilitation costs.  
3) Examine the long-term effects of FSI intervention.  
If FSI results in improved recovery and movement quality, the long-term effects of these improvements should 
be investigated. We plan to seek additional opportunities to follow this cohort to collect data on musculoskeletal 
health indicated by prevalence of: additional orthopedic pain or injury, health care utilization related to 
musculoskeletal health, and subsequent osteoarthritis diagnoses and joint replacement surgeries in each 
group. 
 
Task 
Year 1 
Total 
Year 2 
Total 
Year 3 
Total 
Year 4 
Total 
Training of personnel 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Screening & enrollment 
 
 
 
 
25 
 
 
 
 
50 
 
 
 
 
75 
 
 
 
 
100 
Data collection 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Data entry & analysis 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Abstract/manuscript prep 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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