Metabolic Cost and Physical Activity in Sedentary Adults With a Unilateral Transtibial Amputation as Compared to Controls
Conditions: Amputees
Sponsor: University of Delaware

Cover Page 
 
 
TITLE:  Metabolic Cost and Physical Activity in Sedentary Adults with a Unilateral Transtibial Amputation as 
Compared to Controls 
NCT Number: Not Yet Assigned 
 
Date of Document: 04/19/2018 
 

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HUMAN SUBJECTS PROTOCOL  
University of Delaware 
 
Protocol Title: Metabolic Cost and Physical Activity in Sedentary Adults with a Unilateral 
Transtibial Amputation as Compared to Controls  
 
 
  
 
Principal Investigator   
 
 
Name: J. Megan Sions, PhD, DPT, PT 
 
Department/Center: Physical Therapy 
 
Contact Phone Number: 302-831-7231 
 
Email Address: megsions@udel.edu 
 
Other Investigators: Peter Coyle, PhD, DPT, PT; Emma Beisheim, DPT, PT, MS; Jefferson Cardoso, 
PhD, PT, MSc 
 
Investigator Assurance: 
 
By submitting this protocol, I acknowledge that this project will be conducted in strict accordance 
with the procedures described. I will not make any modifications to this protocol without prior 
approval by the IRB. Should any unanticipated problems involving risk to subjects occur during this 
project, including breaches of guaranteed confidentiality or departures from any procedures 
specified in approved study documents, I will report such events to the Chair, Institutional Review 
Board immediately.   
 
1.  Is this project externally funded? □ YES  X NO 
 
If so, please list the funding source: not applicable 
 
2. Research Site(s) 
 
X University of Delaware 
□ Other (please list external study sites) 
 
 
Is UD the study lead?  X YES □ NO (If no, list the institution that is serving as the study 
lead) 
 
3.  Project Staff 
Please list all personnel, including students, who will be working with human subjects on this 
protocol (insert additional rows as needed): 
 
NAME 
ROLE 
HS TRAINING COMPLETE? 
J. Megan Sions, PhD, DPT, PT 
Principal investigator 
yes 
Peter Coyle, DPT, PT 
PhD student 
yes 
John Horne, CPO 
Clinical partner 
yes 
Ryan Pohlig, PhD 
Biostatistician 
yes 
Gregory E Hicks, PhD, PT 
Senior research mentor 
yes 
Emma Beisheim, SPT 
PhD student/student physical 
therapist 
yes 

2 
 
DeJa Crippen 
Undergraduate research 
assistant 
yes 
Marybeth Clancy 
Undergraduate research 
assistant 
yes 
Michayla Petel 
Undergraduate research 
assistant 
yes 
Daniel Awokuse 
Undergraduate research 
assistant 
yes 
Melissa Capurro 
PT student 
yes 
Nattie Chan 
PT student 
yes 
Jefferson Cardoso, PhD, PT, 
MSc 
Post-doctoral researcher 
yes 
Abdulmohsen Alroumi, BScPT, 
MSc 
PhD student 
yes 
Caitlin Airey 
Undergraduate research 
assistant 
yes 
Jessica Mungia 
Undergraduate research 
assistant 
yes 
Erin Anderson 
Undergraduate research 
assistant 
yes 
Phoebe Balascio 
Undergraduate research 
assistant 
yes 
Macy Oteri 
Undergraduate research 
assistant 
yes 
 
4.  Special Populations 
Does this project involve any of the following: 
 
Research on Children?   no 
 
Research with Prisoners? no 
 
If yes, complete the Prisoners in Research Form and upload to IRBNet as supporting documentation 
 
Research with Pregnant Women? no 
 
Research with any other vulnerable population (e.g. cognitively impaired, economically 
disadvantaged, etc.)? please describe      no 
 
5.  RESEARCH ABSTRACT Please provide a brief description in LAY language (understandable to 
an 8th grade student) of the aims of this project.  
 
Up to 48% of adults following a lower-limb amputation will die within the upcoming year.1 Lack of 
physical activity (exercise) contributes to high death rates.2,3 It is recommended that younger (and 
middle-aged) adults without a health condition walk 10,000 steps/day to reduce the risk of chronic 
health conditions, while recommendations are 7,100 steps per day for older adults and those with 
chronic health conditions.4 Adults with a lower-limb amputation walking about 21-43%5-7 of the 
recommended 7,100 steps/day.4 Step activity monitors, such as the StepWatch (a research-grade 
accelerometer) and the FitBit (a commercially-available monitor) provide a means of evaluating 
physical activity, which is important since patients tend to over-estimate their level of physical 
activity.8,9 Activity monitor use, however, may not be possible in every healthcare practice setting, as 
monitors may cost $100-$600 and someone must remove the data from the monitor, interpret the 

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data, and enter the data into the patient’s medical record. Therefore, physical activity questionnaires, 
where the patient self-reports their physical activity, are ideal in a clinical setting. Unfortunately, to 
date, there has been little research looking at the accuracy of physical activity questionnaires in 
patients with lower-limb amputations and how these questionnaires measure up to data obtained 
from step activity monitors.   
 
In addition to 7,100 steps/day, adults with mobility-limiting, chronic conditions (including individuals 
with lower-limb amputations) should participate in ≥150 minutes of moderate-intensity physical 
activity per week, with activity in ≥10 minutes per bout.4 Moderate-intensity activity has been defined 
as 3 metabolic equivalents (METs).10 One MET is equal to the amount of oxygen one consumes at 
rest, so 3 METs means that one is consuming 3 times the amount of oxygen one would consume at 
rest. In healthy adults without a medical condition this equates to walking 2.6-2.7 mph11 or 100 
steps/minute12, while for adults with an amputation of the leg below-the-knee (i.e. a transtibial 
amputation), 1.47 mph or 86 steps/minute has been reported to equal 3 METs.10 Maximal walking 
speeds for adults with lower-limb amputations, specifically those who have lost their limb due to poor 
blood circulation may be ≤1.67 mph,13-15 so one must question if walking 1.47 mph for an extended 
time is possible for these patients. We believe that 1.47mph is greater than 3 METs for adults with a 
lower-limb amputation who have other medical issues, such as diabetes and peripheral vascular 
disease, and who are deconditioned and not participating in physical activity.  
 
It is important to know what speed (mph) and cadence (steps/minute) equals 3 METs in adults with a 
lower-limb amputation with other medical conditions who are currently inactive. We believe that 
these patients represent the vast majority of patients that healthcare providers encounter and must 
council regarding increasing their physical activity. Providers need to know what speed and cadence 
is equal to 3 METs for inactive patients with limb loss with other medical conditions, so that providers 
can appropriately advise their patients and prescribe exercise. 
 
Walking exercise may occur over-ground or on a treadmill. When an individual with a lower-limb 
amputation is walking over-ground, their right-to-left side walking pattern will be more asymmetrical 
(uneven) when compared to when they are walking on a treadmill.16 When walking is more 
symmetrical side-to-side (even), the patient may have to expend more energy. Energy expenditure 
can be assessed as the amount of oxygen consumed, which can be obtained while wearing a mask 
that evaluates your breathing while walking. Among adults with a lower-limb amputation, energy 
expenditure studies have generally used treadmills to look at energy expenditure.17-20 Over-ground 
versus treadmill conditions, however, are different,21 and as such, what equals 3 METs (speed, 
cadence) in each walking condition may vary.22  
 
Further, no studies have compared the energy cost of walking in adults who are inactive with a 
lower-limb amputation to age-, sex-, and body mass index (computed from height and weight) -
matched adults without an amputation. While studies have evaluated the impact of aging52,53 and 
limb length of the amputated limb49,51 on energy expenditure, few have evaluated modifiable factors 
that may impact energy expenditure among adults with lower-limb amputation.56,57 Similarly, little 
research has explored modifiable factors that may impact physical activity levels.54,55  
 
The project’s goal is to provide knowledge that will improve physical activity prescription for inactive 
adults with a single, below-the-knee amputation (i.e. transtibial amputation).  
 
Successful completion of the project may provide healthcare providers with (1) a physical activity 
self-report measure that can be used in clinical practice for patients with a lower-limb amputation, (2) 
gait speed (mph) for prescribing moderate-intensity over-ground and treadmill walking during the 
rehabilitation of patients with lower-limb amputations, and (3) cadence (steps/minute), for evaluating 
and monitoring moderate-intensity physical activity via step activity monitors, for inactive adults with 
a lower-limb amputation.  

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We will provide the first objective data that looks at the additional energy expenditure necessary for 
inactive adults with a lower-limb amputation who are using a prosthesis to walk short-distances as 
compared to able-bodied adults; this data may be used for the development of future prosthetic 
components that reduce energy expenditure. We will explore factors that may be linked to energy 
expenditure and physical activity among adults with and without a lower-limb amputation. 
 
______________________________________________________________________________ 
Specific Aim 1: Evaluate reliability and validity of physical activity self-report measures (i.e. 
International Physical Activity Questionnaire, Incidental and Planned Exercise Questionnaire-past 
week23,24) as compared to physical activity characteristics obtained via step activity monitors (i.e. 
time spent walking/day, walking bout duration, walking bouts/day) among inactive adults with a 
single-limb amputation (n=20). 
Hypothesis: H1a: Both self-report measures will have excellent test-retest reliability (ICCs ≥.75). 
H1b: At least 1 self-report measure will demonstrate validity with ≥ 2 physical activity characteristics.   
 
Specific Aim 2: Determine what gait speed (mph) and cadence (steps/minute) constitute 3 METs, 
i.e. moderate-intensity activity, among inactive adults with a single, below-the-knee amputation 
during over-ground and treadmill walking (n=20). 
Hypothesis: H2a: 3 METs will occur at slower speeds during treadmill walking as compared to over-
ground walking. H2b: 3 METs will occur at slower cadences during treadmill walking as compared to 
over-ground walking. 
 
Specific Aim 3: Evaluate differences in energy expenditure based on oxygen consumption between 
inactive adults with a single, below-the-knee amputation (n=20) and matched controls (n=20) during 
short bouts of over-ground and treadmill walking at self-selected gait speeds, 75% and 125% of self-
selected gait speeds. 
Hypothesis: H3: Energy expenditure will be significantly greater at all walking speeds for adults with 
a limb amputation as compared to controls (a) over-ground and (b) during treadmill walking (p≤0.05). 
 
Specific Aim 4: Explore modifiable factors that may impact energy expenditure (assessed via 
oxygen consumption) including comorbidities, fatigue, sleep disturbance, balance, functional lower 
extremity strength, functional mobility, and agility among adults with (n=20) and without a unilateral 
below-the-knee amputation (n=20). 
Hypotheses: For both adults with and without a below-the-knee amputation (after controlling for 
covariates):  
H4a: Comorbidities: Energy expenditure will be significantly greater at all walking speeds and for 
both walking conditions (over-ground and treadmill) for adults with greater comorbidity burden as 
assessed with the Cumulative Illness Rating Scale. 
H4b: Fatigue: Energy expenditure will be significantly greater at all walking speeds and for both 
walking conditions (over-ground and treadmill) for adults who indicate fatigue on the PROMIS-29, as 
compared to those who do not indicate fatigue. 
H4c: Sleep Disturbance: Energy expenditure will be significantly greater at all walking speeds and 
for both walking conditions (over-ground and treadmill) in adults who indicate sleep disturbance on 
the PROMIS-29, as compared to those who do not indicate sleep disturbance. 
H4d: Balance: Energy expenditure will be significantly greater at 125% of self-selected gait speed for 
treadmill walking in individuals with balance deficits, as indicated by decreased Functional Reach 
Test distance and decreased time until loss of balance during the modified Clinical Test of Sensory 
Integration in Balance conditions 3 and 4 (foam, eyes open and foam, eyes closed). 
H4e: Functional Lower Extremity Strength: Energy expenditure will be significantly greater for self-
selected and 125% of self-selected walking speed for both walking conditions (over-ground and 
treadmill) in adults with decreased functional lower extremity strength, defined as slower 5 Times 

5 
 
Repeated Chair Rise times. 
H4f: Functional Mobility: Energy expenditure will be significantly greater at for walking at 125% of 
self-selected speed for both walking conditions (over-ground and treadmill) in adults with decreased 
functional mobility, defined as increased L-test time.   
H4g: Agility: Energy expenditure will be significantly greater for walking at 125% of self-selected 
speed for treadmill walking in adults with agility deficits, defined as slower Four Square Step Test 
times and Figure-of-8 Walk Test times. 
 
*We expect that relationship may be stronger among adults with a unilateral below-the-knee 
amputation, but we are not powered to explore between-group differences. In fact, Aim 4 (and Aim 
5) is (are) exploratory, and we are looking for trends in differences.*  
 
Specific Aim 5: Explore modifiable factors that may impact physical activity, as assessed with step 
activity monitors, including comorbidities, balance-confidence, fatigue, sleep disturbance, balance, 
functional lower extremity strength, functional mobility and agility among adults with (n=20) and 
without a unilateral below-the-knee amputation (n=20).  
Hypotheses: For both adults with and without a below-the-knee amputation (after controlling for 
covariates):  
H5a: Comorbidities: Average daily step counts will be significantly lower for adults with greater 
comorbidity burden, as assessed with the Cumulative Illness Rating Scale. 
H5b: Balance-Confidence: Average daily step counts will be significantly lower for adults who have 
lower balance-confidence per the Activities-Specific Balance Confidence Scale. 
H5c: Fatigue: Average daily step counts will be significantly lower for adults who indicate fatigue on 
the PROMIS-29, as compared to those who do not indicate fatigue. 
H5d: Sleep Disturbance: Average daily step counts will be significantly lower in adults who indicate 
sleep disturbance on the PROMIS-29, as compared to those who do not indicate sleep disturbance. 
H5e: Balance: Average daily step counts will be significantly lower in adults with decreased 
Functional Reach Test distance and adults who are unable to maintain balance for 30 seconds 
during m-CTSIB conditions 3 and 4 (foam, eyes open and foam, eyes closed). 
H5f: Functional Lower Extremity Strength: Average daily step counts will be significantly lower in 
adults with decreased lower extremity functional strength, defined as slower 5 Times Repeated 
Chair Rise times. 
H5g: Functional Mobility: Average daily step counts will be significantly lower in adults with 
decreased functional mobility, defined as increased L-test times. 
H5h: Agility: Average daily step counts will be significantly lower in adults with worse agility as 
indicated by slower Four Square Step Test times and Figure-of-8 Walk test times. 
 
Specific Aim 6: Explore the relationship between gait asymmetry, as quantified by spatio-temporal 
and 3D kinematic parameters (e.g. cadence, stance and swing time, step length, and joint position), 
and energy expenditure among inactive adults with a single, below-the-knee amputation (n=20) 
during treadmill walking at self-selected and fast walking speeds.  
Hypothesis: Energy expenditure will be greater among inactive adults with a single, below-the knee 
amputation who demonstrate greater side-to-side differences in walking pattern during treadmill 
walking at both self-selected and fast walking speeds (p<0.05).  
 
Specific Aim 7: Compare side-to-side differences in walking pattern (e.g. speed, step length, and 
joint position) between inactive adults with a single, below-the-knee amputation (n=20) and age-
matched controls (n=20) during over-ground and treadmill walking using the APDM Mobility Lab 
software.  
Hypothesis: For both over-ground and treadmill walking conditions, inactive adults with a single, 
below-the knee amputation will demonstrate greater side-to-side differences in walking pattern 
compared to age-matched controls (p<0.05).  

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Specific Aim 8: Explore the relationship between inspiratory muscle endurance, as quantified by an 
individual’s sustained maximal inspiratory pressure (SMIP), and energy expenditure among inactive 
adults with a single, below-the-knee amputation (n=20) during treadmill walking at self-selected and 
fast walking speeds.  
Hypothesis: Energy expenditure will be greater among inactive adults with a single, below-the knee 
amputation who demonstrate decreased SMIP values (p<0.05).  
 
Specific Aim 9: Compare differences in inspiratory muscle endurance (measured by sustained 
maximal inspiratory pressure, or SMIP) between inactive adults with a single, below-the-knee 
amputation (n=20) and age-matched controls (n=20) using the PrO2 device.  
Hypothesis: Inactive adults with a single, below-the knee amputation will demonstrate decreased 
SMIP values compared to age-matched controls (p<0.05).  
 
Specific Aim 10: Compare differences in inspiratory muscle endurance (measured by sustained 
maximal inspiratory pressure, or SMIP) between inactive adults with a single, below-the-knee 
amputation who have low back pain compared to those who do not report pain.  
Hypothesis: Inactive adults with a single, below-the knee amputation who experience low back pain 
will demonstrate decreased SMIP values compared to individuals with a single, below-the-knee 
amputation who do not have pain (p<0.05).  
____________________________________________________________________________ 
 
6.  PROCEDURES Describe all procedures involving human subjects for this protocol.  Include 
copies of all surveys and research measures. 
 
Overview: We propose to conduct a cross-sectional study of 22 adults with a unilateral transtibial 
amputation as compared to 20 sex-, age- (+/- 5 years), and body mass index- (+/- 5 kg/m2) matched 
controls. This one-time session is projected to take ~ 2hours on-site at the University of Delaware on 
the STAR campus within the Department of Physical Therapy.   
 
Once contact is made with potential participants, inclusion and exclusion criteria will be examined in 
2 phases, first over the telephone using a structured questionnaire, and then on-site by a research 
team member to validate inclusion and exclusion criteria obtained by telephone.  Prior to telephone 
screening, verbal consent will be obtained from the participant.  The on-site screening will occur after 
individuals have signed the informed consent.   
 
All Participants will complete a series of questionnaires that will be sent via a mailing packet prior to 
the on-site evaluation. Questionnaires will take about 30 minutes to complete. Questionnaires 
included in this Mailing Packet will be the: 
 
1. Demographics Mailing Sheet: Will provide pertinent demographic information necessary for 
characterizing and matching participants (i.e. age, sex).   
2. Medical History Checklist: We would like to have participants complete this questionnaire as 
it will improve the efficiency and accuracy of the Cumulative Index Rating Scale.50  Further, it 
will alert the physical therapist to any relevant problems that should be consider during 
physical performance testing and when testing energy expenditure during the 2 walking 
conditions.   
3. Medication Sheet: Medication review using this sheet prior to physical performance testing 
and testing of energy expenditure during the 2 walking conditions will enhance patient safety 
and allow for appropriate interpretation of vital sign responses. This sheet will also allow 
increased efficiency and accurate scoring for the Cumulative Illness Rating Scale regarding 
comorbidities.50      
4. Activities Specific Balance Confidence Scale (ABC): The ABC is a valid32 16-item 

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questionnaire where individuals rate how confident they are that they will not lose their 
balance or become unsteady with various ambulatory activities on a 0-100% scale, where 
0=no confidence and 100%=complete confidence.27  
5. Patient-Reported Outcomes Measurement Information System (PROMIS-29): The PROMIS-
29 is a subset of the PROMIS assessment of self-reported health29 that measures quality of 
life based on physical function, pain interference, fatigue, sleep disturbance, anxiety, 
depression, and social participation.30,31 Individuals with lower-limb loss have been shown to 
score significantly lower on physical function, pain interference, and participation in social 
role subscales when compared to individuals without lower limb amputation.31  
6. International Physical Activity Questionnaire – Long Form (IPAQ)*: The questionnaire, 
designed for adults ages 18-65, consists of 31 items assessing physical activity in four 
domains: transportation, work, household and gardening tasks, and leisure time.33 It is a 
valid and reliable measure of self-reported physical activity level in healthy adults34; however, 
psychometric properties have not been established for use in individuals with lower-limb 
amputation. We will use this measure to compare self-reported physical activity levels to 
objective physical activity characteristics obtained from 7-days of monitoring via step-activity 
monitors.  
7. Incidental and Planned Exercise Questionnaire-past week*: This questionnaire has 10 items 
that ask about exercise type, intensity, and duration in the past week. 
 
*These 2 questionnaires will be provided to the participant at the end of the on-site evaluation.  
Participants will be asked to re-complete these questionnaires at the end of their 7 days of activity 
monitoring and return in the envelope with the step activity monitor and activity monitor log. It is 
projected that re-completion of these 2 questionnaires will take < 10 minutes.  
 
Individuals with lower-limb amputations will also complete the following:   
8. Houghton Scale of Prosthetic Use48: The questionnaire has 4 items related to wear duration, 
use, and perceived stability.28 Total scores range from 0-12 with higher scores indicating 
better function.28 Scores ≥9/12 suggest the individual is a community-ambulator. This 
questionnaire will help to characterize the participants with limb-loss in our sample. 
 
Questionnaires completed by participants who opt not to participate in the study (i.e. do not complete 
the informed consent) or who are deemed ineligible on-site will be shredded and placed in the trash 
(or given back to the participant to take home). This information will not be retained by the research 
staff. Informed consent documents will be retained in a locked file available only to research 
personnel. Participants will be given a copy of the informed consent for their records. Individuals with 
lower-limb amputations will also be asked to sign a HIPPA form. A copy of this form will be given to 
these research participants with a lower-limb amputation. The HIPPA form will request that the 
participant agree to share their medical records to allow determination of their current prosthetic 
components, to control for this factor during the data analysis. Specifically, we would like to control 
for the type of foot, passive or active and the type of suspension system, as these factors may 
impact energy expenditure.  Only the minimal necessary information to conduct the research will be 
requested. 
 
Standardized On-site Evaluation. During the on-site evaluation, a trained research team member 
will conduct a standardized clinical examination that will include review of questionnaires, vital signs, 
body anthropometric measurements, and balance and physical performance testing.  Demographics 
information including pain and socket fit comfort score will be recorded. Patients will be asked 
general questions about their amputation. In the event that such questioning results in an emotional 
response, the examiner will refrain from further questioning that may increase participant distress. 
Importantly, the PI will specifically train examiners in questioning with sensitivity and role-play how to 
handle various emotional responses during questioning. The physical examination will include 

8 
 
assessment of vital signs (i.e. heartrate, blood pressure, and respiratory rate) to ensure 
appropriateness for participation in balance and physical performance testing and assessment of 
height and weight for calculation of body mass index using a medical-grade scale.   
1. Cumulative Illness Rating Scale (CIRS): An index of co-morbidity burden used to quantify 
comorbidities based on significance of the condition and medication use; co-morbidities are a 
known factor related to real-world walking.37 Administration of the CIRS will take less than 8 
minutes.   
2. Residual Limb Length Measurement: Residual limb length has been proven to affect energy 
expenditure in individuals with lower limb amputation.49 Increased residual limb length may 
contribute to a decrease in the metabolic cost of walking and an increase in comfortable 
walking speed due to greater preservation of lower extremity muscle mass.49 We will include 
this measure to allow for control of this non-modifiable covariate during energy expenditure 
analyses.  
3. Inspiratory Muscle Endurance Measurement: To function properly, the respiratory system 
relies on the strength and power of the muscles responsible for breathing air into the body 
(i.e. the inspiratory muscles). Inspiratory muscle dysfunction, which may result from physical 
inactivity, major surgery, and prolonged periods of bedrest58, may consequently reduce an 
individual’s ability to effectively use oxygen during activity, causing a decrease in physical 
activity capacity and an increase in energy expenditure during physical tasks.59 Breathing 
muscle endurance will be measured using the PRO2 Hand Built device according to the Test 
of Incremental Respiratory Endurance (TIRE) protocol.60 Using this protocol, participants will 
be asked to exhale (breathe out) as much air as possible, then breathe into a small, 
handheld device as hard and as long as possible. This typically lasts between 10 and 20 
seconds, and real-time feedback on breathing pressure during testing will be provided 
through an application on a tablet. The software will generate the maximal inspiratory 
pressure, MIP, as well as the sustained maximal inspiratory pressure, SMIP, and duration of 
inspiration. These measures will be included to comprehensively assess cardiopulmonary 
function and relate differences in breathing muscle endurance to oxygen consumption, 
physical performance, and pain.   
4. Physical Performance Testing 
1. Repeated Chair Stands: Individuals are asked to stand up and sit down from a chair 
without using their arms as quickly as possible 5 times39. This measure will be used as a 
functional assessment of lower extremity strength40, which is a factor that may impact 
walking.   
2. Modified Clinical Test of Sensory Interaction in Balance (m-CTSIB): This measure 
assesses sensory input integration for balance maintenance when one or more sensory 
systems is compromised.41 
3. Functional Reach Test: Individuals are asked to reach forward as far as possible without 
moving their feet and the maximal distance reached is recorded.42 This test has been 
shown to be not only reliable and valid, but to not have a floor/ceiling effect for 
assessment of balance among individuals with unilateral amputations like other balance 
measures.42  
4. Four Square Step Test (FSST): The FSST is a standing dynamic balance test used to 
assess lower extremity motor control.43 A four-square set-up is created using canes, and 
participants are asked to step as quickly as possible into each square in a specific 
pattern, requiring steps to be taken forward, backward, and sideways to the right and left 
(which assesses agility).43 A score of >24 seconds indicates increased fall risk in 
individuals with transtibial amputation.44  
5. Figure of 8 Test: A complementary test to gait speed designed to assess both straight 
and curved path walking ability. Individuals are asked to walk around cones to complete 
a “figure-of-8”.45 Time to complete the test is recorded as well as number of steps and 

9 
 
the participant’s ability to stay close to the cones.45 This measure will be used to assess 
each individual’s ability to navigate tight corridors and as a test of agility.   
6. L-Test of Functional Mobility: A reliable and valid46 clinical test where participants will be 
asked to stand from a chair, walk 3 meters, turn 90 degrees, walk an additional 7 meters, 
turn 180 degrees and return to sitting in a chair.46 This measure will be used to assess 
mobility, balance, turning, and walking ability (i.e. functional mobility).   
 
Individuals with lower-limb amputations will also complete the following:   
7. Amputee Mobility Predictor: This is a reliable and valid, performance-based battery that can be 
used to assess functional capacity of individuals with lower-limb loss who are utilizing a prosthesis.38 
Tasks include those that challenge the individual’s balance, transfers, and walking. Scores range 
from 0-47 with use of a prosthetic device, where 47 indicates a perfect score.38 This measure will be 
used to help characterize our participants with limb amputations, since this measure is universally-
used in this patient population to determine functional mobility level.   
 
Pre-Walking Set-Up 
Participants will be fit with a mobile gait analysis system (APDM Mobility Lab) that will assess gait 
symmetry during the over-ground and treadmill walking tests that follow. Participants will be fit with 
APDM Mobility Lab sensors at the following locations: sternum, posterior surface of both wrists, 
lumbar spine, anterior surface of both thighs, anterior surface of both lower legs (and/or the sound 
lower leg and the prosthetic leg), and the dorsal surface of both feet (and/or the sound foot and 
prosthetic foot). This will take approximately 5 minutes.  
 
The APDM software will be used to collect spatio-temporal measurements, such as stride length and 
velocity, as well as three-dimensional kinematic measurements, including joint position and 
acceleration throughout the gait cycle and maximal toe clearance during the swing phase of gait. 
Information regarding trunk sway and arm swing will also be collected.  
 
Participants will also be fit with a Polar heartrate monitor, worn around the chest on the skin, to allow 
vital sign monitoring during the over-ground and treadmill walking conditions. The examiner will wear 
the wristwatch monitoring unit during the walking bouts for ease of monitoring.    
 
Gait Speed Pre- and Post-Walking Conditions Assessment 
We will use a computerized walkway system (GaitRite) to obtain self-selected (3 trials) and fast-
walking speeds (3 trials) as well as other spatiotemporal parameters of gait immediately before and 
after each walking condition. APDM sensor data collection will also occur during self-selected and 
fast walking trials over the GaitRite system. By comparing pre- and post-walking gait speeds, we 
may be able to determine if the participant experienced fatigue during the walking bout. This will take 
<3 minutes per collection; there will be 4 collections total.  
 
Metabolic Cost Testing Procedures. Participants will have their metabolic energy expenditure (i.e. 
oxygen consumption) measured as they walk at various speeds within the Department of Physical 
Therapy. Individuals with a unilateral transtibial amputation will complete the following two tests in a 
randomized order (controls will complete the tests in the same order as their matched participant 
with a unilateral transtibial amputation): 
1. 3-Stage Walking Metabolic Gas Analysis on Treadmill Test: Oxygen consumption 
measurements will be performed with the participant walking on a treadmill, set to three 
different speeds. After being fitted with the metabolic gas analysis equipment, participants 
will sit in a chair for five minutes to collect baseline oxygen consumption. Then, participants 
will walk on the treadmill at a constant speed that will be derived from the participant’s self-
selected gait speed as measured by the GAITRite™ walkway. In stage 1, participants will 
walk at 75% of their self-selected gait speed for 2.5 minutes. In stage 2, participants will walk 
at 100% of their self-selected gait speed for 2.5 minutes. In stage 3, participants will walk at 

10 
 
125% of their self-selected gait speed for 2.5 minutes. These speeds were selected based 
on pilot data in 44 patients with a unilateral transtibial amputation who walked on average at 
a mean self-selected speed of .88 m/sec (95% CI: .80, .95) if they were K3 functional level 
and 1.16 (1.06, 1.25) if they were K4 functional level and a mean fast gait speed of 1.15 
(1.05, 1.25) and 1.53 (1.38, 1.68) if they were K3 and K4 functional level, respectively. 
Available safety features will be used with treadmill testing (e.g. lanyards, emergency stops).  
 
In-between stages, participants will sit until their heart rate returns below 100 beats per 
minute. This methodology has been derived from prior studies with similar purposes.12, 25, 
26 During each stage, the investigator will measure the number of steps taken using a 
hand tally counter; step cadence (i.e. steps/minute) will be computed from this value.  
 
The Oxycon Mobile™ (CareFusion™, San Diego, CA) Portable VO2 Measurement 
system will be used to collect expired air via a facemask to measure VO2 uptake; this 
device is a lightweight, non-cumbersome machine used for portable metabolic 
measurement. The O2 and CO2 analyzers will be calibrated at the beginning of each test 
using standard calibration gases (16% O2, 4% CO2, balance nitrogen; CareFusion™, 
San Diego, CA). The auto calibration function will be used to calibrate volume 
(CareFusion™, San Diego, CA). 
 
2. 3-Stage Walking Metabolic Gas Analysis Over-Ground Test: Oxygen consumption 
measurements will be performed with the participant walking over ground in an uncarpeted 
corridor on a course consisting of two cones, 20-meters apart. Similar to the treadmill test, 
participants will be asked to walk at three different speed. After being fitted with the 
metabolic gas analysis equipment, participants will sit in a chair for five minutes to collect 
baseline oxygen consumption. Then, participants will complete the walking test in three 
stages. In stage 1, participants will be instructed to walk at their “slow” speed for 2.5 minutes. 
In stage 2, participants will be instructed to walk at their “usual, comfortable” speed for 2.5 
minutes. In stage 3, participants will be asked to walk at their “brisk” speed for 2.5 minutes. 
In between stages, participants will sit until their heart rate returns below 100 beats per 
minute. This methodology has been derived from prior studies with similar purposes.12, 25, 26  
Again, the Oxycon Mobile™ will be used to complete these measurements. During each 
stage, the investigator will measure the number of steps taken using a hand tally counter; 
step cadence will be computed from this value (i.e. steps/minute). Also, the distance the 
participant covers within each stage will be recorded. 
 
Step Activity Monitoring.  
At the conclusion of the on-site evaluation, all participants will be equipped with the StepWatch 
Activity Monitor. The activity monitor will be fastened near the ankle of the prosthesis using the 
straps included with the monitor (or in the case of controls, around the ankle joint of the right side).  
 
Upon completion of the on-site evaluation, participants will be sent home with the activity monitor for 
a 7-day activity observation period. Participants will be instructed to perform their regular daily 
activities, wearing the monitor at all times that they are wearing their prosthesis.  During the 
observation period, the activity monitor will record the number of steps the participants take.  
Participants will be provided with a pre-paid and addressed padded envelope and instructed to mail 
the activity monitor back after 7 days. Upon return of the monitors, study investigators will extract the 
step count data from the activity monitors. The 2 physical activity questionnaires will also be sent 
back re-completed (after 7 days) in these pre-paid envelopes, which will allow us to evaluate test-
retest reliability of these questionnaires. 
 
Review of Data. We will discuss and provide participants with blood pressure data, and physical 
performance data via written handouts (uploaded) at the conclusion of their on-site examination. 

11 
 
Participants with inappropriate vital signs will be managed in accordance with the policies outlined 
on the blood pressure screening handout; when necessary, the examiner will contact the provider. 
 
7.  STUDY POPULATION AND RECRUITMENT 
Describe who and how many subjects will be invited to participate. Include age, gender and 
other pertinent information.   
 
We will recruit 22 (males and females) with a unilateral (i.e. single limb), transtibial (i.e. below-the-
knee) amputation through the UD Amputee Clinic, Independence Prosthetics-Orthotics, Inc., and 
from the local community using fliers (uploaded), print advertisements (uploaded), and Consent-to-
Contact forms (uploaded). Given the prevalence of amputations is greater in males, we expect that 
the sample will be predominantly male, but we will have no inclusion/exclusion criteria related to sex. 
Specifically, patients with unilateral transtibial amputations who receive services at Independence 
Prosthetics-Orthotics, Inc. or through the UD Amputee Clinic will be supplied a Consent-to-Contact 
form. This form will include contact information (first and last name; telephone numbers; best time to 
call) that will be faxed/emailed/placed in a folder for Dr. Sions if they are interested. Dr. Sions will 
facilitate a phone screening of the individual after supplying the participant with additional study 
information (see verbal recruitment script). Information from individuals who are ineligible or who opt 
not to participate after the phone screen or after receiving additional study information will be 
shredded.  
 
We will also contact individuals with unilateral transtibial amputations who have previously signed 
consents to be re-contacted for research purposes while receiving services at the University of 
Delaware Physical Therapy Clinic. We will utilize the verbal script for recruitment (uploaded) in these 
cases.   
 
20 controls will be recruited as age-, sex-, and body mass index-matched controls.  
 
Telephone screening will be used to determine preliminary eligibility and information will be reviewed 
on-site (telephone screen uploaded). 
 
Inclusion Criteria: All Participants  
1. English-speaking and -reading: Due to lack of feasibility of conducting evaluation in other 
languages. 
2. Ages 18-60 years: Adults > 60 years may have age-related changes in energy expenditure 
with walking. Children under 18 years may still be experiencing limb growth and maturation 
that effect walking.   
3. Saltin-Grimby Physical Activity Level47 of I or II: Goal is to sample individuals who are 
sedentary rather than presently active.    
 
Inclusion Criteria: Individuals with Below-the-Knee Amputations  
1. Below-the-knee amputation: Individuals with above-the-knee amputations are known to 
expend greater energy when walking than those with longer residual limbs.  
2. Currently wearing a prosthesis with use of an assistive device no greater than a cane: 
Necessary for proposed testing. 
3. Wearing prosthetic at least 8 hours per day and inside and outside the home: This criteria 
will help to ensure that we capture adults who are beyond the initial weaning into a prosthetic 
and who are prosthetic users rather than nonusers.    
 
Inclusion Criteria: Controls 
1. Pain-free in the legs and low back regions: Pain in these regions could be a confounding 
variable for the proposed testing. 
2. Walk without assistive device: Goal is to capture able-bodied individuals for comparison 

12 
 
purposes.  
 
Attach all recruitment fliers, letters, or other recruitment materials to be used. If verbal 
recruitment will be used, please attach a script.  Uploaded 
 
Describe what exclusionary criteria, if any will be applied. 
 
Exclusion Criteria: All Participants  
1. Current infections/illnesses: May affect O2 consumption with walking, physical activity, 
and/or performance testing. 
2. Significant cardiovascular, neurological, or pulmonary condition: Such conditions may affect 
O2 consumption, physical activity, and/or performance testing. 
3. Uncontrolled blood pressure or diabetes: It may not be safe for these adults to participate in 
exercise testing. 
 
Exclusion Criteria: Individuals with Below-the-Knee Amputations  
1. Amputation of sound limb: We will exclude individuals with bilateral amputations, which is a 
known contributor to increased energy expenditure and impaired balance.   
2. Current issues with residual limb affecting ability to walk or for which individual is receiving 
treatment (i.e. open skin lesion, physical therapy for initial gait training with new prosthetic) or 
has weight-bearing restriction. 
 
Describe what (if any) conditions will result in PI termination of subject participation. 
 
Termination of participation would only occur under a circumstance in which it became clear that the 
participant could not participate in a safe manner, such as unstable or abnormal vital signs or 
significant balance impairments resulting in questionable safety, particularly with balance testing, 
physical performance testing, or treadmill testing.   
 
8.  RISKS AND BENEFITS 
List all potential physical, psychological, social, financial or legal risks to subjects (risks 
listed here should be included on the consent form). 
 
In your opinion, are risks listed above minimal* or more than minimal? If more than minimal, 
please justify why risks are reasonable in relation to anticipated direct or future benefits. 
 
(*Minimal risk means the probability and magnitude of harm or discomfort anticipated in the research are not 
greater than those ordinarily encountered in daily life or during the performance of routine physical or 
psychological examinations or tests) 
 
Minimal risks to the subjects are expected. The risks of the testing might include soreness and a 
temporary increase in skin, muscle, or joint pain. A small risk of a fall during balance testing, physical 
performance testing, and walking assessments is present. Participants will be free to withdraw from 
participating in the study at any time if they are uncomfortable with any of the procedures. Although 
no other risks or changes in the existing minimal risks are anticipated, participants will be informed if 
any new information arises regarding risks of participation that may affect their decision to continue 
in the study.  
 
What steps will be taken to minimize risks? 
 
To minimize soreness risks, participants will be asked to complete the minimal number of trials 
necessary to familiarize individuals with the testing equipment and assessment procedures and 
obtain a valid test. For balance, physical performance, and walking tasks, participants will be 

13 
 
appropriately supervised by a research member trained in participant guarding to minimize fall risk. 
The PI will be available by phone during all data collections. The testing done within the context of 
this study is used on a daily basis in the clinical setting, except that patients typically do not receive 
assessment of O2 consumption during walking.   
 
Describe any potential direct benefits to participants. 
Investigators will review results of blood pressure screening with each participant and review the 
results of each participants’ functional performance testing. If the vital sign screening indicates a 
need for an immediate referral, the examiner will contact the primary care provider and the patient 
will not be eligible to participant in further testing.  Participants will be given blood pressure 
screening and physical performance handouts to share with their medical providers.  
 
Describe any potential future benefits to this class of participants, others, or society. 
Potential benefits include establishment of speed (mph) and cadence (steps/min) for sedentary 
adults with lower-limb amputations that corresponds to 3 METs, i.e. moderate-intensity physical 
activity, which may be used when initiating an exercise program to enhance physical activity. It is 
possible that a physical activity questionnaire will be found to be reliable and valid for this patient 
population for assessment of physical activity, which will aide clinicians in evaluation of patients with 
limb loss. Objective data assessing the additional energy expenditure necessary for inactive adults 
with a lower-limb amputation to walk short-distances using a prosthesis may provide useful 
information for the development of future prosthetic components to reduce energy expenditure. 
Preliminary data evaluating modifiable factors related to energy expenditure and physical activity 
may help to inform future research studies.   
 
If there is a Data Monitoring Committee (DMC) in place for this project, please describe when 
and how often it meets. 
 
As this is a small project, there will not be a data monitoring committee. The Principal Investigator 
(Dr. Sions) will provide ongoing review of the accrued research data to ensure the safety of research 
participants and the provisions for protecting the privacy of participants and the confidentiality of 
research data.  
 
Dr. Sions, if not present during the on-site evaluations, will be made aware of any unexpected or 
adverse events immediately via phone. If an adverse event occurs, it will be reported immediately by 
a Principal Investigator to the University of Delaware Institutional Review Board (IRB) in accordance 
with the IRB’s stated policy for reporting adverse events in the IRB reference manual.  
 
The Principal Investigator will review subject recruitment and accrual with the research personnel 
conducting phone screenings on a monthly basis. The validity and integrity of the research data will 
be reviewed quarterly by the Principal Investigator. Ongoing review of scientific literature, related to 
the research will be performed by the Principal Investigator, to determine if changes to the study 
should be made given new information.  
 
9.  COMPENSATION 
Will participants be compensated for participation? 
Yes 
 
If so, please include details.  
Compensation will be provided to all participants for their time and participation in the study after the 
individual returns the electronic monitor(s) as monitor replacement costs exceed the $40 honorarium 
that will be given to participants. Compensation was determined based upon the time required for 
evaluation and wearing the step activity monitor for 7 days, as well as travel expenses to the onsite 

14 
 
evaluation. If participants do not complete all questionnaires and components of the on-site 
examination and 7-day activity monitoring, e.g. they complete some components but choose not to 
complete other components or they wear the monitor for less than 7 days, then their compensation 
will still be $25 (assuming that the activity monitor(s) is/are returned). 
 
10.  DATA 
 
Will subjects be anonymous to the researcher? No 
 
If subjects are identifiable, will their identities be kept confidential? (If yes, please specify 
how) 
 
Consent to contact forms, telephone demographics sheets, informed consent forms, and a copy of 
the participant’s handouts will be secured in locked cabinets within the Department of Physical 
Therapy and will accessible only to research personnel.  Names and contact information will be 
entered into an electronic database that will be stored on a password protected University 
maintained sever with regular and secured back-ups.  A separate electronic database with the 
participant’s name and contact information will be stored on a password protected University 
maintained server with regular and secured back-up if he/she agrees to be contacted for future 
studies.  
 
How will data be stored and kept secure (specify data storage plans for both paper and 
electronic files. For guidance see http://www.udel.edu/research/preparing/datastorage.html )    
 
All paper research records will be maintained in the Department of Physical Therapy (540 S. College 
Ave). Paper files will be secured in locked cabinets. De-Identified data will be entered from the paper 
records to a computerized database where all patients will be identified by a code number only.   
Research information will be indefinitely stored using a coded number. Only research personnel will 
have access to this data. There will be a single file linking participant name to number, which will be 
password protected and stored on a secured server, where only research members have access. 
Coded electronic data will be securely stored on a password-protected departmental server, as well 
as portable electronic devices that are securely stored in locked cabinets within the Department of 
Physical Therapy.   
 
How long will data be stored?  Data will be stored indefinitely. 
 
Will data be destroyed?  □ YES   X NO (if yes, please specify how the data will be destroyed)  
 
Will the data be shared with anyone outside of the research team?  □ YES   X NO (if yes, 
please list the person(s), organization(s) and/or institution(s) and specify plans for secure 
data transfer) 
 
How will data be analyzed and reported?  
 
Analyzed 
Analyses will be performed using SPSS statistical software packages with consultation of an 
experienced biostatistician (when needed). Descriptive statistics will be used to characterize the 
study sample. 
 
Specific Aim 1: To determine reliability, intra-class correlation coefficients (ICCs) with 95% 
confidence intervals (CIs) will be calculated to evaluate test-retest reliability of physical activity 

15 
 
questionnaires. To evaluate validity between the self-report questionnaire data and activity-monitor 
obtained data that is continuous (e.g. steps/day, total activity in minutes/day), we will use ICCs with 
95% CIs. We will quantify the relationship between the self-report data and activity-monitor data 
using Spearman’s correlation coefficients. Interpretation will be as follows: p≤.25=weak correlation, 
p=.26-.49=low correlation, p=.50-.69=moderate correlation, p≥.70=high correlation.   
 
Specific Aim 2: We will use receiver operating characteristic (ROC) curves to determine the minimal 
speed and cadence that corresponds to an oxygen consumption value of 10.5 mL/kg/min (i.e. 3.0 
METs), as this has been identified by the World Health Organization as 'moderate intensity' 
activity.10  
 
Specific Aims 3 and 6-10: We will use a MANOVA/MANCOVA to evaluate between-group 
differences with follow-up ANOVAs/ANCOVAs as appropriate (p≤0.05).  
 
Specific Aims 4/5: Regression models will be used to explore relationships between energy 
expenditure (or average daily step counts) and each of the modifiable factors of interest, while 
controlling for relevant non-modifiable covariates, e.g. age, residual limb length. 
 
Reported 
 
Dissemination of results will occur through conference presentations and manuscript publications in 
peer-reviewed journals. 
 
11. CONFIDENTIALITY 
 
Will participants be audiotaped, photographed or videotaped during this study? No 
 
How will subject identity be protected? 
 
The risk of breaching subject confidentiality will be minimized by identifying all participants by code 
numbers and by securing all data in locked files accessible only to research personnel. Neither the 
participant’s name or nor any identifying information will be used in any publication or presentation 
resulting from this study.  
 
Is there a Certificate of Confidentiality in place for this project?  (If so, please provide a copy). 
No 
 
12. CONFLICT OF INTEREST 
(For information on disclosure reporting see: http://www.udel.edu/research/preparing/conflict.html ) 
 
Do you have a current conflict of interest disclosure form on file through UD Web forms? 
 
Yes 
 
Does this project involve a potential conflict of interest*? No 
 
* As defined in the University of Delaware's Policies and Procedures ,a potential conflict of interest (COI) 
occurs when there is a divergence between an individual's private interests and his or her professional 
obligations, such that an independent observer might reasonably question whether the individual's 
professional judgment, commitment, actions, or decisions could be influenced by considerations of personal 
gain, financial or otherwise. 
 
If yes, please describe the nature of the interest: not applicable 

16 
 
 
13.  CONSENT and ASSENT 
 
X Consent forms will be used and are attached for review (see Consent Template under Forms and     
Templates in IRBNet) 
 
____ Additionally, child assent forms will be used and are attached. 
____ Waiver of Documentation of Consent (attach a consent script/information sheet with the 
signature block removed). 
____ Waiver of Consent (Justify request for waiver) 
 
14.  Other IRB Approval 
Has this protocol been submitted to any other IRBs? No  
 
If so, please list along with protocol title, number, and expiration date. Not Applicable 
 
15.  Supporting Documentation 
Please list all additional documents uploaded to IRBNet in support of this application. 
 
• 
Informed Consent Form – clean copy and track changes 
• 
Data Collection Form – On-site Evaluation (including updated Request for Participant 
Incentive form)  
• 
Continuing Review Form   
• 
Previously Approved Documents:  
o 
HIPAA Authorization Form 
o 
Advertisement 
 
Recruitment Flier with Pull Tabs_Controls 
 
Recruitment Flier with Pull Tabs_Amputees 
 
Recruitment Print Advertisement 
 
Consent to Contact Form 
o 
Other: Screening 
 
Verbal Script for Recruitment 
 
Telephone Demographics 
 
Telephone Screen  
o 
Mailing Packet Questionnaires 
 
Face Sheet 
 
Demographics Sheet 
 
Medical History Checklist 
 
Medication Sheet 
 
Activities Specific Balance Confidence Scale 
 
Patient-Reported Outcomes Measurement Information System 
(PROMIS-29) 
 
International Physical Activity Questionnaire (IPAQ)  
 
Incidental and Planned Exercise Questionnaire-past week  
 
Houghton Scale of Prosthetic Use 
 
Directions to UDPT Clinic 
o 
Other: Participant Handouts 
 
BP Screening 
 
Physical Performance Testing_Controls 
 
Physical Performance Testing_Amputees 
 
 

17 
 
 
 
 
 
 
 
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