bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Mental Rehearsal of Task Motor Activity and Mental Depiction of Task Outcome on Motor Skill Performance
Authors: Woolfolk Robert L. , Murphy Shane M. , Gottesfeld David , Aitken David
Published: August 2016

An investigation was carried out concerning the effect of imagery instructions on a simple motor skill accuracy task (putting a golf ball). Male college students (N = 50) were randomly assigned to one of six experimental conditions in a design that allowed the presence or absence of mental rehearsal of the physical movements involved in the task to be completely crossed with the imaginal depiction of task outcome (successful, unsuccessful, or no outcome component). A significant outcome by trials interaction was found on task performance. This finding reflected the degradation of performance in the conditions employing negative outcome imagery rather than any enhancement of performance by positive outcome imagery. Self-efficacy was found to be correlated with performance, but this association seemed to be a by-product of the strong relationships between these variables and performance on the previous trial. Results are discussed in relation to the existing literature, and future research directions are delineated.
The Development of an Instrument to Assess Cohesion in Sport Teams: The Group Environment Questionnaire
Authors: Carron A.V. , Widmeyer W.N. , Brawley L.R.
Published: August 2016

The purpose of this paper was fourfold. The first purpose was to demonstrate the need to develop an instrument to assess group cohesion while the second was to outline a conceptual model of group cohesion upon which such an instrument could be based. This model reflected four related constructs which were the a priori basis for developing a large item pool and initial versions of the Group Environment Questionnaire (GEQ). The third purpose was to outline the four projects conducted to obtain construct-related information and to develop an initial version of the GEQ. The final purpose was to outline the two reliability and validity studies conducted with two different sport team samples. The results of these studies revealed that an 18-item version of the GEQ was internally consistent, reliable across studies, and content valid. Factor analyses with oblique rotation revealed preliminary evidence for construct validity. The GEQ is comprised of four scales reflecting the constructs of group integration-task, group integration-social, individual attractions to group-task, and individual attractions to group-social.
A Prospective View of the Journal of Sport (and Exercise) Psychology
Authors: Gill Diane L.
Published: August 2016

This article has two major purposes, to discuss the general scope and direction of the Journal of Sport Psychology (JSP) and to describe the basic editorial review process. During its first 7 years the journal has developed into the premier scientific publication in sport psychology. The journal will continue to emphasize theoretically based research. Various psychological approaches and research methodologies are appropriate as long as the information advances our understanding of sport and exercise behavior. The typical editorial and review processes are described for the benefit of prospective authors who may wish to become familiar with these standards and procedures before submitting manuscripts to JSP.
Athletic or Antisocial? The Female Sport Experience
Authors: Jackson Susan A. , Marsh Herbert W.
Published: August 2016

The purpose of this study was to examine relations between women's involvment in sports and three psychological constructs: role conflict, sex-role identification, and multidimensional self-concepts. The three groups comprised female powerlifters competing in a national championship (n = 30), high school female athletes (n = 46), and high school female nonathletes (n = 46). Role conflict was not substantial except for a few specific areas related to conflicting expectations of appropriate female and athlete behavior. Both athletic groups scored substantially higher on masculinity (M) and on self-concept of physical ability than the nonathletic group, but there were no group differences on femininity (F) and few substantial differences in other areas of self-concept. Hence the results provide further support for the construct validity of androgyny and for the multidimensionality of self-concept. The major findings, that female athletes can be more M without being less F, and that female athletic involvement has positive benefits without producing any loss in F or in self-concept, dispels a popular myth about women's involvement in sports.
Expert-Novice Differences in an Applied Selective Attention Task
Authors: Abernethy Bruce , Russell David G.
Published: August 2016

Two experiments are described comparing the temporal and spatial characteristics of the anticipatory cues used by expert (n=20) and novice (n=35) racquet sport players. In both experiments the perceptual display available in badminton was simulated using film, and display characteristics were selectively manipulated either by varying the duration of the stroke sequence that was visible (Experiment 1) or by selectively masking specific display features (Experiment 2). The subjects* task in all cases was to predict the landing position of the stroke they were viewing. It was found in Experiment 1 that experts were able to pick up more relevant information from earlier display cues than could novices, and this appeared in Experiment 2 to be due to their ability to extract advance information from the playing side arm, in addition to the racquet itself. These differences, it was concluded, were congruent with predictions that could be derived from traditional information-processing notions related to recognition of display redundancy. The roles of different anticipatory cue sources in the independent predictions of stroke speed and direction were also examined, and it was concluded that directional judgments were more dependent on cue specificity than were depth judgments.
Effects of Continuous Passive Motion Following ACL Reconstruction with Autogenous Patellar Tendon Grafts
Authors: Yates Carlan K. , McCarthy Michael R. , Hirsch Howard S. , Pascale Mark S.
Published: August 2016

This study examined the benefits and possible risks of immediate continuous passive motion after autogenous patellar tendon reconstruction of the anterior cruciate ligament. Thirty patients scheduled to undergo ACL reconstruction were prospectively randomized into two groups, CPM and non-CPM. Postoperatively, those in the non-CPM group wore a hinged knee brace. Those in the CPM group were kept on a CPM machine 16 hrs a day while in the hospital and they used it 6 hrs a day for the first 2 weeks postoperatively. After surgery the patients were assessed for hemovac drainage, range of motion, swelling, effusion, subjective pain, and use of pain medication. The CPM group had significantly less swelling and effusion, required less pain medication, and had greater knee flexion. No differences were found in hemovac drainage, passive knee extension, or subjective pain reports despite a significantly greater use of pain medication in the non-CPM group. The results suggest that immediate CPM after ACL reconstruction is safe and facilitates early range of motion by decreasing the amount of pain medication, effusion, and soft tissue swelling.
Effect of a 4-Week Agility-Training Program on Postural Sway in the Functionally Unstable Ankle
Authors: Hess Damien M. , Joyce Christopher J. , Arnold Brent L. , Gansneder Bruce M.
Published: August 2016

Context:

Agility training has been proposed as an important tool in rehabilitation. However, it is unclear which types of agility training are most useful.

Objective:

To assess the effects of agility training on balance in individuals with functionally unstable ankles.

Design:

A 2-group experimental design with repeated measures.

Setting:

Laboratory.

Patients:

Twenty college-aged volunteers, each with 1 functionally unstable ankle, were randomly assigned to 1 of 2 groups.

Interventions:

Subjects in the experimental group performed agility training 3 times per week for 4 weeks.

Main Outcome Measures:

Subjects were tested for static single-leg balance before and after the training period. Anterior/posterior sway amplitude, medial/lateral sway amplitude, and sway index were assessed using the Chattex Balance System.

Results:

No significant differences in balance were found after the agility training.

Conclusions:

Agility training did not improve static single-leg balance in subjects with functionally unstable ankles.
The Effects of Training the Humeral Rotators on Arm Elevation in the Scapular Plane
Authors: Durall Chris J , Davies George J , Kernozek Thomas W , Gibson Mark H , Fater Dennis CW , Straker J Scott
Published: August 2016

Context:

It has been hypothesized that the fibers of the infraspinatus and subscapularis superior to the glenohumeral axis of rotation contribute directly to arm elevation.

Objective:

To test this hypothesis by assessing the impact of 5 weeks of concentric isokinetic humeral-rotator training in a modified neutral position on scapular-plane arm-elevation peak torque.

Design:

Prospective, pretest/posttest with control group.

Participants:

24 female and 6 male noninjured college students (N = 30).

Main Outcome Measures:

Scapular-plane-elevation peak torque at 60, 180, and 300°/s.

Results:

Repeated-measures ANOVA indicated no difference in peak torque between groups at any of the angular velocities tested (P< .05)

Conclusions:

5 weeks of concentric isokinetic humeral-rotator training did not significantly increase scapular-plane-elevation peak torque.
Relationship between Closed-Linear-Kinetic-and Open-Kinetic-Chain Isokinetic Strength and Lower Extremity Functional Performance
Authors: Kovaleski John E. , Heitman Robert J. , Andrew Damon P.S. , Gurchiek Larry R. , Pearsall Albert W.
Published: August 2016

Context:

Isokinetic strength and functional performance are used to assess recovery after rehabilitation. It is not known whether low-speed closed-linear-kinetic isokinetic muscle strength correlates with functional performance.

Objective:

To investigate the relationship between linear closed (CKC) and open (OKC) concentric isokinetic strength of the dominant lower-limb extensors and functional performance.

Design:

Correlational analysis.

Setting:

University laboratory.

Participants:

Thirty uninjured men and women (age = 20.9 ± 2.4 years).

Main Outcome Measures:

Peak CKC and OKC isokinetic strength and best score from a shuttle run for time, single-leg vertical jump, and single-leg hop for distance.

Results:

Neither lower-limb CKC nor OKC isokinetic strength measured at low speeds correlated highly with performance on the functional tasks of jumping, hopping, and speed/agility.

Conclusions:

Although the basis of both closed and open isokinetic strength must be appreciated, they should not be the only determinants of functional performance.
Effect of Gallium-Aluminum-Arsenide Triple-Diode Laser Irradiation on Evoked Motor and Sensory Action Potentials of the Median Nerve
Authors: Bartlett William P. , Quillen William S. , Greer Rebbeca G.
Published: August 2016

Purpose:

to measure the effects of gallium-aluminum-arsenide (GaAlAs) triple-diode laser irradiation (830 nm, 90 mW) on neural transmission in the median nerve and to determine whether location of treatment influences effectiveness of treatment.

Participants:

42 healthy, adult volunteers, each assigned to 1 GaAlAs or placebo laser group and 1 wrist or forearm treatment group under randomized, double-blinded conditions.

Method:

Nerve-conduction studies were performed on each subject’s nondominant arm before and 10 minutes after treatment. Peak-to-peak amplitudes of both evoked motor and sensory action potentials (APs) were recorded.

Results:

A 2-way ANOVA indicated no significant differences among the amplitudes associated with placebo and GaAlAs laser irradiation. Amplitudes of sensory APs associated with location (wrist or forearm) were, however, significantly different both before and after treatment. No significant interaction was observed between laser and location after treatment, indicating that GaAlAs laser irradiation did not affect median-nerve APs.
Center-of-Pressure Parameters Used in the Assessment of Postural Control
Authors: Palmieri Riann M. , Ingersoll Christopher D. , Stone Marcus B. , Krause B. Andrew
Published: August 2016

Objective:

To define the numerous center-of-pressure derivatives used in the assessment of postural control and discuss what value each might provide in the assessment of balance.

Data Sources:

MEDLINE and SPORTDiscus were searched with the termsbalance, postural control, postural sway,andcenter of pressure. The remaining citations were collected from references of similar papers. A total of 67 references were studied.

Conclusions:

Understanding what is represented by each parameter used to assess postural control is crucial. At the present time the literature has failed to demonstrate how the variables reflect changes made by the postural-control system. Until it can be shown that the center of pressure and its derivatives actually reveal changes in the postural-control system, the value of using these measures to assess deficits in postural control is minimized.
The Effect of Functional Training on the Incidence of Shoulder Pain and Strength in Intercollegiate Swimmers
Authors: Swanik Kathleen A. , Swanik C. Buz , Lephart Scott M. , Huxel Kellie
Published: August 2016

Objective:

To determine whether functional training reduces the incidence of shoulder pain and increases strength in intercollegiate swimmers.

Design:

Pretest–posttest.

Setting:

Laboratory and weight room.

Participants:

26 intercollegiate swimmers (13 men, 13 women).

Intervention:

6-wk functional training program.

Main Outcome Measures:

Incidence of shoulder pain was recorded throughout the study. Isokinetic shoulder strength was assessed before and after training.

Results:

A t test showed significant differences (P < .05) for the incidence of shoulder pain between the experimental (mean episodes = 1.8 ± 2.1) and control (mean episodes = 4.6 ± 4.7) groups. ANOVA with repeated measures revealed no significant strength differences between groups but exhibited significant within-group increases.

Conclusions:

Incorporating functional exercises might reduce incidence of shoulder pain in swimmers. The results also validate the need to modify preventive programs as the demands of the sport change throughout the season.
Characteristics of Shoulder-Position Sense: Effects of Mode of Movement, Scapular Support, and Arm Orientation
Authors: Janwantanakul Prawit , Jones Mark A. , Magarey Mary E. , Miles Timothy S.
Published: August 2016

Context:

Although the repositioning test is widely used to evaluate proprioception, the effects of several test-associated variables on the test outcome are not known.

Objective:

To determine the effects of mode of movement, scapular support, and arm orientation on shoulder-position sense.

Participants:

49 healthy, randomly selected men.

Methods:

The repositioning test was conducted in 4 settings in which mode of movement, scapular support, and arm orientation were manipulated differently.

Main Outcome Measure:

Position-sense acuity was quantified as repositioning accuracy and consistency.

Results:

Active limb movement significantly enhanced repositioning accuracy and consistency compared with passive movement. Repositioning consistency was significantly better when the scapula was supported than when it was not. Arm orientation had no significant effect on repositioning accuracy and consistency.

Conclusion:

The protocol for evaluating or rehabilitating shoulder proprioception should include active limb movement with the scapula unsupported to ensure that it refects a patient’s proprioceptive demand during functional activities.
Comparisons of Land-Based and Aquatic-Based Plyometric Programs during an 8-Week Training Period
Authors: Miller Michael G. , Berry David C. , Bullard Susan , Gilders Roger
Published: August 2016

Context:

Land and aquatic plyometrics have clinical relevance for exercise, sport performance, and rehabilitation, yet study is limited comparing both.

Objective:

To compare the effects of land-based and aquatic-based plyometric-training programs on performance variables, muscle soreness, and range of motion (ROM).

Setting:

Aquatic facility and biomechanics laboratory.

Subjects:

Forty subjects randomly assigned to 3 groups: land (n = 13), water (n = 13), and control (n = 14).

Main Outcome Measures:

Performance variables, muscle soreness, and ROM were measured before and after an 8-week training period. An analysis of covariance (ANCOVA) and a Bonferroni post hoc test determined significance.

Results:

ANCOVA revealed significant differences between groups with respect to plantar-flexion ROM (P < .05). Paired t test determined that the aquatic group significantly increased muscle power pretest to posttest (P < .05).

Conclusions:

Results indicate that aquatic plyometric training can be an alternative approach to enhancing performance.
A Preliminary Investigation into the Use of Counseling Skills in Support of Rehabilitation from Sport Injury
Authors: Rock Judith A. , Jones Marc V.
Published: August 2016

Objectives:

To explore the usefulness of counseling skills for 3 athletes undergoing rehabilitation from anterior-cruciate-ligament-reconstruction surgery.

Design:

A series of 3 case studies explored the impact of a counseling-skills intervention over 12 weeks postsurgery. Semistructured interviews were conducted 12 weeks postsurgery for triangulation and social validation of intervention.

Participants:

3 athletes meeting selection criteria, recruited from a hospital waiting list and receiving standardized rehabilitation regime.

Intervention:

Participants each received 6 counseling skills interventions at 2-week intervals.

Main Outcome Measures:

Mood, perceived rehabilitation, pain ratings, social support.

Results:

Triangulation of interview data and outcome measures provided some evidence of the beneficial impact of counseling skills on psychological outcomes. It also indicated that setbacks could present challenges to rehabilitation.

Conclusions:

Counseling skills can enhance psychological well-being of athletes during rehabilitation and be especially important during setbacks.
Acute and Chronic Tendon Injuries: Factors Affecting the Healing Response and Treatment
Authors: Sandrey Michelle A.
Published: August 2016

Objective:

Tendons have biomechanical properties based on collaborative remodeling of all their cells through normal lysis and synthesis. This review assesses factors that affect the healing response and presents solutions for rehabilitating acute and chronic tendon injuries.

Data Sources:

MEDLINE (1970–2002) and SPORTDiscus (1970–2002). Key words searched weretendon, tendinitis, tendinosis, tendinopathy, rehabilitation, ultrasound, NSAIDs, exercise, mobilization, aging, immobilization,andhealing.

Data Synthesis:

The biomechanical roles tendons play change throughout one’s lifetime and are influenced by maturation and aging, injury and healing, immobilization, exercise, medications, and therapeutic modalities. Suggestions from animal, case, and clinical studies are varied but provide solutions in the treatment of acute and chronic tendon injuries.

Conclusions and Recommendations:

All factors that affect the tendon structure should be considered in a rehabilitation program. Therapeutic exercise, medications, or therapeutic modalities should never be used as a stand-alone therapy.
Influence of Foot Type and Orthotics on Static and Dynamic Postural Control
Authors: Olmsted Lauren C. , Hertel Jay
Published: August 2016

Context:

The effects of custom-molded foot orthotics on neuromuscular processes are not clearly understood.

Objective:

To examine these effects on postural control in subjects with different foot types.

Design:

Between-groups, repeated-measures design.

Setting:

Athletic training laboratory.

Subjects:

30 healthy subjects assigned to groups by foot type: planus (n = 11), rectus (n = 12), or cavus (n = 7).

Interventions:

Custom-fit semirigid orthotics.

Main Outcome Measures:

Static postural control was measured on a force plate. Dynamic postural control was measured using the Star Excursion Balance Test. Both measurements were assessed with and without orthotics at baseline and 2 weeks later.

Results:

For static postural control, a significant condition-by-group interaction was found. Subjects with cavus feet had a decreased center-of-pressure velocity while wearing orthotics. For dynamic postural control, a significant condition-by-direction-by-group interaction was found. Subjects with cavus feet had increased reach distances in 3 of 8 directions while wearing orthotics.

Conclusions:

Custom orthotics were associated with some improvements in static and dynamic postural control in subjects with cavus feet.
Effects of Lower Extremity Fatigue on Indices of Balance
Authors: Yaggie James , Armstrong W. Jeffrey
Published: August 2016

Context:

Use of selective joints in fatiguing protocols might not represent athletic activity and limits generalizability.

Objective:

To quantify changes in balance indices after a generalized fatiguing activity.

Design:

Repeated measures.

Setting:

Clinical laboratory.

Participants:

16 men (24 ± 3 y) with no orthopedic problems.

Intervention:

Balance was assessed using the KAT-2000 system before (PRE) and immediately (IMMED) and 10 min (10MIN) after serial Wingate tests and at similar time points under nonfatigue conditions.

Main Outcome Measures:

Balance index (BI), fore:back ratio, and right:left ratio.

Results:

MANOVA revealed a significant Condition × Time effect (P = .023). ANOVA revealed that only BI was significant for the condition, time, and Condition × Time effects (P = .020, .007, and .003, respectively). BI increased PRE to IMMED, decreased IMMED to 10MIN, and was different from the nonfatigue condition only for IMMED (P = .002, < .001, and < .001, respectively).

Conclusions:

Fatigue adversely affects BI; recovery might occur within 10 min.
Gluteus Medius Activity during 3 Variations of Isometric Single-Leg Stance
Authors: Earl Jennifer E.
Published: August 2016

Context:

Gluteus medius (GM) contraction during single-leg stance prevents the contralateral pelvis from “dropping,” providing stability for lower extremity motion.

Objective:

To determine which combination of hip rotation and abduction exercise results in the greatest activity of the GM and whether the GM responds to increased loads in these exercises.

Design and Setting:

Repeated measures, laboratory.

Subjects:

20 healthy volunteers.

Interventions:

Resistance (2.26 and 4.53 kg) was provided to 3 variations of a single-leg-stance exercise: hip abduction only, abduction-internal rotation (ABD-IR), and abduction-external rotation.

Measurements:

Muscle activity was recorded from the anterior and middle portions of the GM using surface electromyography.

Results:

ABD-IR produced the most activity in the anterior and middle sections of the GM muscle. The 4.53-kg load produced significantly more activity than the 2.26-kg load (P< .05).

Conclusions:

The GM is most active when performing abduction and internal rotation of the hip. This information could be used to develop GM-strengthening exercises.
What Are the Validity of the Single-Leg-Squat Test and Its Relationship to Hip-Abduction Strength?
Authors: DiMattia Mario A. , Livengood Ann L. , Uhl Tim L. , Mattacola Carl G. , Malone Terry R.
Published: August 2016

Context:

The Trendelenburg and single-leg-squat (SLS) tests are purported measures of hip-abduction strength that have not been previously validated.

Objective:

To correlate isometric hip-abduction strength to frontal-plane hip motion during an SLS and determine the criterion validity of a clinical-observation-analysis method to grade an SLS against 2-dimensional kinematic analysis.

Design:

Single-measure, concurrent validity.

Setting:

Biodynamics research laboratory.

Participants:

50 uninjured participants.

Main Outcome Measures:

Hip-abduction strength and hip and knee kinematic data during a Trendelenburg test and an SLS.

Results:

A weak, positive correlation between hip-abduction strength and hip-adduction angle was found during both the Trendelenburg (r= .22,P= .13) and the SLS (r= .21,P= .14) tests. The observation-analysis method revealed a low sensitivity, .23, and a higher specificity, .86, when compared with the kinematic data.

Conclusion:

The usefulness of the Trendelenburg and SLS test in screening hip-abductor strength in a healthy physically active population is limited. The origin of observable deficits during SLS requires further objective assessment.
The Effects of Calf-Muscle Fatigue on Sagittal-Plane Joint-Position Sense in the Ankle
Authors: Huston Jeffery L. , Sandrey Michelle A. , Lively Mathew W. , Kotsko Kevin
Published: August 2016

Context:

There is limited information on the effect of dynamic fatiguing of the plantar flexors on joint-position sense (JPS).

Objective:

To examine the effects of fatigue on JPS for ankle plantar flexion (PF) and dorsiflexion (DF).

Design:

A 2 × 2 factorial design.

Setting:

Research laboratory.

Participants:

20 healthy subjects (10 men, 10 women; age 21.75 ± 1.48 years).

Interventions:

The subjects were tested at 10° DF and 20° PF in the nonfatigued and fatigued conditions on a custom-built JPS device. To induce fatigue, subjects stood with both feet in the plantar-flexed position until they could no longer hold the posture.

Main Outcome Measures:

JPS absolute error was measured at 10° DF and 20° PF.

Results:

There was no significant main effect for condition, measurement, or interaction between condition and measurement.

Conclusion:

With no difference between conditions, the main controller of conscious JPS of the lower extremity might be the tibialis anterior.
Ground-Reaction Forces during Form Skipping and Running
Authors: Johnson Sam T. , Golden Grace M. , Mercer John A. , Mangus Brent C. , Hoffman Mark A.
Published: August 2016

Context:

Form skipping has been used to help injured athletes progress to running. Because little research has been done on form-skipping mechanics, its justification as a progression to running exercises is unclear.

Objective:

To compare ground-reaction forces (GRF) during form skipping and running in healthy subjects at clinically relevant speeds, 1.75 m/s and 3.83 m/s, respectively.

Design:

Dependent t tests (α = .05).

Setting:

Sports-injury research center.

Participants:

9 male college athletes (age 20 ± 1.33 years, mass 848.4 ± 43.24 N, height 1.80 ± 0.07 m).

Main Outcome Measures:

Average (Fzavg) and maximum (Fzmax) vertical GRF and (Fy) braking impulse were compared.

Results:

Fzavg and Fzmax were greater during running than during form skipping (P < .05). Braking impulses were not different (P > .05).

Conclusions:

It appears that Fz, but not the Fy, GRF might explain why form skipping might be an appropriate progression to running.
Reliability and Precision of in Vivo Scapular Kinematic Measurements Using an Electromagnetic Tracking Device
Authors: Myers Joseph , Jolly John , Nagai Takashi , Lephart Scott
Published: August 2016

Context:

In vivo scapular kinematics during humeral movements are commonly assessed with electromagnetic tracking devices despite few published data related to reliability and precision of these measurements.

Objective:

To determine the intrasession reliability and precision of assessing scapular kinematics using an electromagnetic tracking device.

Design:

Scapular position and orientation were measured with an electromagnetic tracking device during humeral elevation/depression in several planes. Intrasession reliability and precision were established by comparing 2 trials performed in succession.

Setting:

A human-movement research laboratory.

Participants:

15 healthy individuals.

Main Outcome Measures:

Intrasession intraclass correlation coefficients and standard error of measurement of all scapular variables were established.

Results:

The mean intrasession reliability for all variables was ICC = .97 ± .03. The mean intrasession precision was .99° ± .36°.

Conclusions:

In vivo scapular kinematics can be measured with high reliability and precision during intrasession research designs.
The Relationship between Lower Extremity Isokinetic Work and Single-Leg Functional Hop-Work Test
Authors: English Robert , Brannock Mary , Chik Wan Ting , Eastwood Laura S. , Uhl Tim
Published: August 2016

Context:

Lower extremity functional testing assesses strength, power, and neuro-muscular control. There are only moderate correlations between distance hopped and isokinetic strength measures.

Objective:

Determine if incorporating body weight in the single-leg hop for distance increases the correlation to isokinetic measures.

Study Design:

Correlational study.

Setting:

Musculoskeletal laboratory.

Participants:

30 healthy college students; 15 men and 15 women; ages 18 to 30 years.

Main Outcome Measures:

Isokinetic average peak torque and total work of quadriceps and hamstrings and single-leg hop work and distance.

Results:

Significant correlations include hop work to total-work knee extension (r= .89), average peak-torque knee extension (r= .88), distance hopped to total-work knee extension (r= .56) and average peak-torque knee extension (r= .63). Correlations involving hop work were greater than distance hopped (P< .05).

Conclusions:

Use of body weight in the assessment of distance hopped provides better information about the patient’s lower extremity strength and ability than the distance hopped alone.
Predisposing Risk Factors on Susceptibility to Exertional Heat Illness: Clinical Decision-Making Considerations
Authors: Cleary Michelle
Published: August 2016

Objective:

To present strategies for identifying predisposing conditions, susceptibility, and incidence reduction for the most common exertional heat illnesses (EHI): heat cramps, heat exhaustion, and most importantly, heat stroke.

Data Sources:

A comprehensive literature review of MEDLINE and 1996 to 2006, including all retrospective, controlled studies of EHI risk using the following keywords: exertional heat illness risk, exertional heat stroke risk, and exercise-induced dehydration risk. Search limits included the following: English language, published in the last 10 years, clinical trial, meta-analysis, practice guideline, randomized controlled trial, review, and humans. A manual review was conducted of relevant position statements and book chapters including the reference lists.

Data Extraction:

To evaluate the quality of the empirical studies to be included in this review, each study must have scored at least 17/22 or 77% of items included when reporting a randomized trial using the CONSORT checklist.

Data Synthesis:

Many cases of EHI are preventable and can be successfully treated if the ATC® identifies individuals at increased relative risk and implement appropriate prevention strategies. The ability to objectively identify individuals at increased relative risk of EHI and to provide appropriate monitoring is critical in EHI prevention and reduction of repeated incidents of EHI.

Conclusions:

For any heat illness prevention program to be effective, greater attention and continued observation is needed for athletes at high risk for EHI. For many athletic teams or programs, because of the sheer numbers and associated catastrophic injury potential, health care professionals must implement a system by which high-risk individuals are monitored during activity with the highest level of vigilance for prevention of EHI.
The Heat Tolerance Test: An Efficient Screening Tool for Evaluating Susceptibility to Heat
Authors: Moran Daniel S. , Erlich Tomer , Epstein Yoram
Published: August 2016

Context:

Individuals in the population who are not able to sustain heat and whose body temperature will start rising earlier and at a higher rate than that of others, under the same conditions, are defined as “heat intolerant.”

Objectives:

The applicability of the heat tolerance test (HTT) in identifying individuals’ tolerance/intolerance to heat is presented.

Setting:

HTT is performed according to the following protocol: 120 minutes exposure to 40°C and 40% relative humidity in a climatic chamber while walking on a treadmill, dressed in shorts and T-shirt, at a pace of 5 km/h and 2% elevation. Rectal temperature and heart rate are continuously monitored, and sweat rate is calculated.

Results and Conclusion:

The HTT that is based on controlled exposure to an exercise-heat stress is an applicable and an efficient tool in differentiating between a temporary and permanent state of heat susceptibility.
Identification of Risk Factors for Exertional Heat Illness: A Brief Commentary on Genetic Testing
Authors: Muldoon Sheila , Bunger Rolf , Deuster Patricia , Sambuughin Nyamkhishig
Published: August 2016

Objective:

This commentary discusses known links between Exertional Heat Illness (EHI), Malignant Hyperthermia (MH), and other hereditary diseases of muscle. Genetic and functional testing is also evaluated as measures of fitness to return to duty/play.

Data Sources:

Reviews and research articles from Sports Medicine, Applied Physiology, and Anesthesiology.

Data Extraction:

Detailed comparisons of existing literature regarding clinical cases of EHI and MH and the potential utility of genetic testing, specifically the ryanodine receptor (RYR1) gene and other genes related to disorders of skeletal muscle.

Data Synthesis:

EHI is a complex disorder wherein physiological, environmental, and hereditary factors interact to endanger an individual’s ability to maintain thermal homeostasis.

Conclusions:

Individuals’ genetic background is likely to play an important role, particularly when EHI recurs. Recurrent EHI has been associated with MH and other genetic disorders, highlighting the importance of identification and exclusion of individuals with known high risk factors.
Dehydration, Cramping, and Exertional Rhabdomyolysis: A Case Report with Suggestions for Recovery
Authors: Cleary Michelle , Ruiz Daniel , Eberman Lindsey , Mitchell Israel , Binkley Helen
Published: August 2016

Objective:

We present a case of severe dehydration, muscle cramping, and rhabdomyolysis in a high school football player followed by a suggested program for gradual return to play.

Background:

A 16-year-old male football player (body mass = 69.1 kg, height = 175.3 cm) reported to the ATC after the morning session on the second day of two-a-days complaining of severe muscle cramping.

Differential Diagnosis:

The initial assessment included severe dehydration and exercise-induced muscle cramps. The differential diagnosis was severe dehydration, exertional rhabdomyolysis, or myositis. CK testing revealed elevated levels indicating mild rhabdomyolysis.

Treatment:

The emergency department administered 8 L of intravenous (IV) fluid within the 48-hr hospitalization period, followed by gradual return to activity.

Uniqueness:

To our knowledge, no reports of exertional rhabdomyolysis in an adolescent football player exist. In this case, a high school quarterback with a previous history of heat-related cramping succumbed to severe dehydration and exertional rhabdomyolysis during noncontact preseason practice. We provide suggestions for return to activity following exertional rhabdomyolysis.
The Effects of Eversion Fatigue on Frontal Plane Joint Position Sense in the Ankle
Authors: Sandrey Michelle A. , Kent Timothy E.
Published: August 2016

Context:

There is limited information on fatigue of the evertors on frontal plane joint position sense (JPS).

Objective:

To examine the effects of isokinetic concentric-eccentric fatigue of the evertors on frontal plane JPS of the ankle.

Design:

A 2 × 4 factorial design.

Setting:

Research Laboratory.

Patients or Other Participants:

40 male and female healthy subjects.

Interventions:

JPS was tested at 10° and 20° of inversion and 5° and 10° of eversion in a nonfatigued/fatigued condition. After fatigue of evertors was determined on an isokinetic device, post fatigue testing of JPS occurred.

Main Outcome Measures:

JPS absolute error (AE) for inversion and eversion.

Results:

Main effect for condition and angle were significant with pre/post fatigue. There were overestimation of angles postfatigue with AE greater at 20° of inversion (P = .003), followed by 10° of inversion (P < .001), 10° of eversion (P = .005), and 5° of eversion (P = .005).

Conclusion:

When the ankle evertors were fatigued, the AE for JPS was significantly higher at all test angles.
Relationships between Knee Valgus, Hip-Muscle Strength, and Hip-Muscle Recruitment during a Single-Limb Step-Down
Authors: Hollman John H. , Ginos Barbara E. , Kozuchowski Jakub , Vaughn Amanda S. , Krause David A. , Youdas James W.
Published: August 2016

Context:

Reduced strength and activation of hip muscles might correlate with increased weight-bearing knee valgus.

Objective:

To describe relationships among frontal-plane hip and knee angles, hip-muscle strength, and electromyographic (EMG) recruitment in women during a step-down.

Design:

Exploratory study.

Setting:

Laboratory.

Participants:

20 healthy women 20 to 30 years of age.

Interventions:

Frontal-plane hip and knee angles were measured. Gluteus maximus and medius recruitment were examined with surface EMG. Hip-abduction and -external-rotation strength were quantified with handheld dynamometry.

Main Outcome Measurements:

The authors analyzed correlation coefficients between knee and hip angles, gluteus maximus and medius EMG, and hip-abduction and -external-rotation strength.

Results:

Hip-adduction angles (r = .755, P = .001), gluteus maximus EMG (r = −.451, P = .026), and hip-abduction strength (r = .455, P = .022) correlated with frontal-plane projections of knee valgus.

Conclusions:

Gluteus maximus recruitment might have greater association with reduced knee valgus in women than does external-rotation strength during step-down tasks. Gluteus medius strength might be associated with increased knee valgus.
The Hip’s Influence on Low Back Pain: A Distal Link to a Proximal Problem
Authors: Reiman Michael P. , Weisbach P. Cody , Glynn Paul E.
Published: August 2016

Low back pain (LBP) is a multifactorial dysfunction, with one of the potential contributing factors being the hip joint. Currently, research investigating the examination and conservative treatment of LBP has focused primarily on the lumbar spine. The objective of this clinical commentary is to discuss the potential link between hip impairments and LBP using current best evidence and the concept of regional interdependence as tools to guide decision making and offer ideas for future research.
Psychological Benefits of Virtual Reality for Patients in Rehabilitation Therapy
Authors: Chen Chih-Hung , Jeng Ming-Chang , Fung Chin-Ping , Doong Ji-Liang , Chuang Tien-Yow
Published: August 2016

Context:

Whether virtual rehabilitation is beneficial has not been determined.

Objective:

To investigate the psychological benefits of virtual reality in rehabilitation.

Design:

An experimental group underwent therapy with a virtual-reality-based exercise bike, and a control group underwent the therapy without virtual-reality equipment.

Setting:

Hospital laboratory.

Patients:

30 patients suffering from spinal-cord injury.

Intervention:

A designed rehabilitation therapy.

Main Outcome Measures:

Endurance, Borg's rating-of-perceived-exertion scale, the Activation–Deactivation Adjective Check List (AD-ACL), and the Simulator Sickness Questionnaire.

Results:

The differences between the experimental and control groups were significant for AD-ACL calmness and tension.

Conclusion:

A virtual-reality-based rehabilitation program can ease patients' tension and induce calm.
Altered Ankle Kinematics and Shank-Rear-Foot Coupling in Those with Chronic Ankle Instability
Authors: Drewes Lindsay K. , McKeon Patrick O. , Paolini Gabriele , Riley Patrick , Kerrigan D. Casey , Ingersoll Christopher D. , Hertel Jay
Published: August 2016

Context:

Kinematic patterns during gait have not been extensively studied in relation to chronic ankle instability (CAI).

Objective:

To determine whether individuals with CAI demonstrate altered ankle kinematics and shank-rear-foot coupling compared with controls during walking and jogging.

Design:

Case control.

Setting:

Motion-analysis laboratory.

Participants:

7 participants (3 men, 4 women) suffering from CAI (age 24.6 ± 4.2 y, height 172.6 ± 9.4 cm, mass 70.9 ± 8.1 kg) and 7 (3 men, 4 women) healthy, matched controls (age 24.7 ± 4.5 y, height 168.2 ± 5.9 cm, mass 66.5 ± 9.8 kg).

Interventions:

Subjects walked and jogged on a treadmill while 3-dimensional kinematics of the lower extremities were captured.

Main Outcome Measures:

The positions of rear-foot inversion–eversion and shank rotation were calculated throughout the gait cycle. Continuous relative-phase angles between these segments were calculated to assess coupling.

Results:

The CAI group demonstrated more rear-foot inversion and shank external rotation during walking and jogging. There were differences between groups in shank-rear-foot coupling during terminal swing at both speeds.

Conclusions:

Altered ankle kinematics and joint coupling during the terminal-swing phase of gait may predispose a population with CAI to ankle-inversion injuries. Less coordinated movement during gait may be an indication of altered neuromuscular recruitment of the musculature surrounding the ankle as the foot is being positioned for initial contact.
Reliability of the Anterior Drawer and Talar Tilt Tests Using the Ligmaster Joint Arthrometer
Authors: Docherty Carrie L. , Rybak-Webb Katherine
Published: August 2016

Context:

Joint arthrometers have been developed to help determine the severity of ligament sprains.

Objective:

To establish intratester and intertester reliability of the talar inversion and anterior drawer tests using the LigMaster.

Design:

Intratester reliability was investigated using a repeated-measures design. Intertester reliability was investigated using 2 different clinicians testing subjects on the same day.

Setting:

Athletic training research laboratory. Participants: Thirty participants volunteered for this study.

Main Outcome Measurements:

Anterior displacement and talar inversion were measured using the LigMaster.

Results:

Intrarater reliability was .74 for the talar inversion test and .65 for the anterior drawer test. Interrater reliabilities for the talar inversion and anterior drawer tests were .76 and .81, respectively.

Conclusions:

The LigMaster joint arthrometer is a reliable tool for measuring talar inversion and anterior displacement at the ankle.
Intramuscular Pressure, Tissue Oxygenation, and Muscle Fatigue of the Multifidus during Isometric Extension in Elite Rowers with Low Back Pain
Authors: Dehner Christoph , Schmelz Andreas , Völker Hans-Ullrich , Pressmar Jochen , Elbel Martin , Kramer Michael
Published: August 2016

Context:

Chronic low back pain (LBP) has been reported with a high incidence in elite rowers. It results in less effective training, long interruptions in training, and a drop in performance.

Objective:

The authors hypothesized that exercise-induced LBP in rowers is caused by a chronic functional compartment syndrome (CFCS) of the multifidus muscle.

Design:

Controlled clinical trial.

Setting:

The rowers were tested in their training camp. The control group was tested at a university hospital.

Participants:

14 volunteer elite rowers complaining of LBP and 16 healthy volunteer amateur athletes.

Main Outcome Measurements:

Intramuscular pressure (IMP), tissue oxygenation pressure (pO2), and median frequency (MF) shift in the electromyographic power density spectrum during isometric fatiguing extension at 60% of maximum voluntary contraction.

Results:

At the beginning (controls 186.6 mm Hg vs rowers 60.2 mm Hg, P = .002) and the end (controls 224.1 mm HG vs rowers 77.1 mm Hg, P < .001) of the endurance exercise the median IMP was significantly higher in the healthy controls. Nearly identical resting pO2 was measured in both groups (controls 37.6 mm Hg vs rowers 37.3 mm Hg, P = .740). Rowers showed higher median MF shift (rowers −11.5 Hz vs controls −8.5 Hz, P = .079) during contraction.

Conclusions:

These observations cannot sufficiently be explained by the CFCS model and suggest that factors other than IMP have an additional effect on pain generation during exercise in elite rowers.
The Effect of 3 Foot Pads on Plantar Pressure of Pes Planus Foot Type
Authors: Nordsiden Lacey , Van Lunen Bonnie L. , Walker Martha L. , Cortes Nelson , Pasquale Maria , Onate James A.
Published: August 2016

Context:

Many styles of foot pads are commonly applied to reduce immediate pain and pressure under the foot.

Objective:

To examine the effect of 3 different foot pads on peak plantar pressure (PPP) and mean plantar pressure (MPP) under the first metatarsophalangeal joint (MTPJ) during slow running.

Design:

A 4 (pad) × 4 (mask) repeated-measures design.

Setting:

University athletic training clinic and fitness facility.

Participants:

20 physically active participants, 12 men (19.7 ± 1.3 y, 181.5 ± 6.3 cm, 83.6 ± 12.3 kg) and 8 women (20.8 ± 1.5 y, 172.7 ± 11.2 cm, 69.9 ± 14.2 kg) with navicular drop greater than or equal to 10 mm, no history of surgery to the lower extremity, and no history of pain or injury to the first MTPJ in the past 6 months.

Interventions:

PPP and MPP were evaluated under 4 areas of the foot: the rear foot, lateral forefoot, medial forefoot, and first MTPJ. Four pad conditions (no pad, metatarsal dome, U-shaped pad, and donut-shaped pad) were evaluated during slow running. All measurements were taken on a standardized treadmill using the Pedar in-shoe pressure-measurement system.

Main Outcome Measures:

PPP and MPP in 4 designated foot masks during slow running.

Results:

The metatarsal dome produced significant decreases in MPP (163.07 ± 49.46) and PPP (228.73 ± 63.41) when compared with no pad (P < .001). The U-shaped pad significantly decreased MPP (168.68 ± 50.26) when compared with no pad (P < .001). The donut-shaped pad increased PPP compared with no pad (P < .001).

Conclusions:

The metatarsal dome was most effective in reducing both peak and mean plantar pressure. Other factors such as pad comfort, type of activity, and material availability must also be considered. Further research should be conducted on the applicability to other foot types and symptomatic subjects.
Influence of Hip Position on Electromyographic and Torque Productions in the Knee
Authors: Black Scott J. , Woodhouse Michael L. , Suttmiller Stephen , Shall Larry
Published: August 2016

The effects of hip position on thigh electromyographic (EMG) activity and knee torque were evaluated. Twenty-four recreational athletes (12 males and 12 females) volunteered to participate. Subjects were tested isokinetically at 30°/s in sitting and supine positions both concentrically and eccentrically during knee flexion and extension. Gravity-corrected torques (N·m) were obtained for all tests. EMG amplitude (mV) was collected via surface electrodes. Torque values were significantly greater (p<.05) for knee flexion in the sitting position when compared to the supine. EMG activity did not change relative to hip position but typically increased (p<.05) during concentric trials. Knee extension torque and EMG activity did not change during sitting or supine positions. Results indicated that the sitting position had statistically significant advantages over the supine position for producing greater hamstring torque and maintaining similar levels of EMG output during isokinetic knee flexion.