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Aims: The American Academy of Pediatrics recommends “parents to incorporate supervised, awake ‘prone play’ in their infant’s routine to support motor development and minimize the risk of plagiocephaly”. The purpose of this feasibility study was to compare usual care to a reward contingency–based intervention, developed to increase prone tolerance and improve motor skills. Methods: Ten full-term infants, 3–6- months old, with poor prone tolerance were randomized to either the Education group or Reward contingency group. Each group participated in three parent education sessions and 15 intervention sessions, over the period of three weeks. Infants in the Reward contingency group used the Prone Play Activity Center, a technology developed to reinforce motor behavior of infants in prone position. Intervention frequency and parent feedback data determined the feasibility of the interventions. Results: Infants in the Reward contingency group practiced a median of 12 of the 15 anticipated intervention sessions in the Prone Play Activity Center. These infants used the device for a mean of 18 minutes per day. Parents of infants in the Education group practiced a median of 10 sessions of the 15 anticipated intervention sessions. Conclusion: The reward contingency–based intervention is feasible for use in a future clinical trial with some modifications.

Background Complex movement pathologies that are biopsychosocial in nature (eg, back pain) require a multidimensional approach for effective treatment. Virtual reality is a promising tool for rehabilitation, where therapeutic interventions can be gamified to promote and train specific movement behaviors while increasing enjoyment, engagement, and retention. We have previously created virtual reality–based tools to assess and promote lumbar excursion during reaching and functional gameplay tasks by manipulating the position of static and dynamic contact targets. Based on the framework of graded exposure rehabilitation, we have created a new virtual reality therapy aimed to alter movement speed while retaining the movement-promoting features of our other developments. Objective This study aims to compare lumbar flexion excursion and velocity across our previous and newly developed virtual reality tools in a healthy control cohort. Methods A total of 31 healthy participants (16 males, 15 females) took part in 3 gamified virtual reality therapies (ie, Reachality, Fishality, and Dodgeality), while whole-body 3D kinematics were collected at 100 Hz using a 14-camera motion capture system. Lumbar excursion, lumbar flexion velocity, and actual target impact location in the anterior and vertical direction were compared across each virtual reality task and between the 4 anthropometrically defined intended target impact locations using separate 2-way repeated measures analysis of variance models. Results There was an interaction between game and impact height for each outcome (all P Conclusions Lumbar flexion velocity was reduced during Fishality relative to that during Dodgeality and resembled velocity demands more similar to those for a self-paced reaching task (ie, Reachality). Additionally, lumbar motion and target impact location during Fishality were more similar to those during Reachality than to those during Dodgeality, which suggests that this new virtual reality game is an effective tool for shaping movement. These findings are encouraging for future research aimed at developing an individualized and graded virtual reality intervention for patients with low back pain and a high fear of movement.

Background Associative learning is the ability to discover a relationship between two or more events. We combined principles of learning and technology to develop a paradigm to assess associative learning in prone. Purpose The purpose of this study was to determine whether 3- to 6-month-old infants can demonstrate: (1) short-term learning of an association between their upper body movements in prone and activation of a toy, and (2) retention of the association learned on day 1, 24 hours later. Methods Twenty-eight infants who were 3 to 6 months of age and who were typically developing were tested for 2 consecutive days in an instrumented play gym. Both days of testing had a baseline and 4 acquisition phases (2 minutes each). During the acquisition phase, the toy activated for a maximum of 10 seconds when the infant's head was above a threshold. A criterion was set a priori to distinguish infants as short-term learners and retainers of the association learned on day 1. Results Of 28 infants, 22 and 14 infants completed all phases of the testing on day 1 and day 2, respectively. Fourteen (50%) of the infants met the criteria for short-term learners. On day 2, there was an analyzable sample of 9 short-term learners. Three of the 12 short-term learners (25%) demonstrated retention on day 2. Conclusion Consistent with prior infant motor learning research, half of the infants demonstrated associative learning in this novel assessment in prone; however, based on study criteria, the infants had limited retention of the association on day 2.

The Academy of Pediatric Physical Therapy Research Summit IV issued a Call to Action for community-wide intensification of a research enterprise in inquiries related to pediatric brain injury and motor disability by way of technological integration. But the barriers can seem high, and the pathways to integrative clinical research can seem poorly marked. Here, we answer the Call by providing framework to 3 objectives: (1) instrumentation, (2) biometrics and study design, and (3) data analytics. We identify emergent cases where this Call has been answered and advocate for others to echo the Call both in highly visible physical therapy venues and in forums where the audience is diverse.

Context:Chronic ankle instability (CAI) is characterized by repeated ankle sprains, which have been linked to postural instability. Therefore, it is important for clinicians to identify individuals with CAI who can benefit from rehabilitation.Objective:To assess the likelihood that CAI participants will exhibit impaired postural stability and that healthy control participants will exhibit better test performance values.Design:Case-control study.Setting:Laboratory.Patients or Other Participants:People with CAI (n = 17, age = 23 ± 4 years, height = 168 ± 9 cm, weight = 68 ± 12 kg) who reported ankle “giving-way” sensations and healthy volunteers (n = 17, age = 23 ± 3 years, height = 168 ± 8 cm, weight = 66 ± 12 kg).Intervention(s):Participants performed 7 balance tests: Balance Error Scoring System (BESS), time in balance, foot lift, single-legged stance on a force plate, Star Excursion Balance Test, side hop, and figure-of-8 hop.Main Outcome Measure(s):Balance was quantified with errors (score) for the BESS, length of time balancing (seconds) for time-in-balance test, frequency of foot lifts (score) for foot-lift test, velocity (cm/s) for all center-of-pressure velocity measures, excursion (cm) for center-of-pressure excursion measures, area (cm2) for 95% confidence ellipse center-of-pressure area and center-of-pressure rectangular area, time (seconds) for anterior-posterior and medial-lateral time-to-boundary (TTB) measures, distance reached (cm) for Star Excursion Balance Test, and time (seconds) to complete side-hop and figure-of-8 hop tests. We calculated area-under-the-curve values and cutoff scores and used the odds ratio to determine if those with and without CAI could be distinguished using cutoff scores.Results:We found significant area-under-the-curve values for 4 static noninstrumented measures, 3 force-plate measures, and 3 functional measures. Significant cutoff scores were noted for the time-in-balance test (≤25.89 seconds), foot-lift test (≥5), single-legged stance on the firm surface (≥3 errors) and total (≥14 errors) on the BESS, center-of-pressure resultant velocity (≥1.56 cm/s), standard deviations for medial-lateral (≤1.56 seconds) time-to-boundary and anterior-posterior (≤3.78 seconds) time-to-boundary test, posteromedial direction on the Star Excursion Balance Test (≤0.91), side-hop test (≥12.88 seconds), and figure-of-8 hop test (≥17.36 seconds).Conclusions:Clinicians can use any of the 10 significant measures with their associated cutoff scores to identify those who could benefit from rehabilitation that reestablishes postural stability.

Context: Why some individuals with ankle sprains develop functional ankle instability and others do not (ie, copers) is unknown. Current understanding of the clinical profile of copers is limited. Objective: To contrast individuals with functional ankle instability (FAI), copers, and uninjured individuals on both self-reported variables and clinical examination findings. Design: Cross-sectional study. Setting: Sports medicine research laboratory. Patients or Other Participants: Participants consisted of 23 individuals with a history of 1 or more ankle sprains and at least 2 episodes of giving way in the past year (FAI: Cumberland Ankle Instability Tool [CAIT] score = 20.52 ± 2.94, episodes of giving way = 5.8 ± 8.4 per month), 23 individuals with a history of a single ankle sprain and no subsequent episodes of instability (copers: CAIT score = 27.74 ± 1.69), and 23 individuals with no history of ankle sprain and no instability (uninjured: CAIT score = 28.78 ± 1.78). Intervention(s): Self-reported disability was recorded using the CAIT and Foot and Ankle Ability Measure for Activities of Daily Living and for Sports. On clinical examination, ligamentous laxity and tenderness, range of motion (ROM), and pain at end ROM were recorded. Main Outcome Measure(s): Questionnaire scores for the CAIT, Foot and Ankle Ability Measure for Activities of Daily Living and for Sports, ankle inversion and anterior drawer laxity scores, pain with palpation of the lateral ligaments, ankle ROM, and pain at end ROM. Results: Individuals with FAI had greater self-reported disability for all measures (P < .05). On clinical examination, individuals with FAI were more likely to have greater talar tilt laxity, pain with inversion, and limited sagittal-plane ROM than copers (P < .05). Conclusions: Differences in both self-reported disability and clinical examination variables distinguished individuals with FAI from copers at least 1 year after injury. Whether the deficits could be detected immediately postinjury to prospectively identify potential copers is unknown.

Background and Purpose. Scapular muscle performance evaluated with a handheld dynamometer (HHD) has been investigated only in people without shoulder dysfunction for test-retest reliability of data obtained with a single scapular muscle test. The purpose of this study was to assess the reliability, error, and validity of data obtained with an HHD for 4 scapular muscle tests in subjects with shoulder pain and functional loss. Subjects and Methods. Subjects (N=40) with shoulder pain and functional loss were tested bymeasuring the kilograms applied with an HHD during 3 trials for muscle tests for the lower trapezius, upper trapezius, middle trapezius, and serratus anterior muscles. Concurrently, surface electromyography (sEMG) data were collected for the 4 muscles. The same procedures were performed 24 to 72 hours after the initial testing by the same tester. Muscle tests were performed 3 times, and the results were averaged for data analysis. Results. Intraclass correlation coefficients for intratester reliability of measurements of isometricforce obtained using an HHD ranged from .89 to .96. The standard error of the measure (90% confidenceinterval [CI]) ranged from 1.3 to 2.7 kg; the minimal detectable change (90% CI) ranged from 1.8 to 3.6 kg. Construct validity assessment, done by comparing the amounts of isometric muscle activity (sEMG) for each muscle across the 4 muscle tests, revealed that the muscle activity of the upper trapezius and lower trapezius muscles washighest during their respective tests. Conversely, the isometric muscle activity of the middle trapezius and serratus anterior muscles was not highest during their respective tests. Discussion and Conclusion. In people with shoulder pain and functional loss, the intrarater reliability and error over 1 to 3 days were established using an HHD for measurement of isometric force for the assessment of scapular muscle performance. Error values can be used to make decisions regarding individual patients. Construct validity was established for the lower and upper trapezius muscle tests; therefore, these tests are advocated for use. However, construct validity was not demonstrated for the serratus anterior and middle trapezius muscle tests as performed in this study. Further investigation of these muscle tests is warranted.

Objective: After traumatic brain injury (TBI), postural instability often results. This can effect ambulation and, subsequently, activities of daily living. Various forms of rehabilitation have been developed, but few offer engaging activities that provide informative dynamic balance training. The goal of this pilot study was to build a goal-based system that provided visual biofeedback to create an enriched environment for dynamic postural rehabilitation. The study aimed to determine if visual biofeedback had an effect on posture and balance during training for healthy participants; as well as determine the optimal man-machine visual-biofeedback interface. Method: A modified elliptical trainer was developed that incorporated visual-biofeedback from measured left and right lower extremity loads. Four visual displays were constructed and tested on a sample of 15 healthy participants. These displays provided targeted feedback to aid in symmetric performance. The displays differed in the amount of information provided and in the extent of algorithmic pre-processing. Data were evaluated by calculating the index of symmetry (IOS) and statistically comparing display types. Results: Participants performed significantly better with the introduction of visual biofeedback than baseline measurements with no display based on index of symmetry values. The data suggests that the feedback display that incorporated both temporal historical data and differential pre-processing performed the best. This display was called the differential-temporal display. Conclusion: Our results reflect that performance is enhanced with the introduction of visual biofeedback during dynamic postural training. We also established that the differential-temporal display was the optimal feedback system to reduce IOS values during elliptical trainer use. From our results, it became apparent that incorporating visual biofeedback during postural training is a sophisticated approach to improve baseline asymmetries inherent in healthy participants. It is anticipated that similar results are likely to occur in a cohort of TBI patients due to the reduction of cognitive demand.

PURPOSE The use of electromyogram-based fatigue measurements during high-intensity, dynamic activities is confounded by the accompanying increase in muscle temperature. The purpose of this communication was to demonstrate the use of a muscle temperature compensation technique for electromyogram (EMG) fatigue measurements. METHODS Subjects were six healthy men (mean age 30.8 +/- 5.6 yr) with no recent history of lower extremity injury. In part 1 of this study, the relationship between muscle temperature and EMG mean power frequency was determined for the vastus lateralis muscle (VL). The VL was heated with diathermy to a temperature of approximately 39 degrees C. Isometric EMG data were collected during the performance of a nonfatiguing protocol as the muscle cooled (39-34 degrees C). In part 2 of this study, the subjects rode a lower-extremity ergometer at workloads of 25%, 50%, and 75% of their VO2max. Isometric EMG and intramuscular temperature data were collected from the VL during intermittent interruptions of the activity. The relationship between muscle temperature and EMG mean power frequency established in part 1 was used with the measured change in muscle temperature to correct for the effect of temperature on the EMG mean power frequency. RESULTS The results from part 1 revealed a linear relationship between EMG mean power frequency and muscle temperature (N = 5, mean slope = 2.82 +/- 0.27 Hz. degrees C-1, R2 = 0.88 +/- 0.02). The mean slope was used as a muscle temperature compensation factor that quantified the influence of muscle temperature on EMG mean power frequency. For part 2, representative data from a single subject are presented to demonstrate the use of the muscle temperature compensation technique. CONCLUSION A muscle temperature compensation technique for EMG mean power frequency analysis has been demonstrated. This technique corrects for the detrimental influence of muscle temperature changes on EMG fatigue measurements, thereby improving the efficacy of EMG fatigue measurements during high-intensity, dynamic activities that result in muscle temperature increases.

A training system intended for myoelectric prosthetic hands for upper limb amputees was developed to assist in learning myoelectric control schemes and training muscle isolation. The trainer allowed a user to operate a remote controlled car by use of a control scheme commonly used in myoelectric prosthetic hands. The trainer was designed to be easy for therapists to use and more engaging for the user than current methods of signal training. Preliminary testing of the trainer was conducted with eight nonamputee adult volunteers. The results indicated that the trainer could be a useful tool for myoelectric training in upper limb amputees. All subjects' skill with the myoelectric control scheme improved over the course of testing, with the improvements being greater at the beginning of the training period than at the end. Whereas the individual subjects' performance varied greatly at the beginning of the training, the subjects had achieved a more uniform level of performance by the end of the training, approaching the minimum possible values for the assessments.

Introduction: Although there are a number of research studies investigating walking recovery after stroke, most focus on one intervention or piece of equipment in order to achieve a controlled experimental environment. Such studies have yet to produce a comprehensive clinical practice guideline (CPG) for gait training. To fill this void, we implemented a clinical program for walking recovery, iWalk™, using a variety of advanced technologies, and an evidence-based CPG to assist in making assessment and intervention decisions. This study compares outcomes of patients treated using a traditional therapy program to those treated with the iWalk program. Hypothesis: The systematic application of a novel, evidence-based CPG for walking recovery will result in superior motor performance when compared to traditional therapy in patients post stroke. Methods: This study included all stroke survivors admitted to a rehab facility during a 24 month period, with the cohort split into two groups. The control group received traditional rehabilitation (n=152) and the experimental group received the iWalk protocol (n=165). Since full implementation of the protocol could not be assigned a specific date, a buffer group (n=50) between the two groups was excluded from this analysis. Results: Functional Independence Measure: An interaction between age and treatment program was detected (p Length of Stay: When examining LOS as an outcome, an interaction between treatment group and total FIM score was detected (p=0.073). Patients who were lower functioning on admission were more likely to be discharged home if they were in the iWalk program. Examining LOS as a predictor, the difference in timed-up-and-go scores between the treatment groups reveals that iWalk seems to be better for a LOS around 3 weeks, but is not significant (p>0.05). Conclusions: This study demonstrates outcome differences that favor iWalk. Additionally, there may be a LOS range which optimizes motor recovery. It is unclear whether a patient’s LOS is a reflection of the improvement of clinical variables or practical reasons. Further work is necessary on this topic.

Setting: Outpatient rehabilitation clinic. Patient: A 37-year-old physically active male. Case Description: The patient presented with anterior left knee pain, exacerbated when climbing stairs, sitting, and running. Exam showed lateral tracking patellae and palpable crepitus. One hundred fifty units of botulinum toxin A was injected into his left vastus lateralis. He underwent a 12-week home exercise program targeting the vastus medialis (VM). Assessment/Results: Visual analog scale decreased from 70 to 0 on a 150-mm scale, from initial until 8 weeks postinjection. Functional Index Questionnaire increased from 5 to 16 over the same period. Knee torque and surface electromyography findings showed increased activity of the VM during knee extension. Conclusion: Botulinum injection into the vastus lateralis in conjunction with VM strengthening may provide more effective treatment of patellofemoral pain syndrome. Further study is needed to explore this novel treatment of patellofemoral pain syndrome.

Objective: To determine sacroiliac joint compliance characteristics and pelvic floor movements in older women relative to gynecological surgery history and back pain complaints. Design: Single-visit laboratory measurement. Setting: University clinical research center. Participants: Twenty-five women aged 65 years or older. Outcome Measures: Sacroiliac joint compliance measured by Doppler imaging of vibrations and ultrasound measures of pelvic floor motion during the active straight leg raise test. Results: Doppler imaging of vibrations demonstrated test reliability ranging from 0.701 to 0.898 for detecting vibration on the ilium and sacrum sides of the sacroiliac joint. The presence of low-back pain or prior gynecological surgery was not significantly associated with a difference in the compliance or laxity symmetry of the sacroiliac joints. No significant difference in pelvic floor movement was found during the active straight leg raise test between subject groups. All P values were ≥.4159. Conclusions: Prior gynecological surgery and low-back pain were not significantly associated with side-to-side differences in the compliance of the sacroiliac joints or in significant changes in pelvic floor movement during a loading maneuver in a group of older women.

The objective of this study was to investigate the relationship between isometric GM torque and the degree of frontal plane pelvic drop during running. Twenty-one healthy, recreational runners (9 males, 12 females) who ran 8.05 km or more per week were obtained from a sample of convenience. GM maximal isometric torque was collected prior to the run. Subjects then ran on a treadmill for 30 minutes while bilateral three-dimensional pelvic kinematic data were collected for 10 seconds at each 2 minute increment. Left side pelvic drop showed a slight increase (effect size = 0.61); while, the right side pelvic drop remained stable (effect size = 0.18). Pearson's Correlations showed no relationship between GM isometric torque and frontal plane pelvic drop for any of the data collection periods during the 30-minute run. These results suggest that isometric GM torque was a poor predictor of frontal plane pelvic drop. One should question whether a dynamic rather than static measure of GM strength would be more appropriate. Future research is needed to identify dynamic strength measures that would better predict biomechanical components of running gait. Key pointsThere is a lack of research linking static, clinical measures to dynamic running gait observations.Isometric gluteus medius muscle torque is a poor predictor of frontal plane pelvic drop in running.Future studies should identify dynamic strength measures that correlate with elements of running biomechanics.

Background This report illustrates the use of pressure for scar management to aid in foot re-shaping following a surgical intervention to repair an arterio-venous (AV) malformation. Methods This report describes the rehabilitation of a 13-year-old girl after surgical reconstruction of a defect in her left foot following the removal of an AV malformation. Early surgical attempts to repair the problem resulted in complications that required the amputation of toes 2, 3, and 4, and the use of a split thickness skin graft to cover the plantar surface of the medial longitudinal arch on the left foot. Following surgery, the patient had an antalgic gait pattern with decreased weight bearing on the left. The graft obliterated the left medial longitudinal arch and the patient would only weight bear on the heel. The patient had decreased metatarsal joint mobility on the affected side and no movement in the remaining toes. Left talocrural joint active range-of-motion (AROM) was within normal limits and gross ankle muscle force production was assessed to have a grade of 3/5. Results Treatment included reshaping the left foot using a pressure garment and orthotic, followed by interventions to address range-of-motion and muscle force production deficiencies. All treatment objectives were achieved and all patient goals were achieved. Conclusions Pressure was effective in re-shaping the foot to promote normal gait mechanics.

Purpose To present the management of a patient with a cervical disc herniation and illustrate the efficacy of cervical traction as a main form of treatment for cervical disc herniation in conjunction with a home exercise program. Background A 71-year-old white female diagnosed with cervical disc herniation at the levels of C5-6 and C6-7 presented to physical therapy with neck pain radiating into the left upper extremity down to the 5th digit of the left hand. Treatment The patient reported to outpatient physical therapy for cervical disc herniation and radiculopathy. After initial evaluation she received intermittent cervical traction and was given a home exercise program consisting of cervical lateral flexion stretch, unilateral wall stretch for pectoralis muscles and to continue with her over the door cervical traction. Conclusion Cervical traction and a good home exercise program have been shown to reduce cervical disc herniation and its subsequent symptoms.

Background and Purpose This case report describes the rehabilitation of an elite, 15-year-old gymnast after a nonreduced type II manubriosternal dislocation. The rehabilitation took place in a gymnastics venue but was guided by a physician and a licensed physical therapist. Case Description The gymnast participated in a 13-week rehabilitation program for range of motion and strengthening that was based on a biomechanical hierarchy. Rehabilitation began at week 2 after injury for the lower extremities and at week 4 for the upper extremities. Outcomes By week 4, the patient began upper-extremity strengthening, and by week 6, the patient had no pain with palpation and tolerated light sternal loading. At week 9, a plain-film radiograph revealed a stable manubriosternal joint, and by week 13, the patient returned to gymnastics pain-free. Discussion This case report shows that, after a 13-week regimen of progressive and repetitive, cyclical tensile and compressive loading, the manubriosternal joint was stable, and the elite gymnast was able to return to the sport, successfully competing in a regional competition.

Scapular muscle performance evaluated with a handheld dynamometer (HHD) has been investigated only in people without shoulder dysfunction for test-retest reliability of data obtained with a single scapular muscle test. The purpose of this study was to assess the reliability, error, and validity of data obtained with an HHD for 4 scapular muscle tests in subjects with shoulder pain and functional loss.Subjects (N=40) with shoulder pain and functional loss were tested by measuring the kilograms applied with an HHD during 3 trials for muscle tests for the lower trapezius, upper trapezius, middle trapezius, and serratus anterior muscles. Concurrently, surface electromyography (sEMG) data were collected for the 4 muscles. The same procedures were performed 24 to 72 hours after the initial testing by the same tester. Muscle tests were performed 3 times, and the results were averaged for data analysis.Intraclass correlation coefficients for intratester reliability of measurements of isometric force obtained using an HHD ranged from .89 to .96. The standard error of the measure (90% confidence interval [CI]) ranged from 1.3 to 2.7 kg; the minimal detectable change (90% CI) ranged from 1.8 to 3.6 kg. Construct validity assessment, done by comparing the amounts of isometric muscle activity (sEMG) for each muscle across the 4 muscle tests, revealed that the muscle activity of the upper trapezius and lower trapezius muscles was highest during their respective tests. Conversely, the isometric muscle activity of the middle trapezius and serratus anterior muscles was not highest during their respective tests.In people with shoulder pain and functional loss, the intrarater reliability and error over 1 to 3 days were established using an HHD for measurement of isometric force for the assessment of scapular muscle performance. Error values can be used to make decisions regarding individual patients. Construct validity was established for the lower and upper trapezius muscle tests; therefore, these tests are advocated for use. However, construct validity was not demonstrated for the serratus anterior and middle trapezius muscle tests as performed in this study. Further investigation of these muscle tests is warranted.

Purpose Experiments were conducted on five subjects with no visual impairment to assess tracking strategy differences in subjects with and without a simulated central scotoma. Methods Subjects were asked to visually track horizontally moving periodic and nonperiodic sinusoidal stimuli through a +/-5 degrees range. Scotoma simulation was achieved electronically with a closed-loop feedback system using horizontal eye movement measurements from a monocular limbus eye tracker updated at a rate of 500 Hz. The scotoma was centrally located and had defined horizontal half widths of 1, 2, and 3 degrees . Vertical eye position measurements from a video-based dark-pupil tracker were used to identify and remove trials in which extreme vertical eye position deviations reduced the effectiveness of the simulation. Results All subjects developed a preferred retinal locus (PRL) in the left visual field and demonstrated a tendency for saccadic redirection to this area. Saccadic endpoints into the PRL outnumbered foveally directed saccades by a factor of 2:1. The PRL was located outside the compromised central vision region, typically near the edge of the scotoma boundary, for all subjects except one. This subject had a PRL within the simulated scotoma under two conditions, but the percentage of total time spent at the "compromised" PRL was less than for other subjects. Conclusions Subjects with no visual impairment confronted with a central scotoma develop a preferred retinal locus to replace the nonfunctional fovea and appear to suppress normal refoveating saccadic behavior in favor of this location.

The purpose of this study was to determine the effect of heel lifts on ground reaction force patterns in subjects with structural leg-length discrepancies (LLDs). Eighteen subjects with LLDs ranging from 4.8 to 22.2 mm participated in this study. Subject age range was from 20 to 63 years. A force platform was used to obtain ground reaction force data for four conditions. Data were collected prior to fitting of the heel lift and after a three-week break-in period. Data were analyzed by use of a two-factor within-subject analysis of variance for repeated measures. Before heel-lift fitting, maximum lateral force was greater in the short leg than in the long leg. After heel-lift fitting, maximum vertical force was greater within both legs, and maximum medical force was greater in the long leg than in the short leg. The results suggest that although heel lifts are used to achieve pelvic levelness, the use of heel lifts also resulted in increased ground reaction forces, which may cause increased joint stresses within the lower extremities.