Neuromuscular and biomechanical characteristic changes in high school athletes: a plyometric versus basic resistance program.

BACKGROUND: In order to improve neuromuscular and biomechanical characteristic deficits in female athletes, numerous injury prevention programs have been developed and have successfully reduced the number of knee ligament injuries. However, few have investigated the neuromuscular and biomechanical changes following these training programs. It is also largely unknown what type of program is better for improving the landing mechanics of female athletes. OBJECTIVES: To investigate the effects of an 8 week plyometric and basic resistance training program on neuromuscular and biomechanical characteristics in female athletes. METHODS: Twenty seven high school female athletes participated either in a plyometric or a basic resistance training program. Knee and hip strength, landing mechanics, and muscle activity were recorded before and after the intervention programs. In the jump-landing task, subjects jumped as high as they could and landed on both feet. Electromyography (EMG) peak activation time and integrated EMG of thigh and hip muscles were recorded prior to (preactive) and subsequent to (reactive) foot contact. RESULTS: Both groups improved knee extensor isokinetic strength and increased initial and peak knee and hip flexion, and time to peak knee flexion during the task. The peak preactive EMG of the gluteus medius and integrated EMG for the gluteus medius during the preactive and reactive time periods were significantly greater for both groups. CONCLUSIONS: Basic training alone induced favourable neuromuscular and biomechanical changes in high school female athletes. The plyometric program may further be utilised to improve muscular activation patterns.

Proprioception of the ankle and knee.

Proprioception and accompanying neuromuscular feedback mechanisms provide an important component for the establishment and maintenance of functional joint stability. Neuromuscular control and joint stabilisation is mediated primarily by the central nervous system. Multisite sensory input, originating from the somatosensory, visual and vestibular systems, is received and processed by the brain and spinal cord. The culmination of gathered and processed information results in conscious awareness of joint position and motion, unconscious joint stabilisation through protective spinal-mediated reflexes and the maintenance of posture and balance. Clinical research aimed at determining the effects of articular musculoskeletal injury, surgery and rehabilitation, on joint proprioception, neuromuscular control and balance has focused on the knee and ankle joints. Such studies have demonstrated alterations in proprioception subsequent to capsulo-ligamentous injury, partial restoration of proprioceptive acuity following ligamentous reconstruction, and have suggested beneficial proprioceptive changes resulting from comprehensive rehabilitation programmes.

Quadriceps strength and functional capacity after anterior cruciate ligament reconstruction. Patellar tendon autograft versus allograft.

Harvesting the central third of the patellar tendon for autograft anterior cruciate ligament reconstruction is thought to compromise quadriceps strength and functional capacity. We compared objective measurements of quadriceps strength and functional capacity in athletes after patellar tendon autograft or allograft anterior cruciate ligament reconstruction. We looked at 33 active male patients (mean age, 24.3 years) who had anterior cruciate ligament reconstructions 12 to 24 months earlier using patellar tendon autograft (N = 15) or allograft (N = 18) techniques. All patients underwent an intensive rehabilitation program. Quadriceps strength and power were assessed by measuring peak torque at 60 and 240 deg/sec, torque acceleration energy at 240 deg/sec, and the quadriceps index using a Cybex II isokinetic testing device. Functional capacity was evaluated based on the results of 3 specially designed functional performance tests and the hop test. Results revealed no significant difference between autograft and allograft groups with respect to any of these parameters. These findings indicate that harvesting the central third of the patellar tendon for autograft anterior cruciate ligament reconstruction does not diminish quadriceps strength or functional capacity in highly active patients who have intensive rehabilitation. Thus, the recommendation to avoid patellar tendon autograft anterior cruciate ligament reconstruction to preserve quadriceps strength and functional capacity may be unnecessary.

The role of proprioception in the management and rehabilitation of athletic injuries.

Rehabilitation continues to evolve with the increased emphasis on patient management and proprioceptive training. Proprioception can be defined as a specialized variation of the sensory modality of touch that encompasses the sensation of joint movement (kinesthesia) and joint position (joint position sense). Numerous investigators have observed that afferent feedback to the brain and spinal pathways is mediated by skin, articular, and muscle mechanoreceptors. Examining the effects of ligamentous injury, surgical intervention, and proprioceptively mediated activities in the rehabilitation program provides an understanding of the complexity of this system responsible for motor control. It appears that this neuromuscular feedback mechanism becomes interrupted with injury and abnormalities, and approaches restoration after surgical intervention and rehabilitation. Rehabilitation programs should be designed to include a proprioceptive component that addresses the following three levels of motor control: spinal reflexes, cognitive programming, and brainstem activity. Such a program is highly recommended to promote dynamic joint and functional stability. Thus far, current knowledge regarding the basic science and clinical application of proprioception has led the profession of sports medicine one step closer to its ultimate goal of restoring function.

The effects of joint position and direction of joint motion on proprioceptive sensibility in anterior cruciate ligament-deficient athletes.

We studied a group of anterior cruciate ligament-deficient athletes to identify whether joint position and direction of joint motion have a significant effect on proprioception. Twenty-nine anterior cruciate ligament-deficient athletes were tested for their threshold to detect passive motion at both 15 degrees and 45 degrees moving into the directions of both flexion and extension. The single-legged hop test was used to identify function in the deficient limb. Results demonstrated statistically significant deficits in threshold to detect passive motion for the deficient limb at 15 degrees moving into extension. For the deficient limb, threshold to detect passive motion was significantly more sensitive moving into extension than flexion at a starting angle of 15 degrees; at a starting angle of 15 degrees moving into extension threshold was significantly more sensitive than at a starting angle of 45 degrees moving into extension. We conclude that in deficient limbs proprioception is significantly more sensitive in the end ranges of knee extension (15 degrees) and is significantly more sensitive moving into the direction of extension. To effectively restore reflex stabilization of the lower limb we recommend a rehabilitation program emphasizing performance-based, weightbearing, closed kinetic chain exercise for the muscle groups that act on the knee joint.

Knee joint laxity and neuromuscular characteristics of male and female soccer and basketball players.

Anterior cruciate ligament injuries are occurring at a higher rate in female athletes compared with their male counterparts. Research in the area of anterior cruciate ligament injury has increasingly focused on the role of joint proprioception and muscle activity in promoting knee joint stability. We measured knee joint laxity, joint kinesthesia, lower extremity balance, the amount of time required to generate peak torque of the knee flexor and extensor musculature, and electromyographically assessed muscle activity in 34 healthy, collegiate-level athletes (average age, 19.6 +/- 1.5 years) who played soccer or basketball or both. Independent t-tests were used to determine significant sex differences. Results revealed that women inherently possess significantly greater knee joint laxity values, demonstrate a significantly longer time to detect the knee joint motion moving into extension, possess significantly superior single-legged balance ability, and produce significantly greater electromyographic peak amplitude and area of the lateral hamstring muscle subsequent to landing a jump. The excessive joint laxity of women appears to contribute to diminished joint proprioception, rendering the knee less sensitive to potentially damaging forces and possibly at risk for injury. Unable to rely on ligamentous structures, healthy female athletes appear to have adopted compensatory mechanisms of increased hamstring activity to achieve functional joint stabilization.

Functional rehabilitation for the upper and lower extremity.

Functional rehabilitation is an extension of the traditional elements of physical therapy, the purpose of which is to return the athlete to highly complex movement patterns such as athletics. As well as the traditional elements of physical therapy such as strength and flexibility, the functional rehabilitation program incorporates agility and proprioceptive/kinesthetic training, which enables the athlete to participate at preinjury levels of activity while reducing the risk of recurrent injury. The functional rehabilitation program is designed to progress the athlete from simple activities, such as walking or jogging, to highly complex sport-specific activities that require refined levels of proprioceptive acuity. The final phase of the functional rehabilitation program is determining when the athlete is ready to resume participation in their respective sport. This is a very important and sometimes overlooked component of the functional rehabilitation program. The decision for returning an athlete to participation should be made using objective assessments of function that simulate sport activity whenever possible. Last, return to sport activity should be done gradually. Progression into the sport activity is essential to a full and healthy return to participation.

No acute changes in postural control after soccer heading.

BACKGROUND: Soccer heading has been proposed as a potential cause of cerebral dysfunction. OBJECTIVE: To examine the acute effects of two types of soccer heading on postural control. METHODS: Collegiate soccer players were randomly assigned to one of four groups: control, linear heading, simulated rotational heading, or rotational heading. Each subject completed a baseline postural stability assessment on day 1. On day 2 the same assessment was completed for the control subjects. The simulated rotational heading group completed a simulated heading drill before postural stability testing. The linear and rotational heading groups performed a heading drill with 20 balls at 88.71 km/h (55 mph), before postural stability testing. Separate one between (group), three within (surface, eyes, and day), mixed model, repeated measures analyses of variance were conducted on values for total sway and mean centre of pressure. RESULTS: The mixed model analysis of variance of results showed no significant differences (p>0.05) for the interactions of interest for either variable. Results suggest no acute changes in measures of postural control in soccer players completing either a linear or rotational soccer heading drill of 20 balls at a fixed speed. CONCLUSION: Non-significant interactions between surface, eyes, day, and group indicate that sensory interaction of the balance mechanism components are not be compromised by the heading drill. This research supports previous studies suggesting that there are no acute risks associated with routine soccer heading. A direct comparison between these findings and those suggesting long term chronic deficits, however, cannot be made. Other studies that report chronic cerebral deficits in soccer players may have resulted from factors other than soccer heading and warrant further examination.

Emergency treatment of athletic injuries.

Dental-related injuries continue to occur in high incidence in sporting events. Many of these injuries are preventable although the use of protective mouthguards remains sparce unless the rules of a particular sport explicitly dictate use during participation. Thus many athletes sustain dental-related injuries resulting in deformity and discomfort which may persist throughout their lives. Acute management of these injuries often determines the extent to which the dental disability is recoverable. It is essential that those health care professionals working directly with the athletes during competition reinforce the importance of protection and prevention as well as refine the skills necessary for immediate management of the injuries. Guidelines for management of dental injuries should be established by the team dental consultant and should be reviewed continually by team athletic trainers and team physicians. Often the primary care professional will determine the fate and ultimate recovery from the variety of dental injuries encountered regularly in sports.

Specificity of training on computer obtained isokinetic measures.

The purpose of this study was to examine the effects of 7 weeks of isokinetic training on knee extension and flexion peak torque, torque acceleration energy, average power, and total work, and to observe the relationship between the increases in each of the isokinetic measures. Seventeen intercollegiate lacrosse players served as subjects and were assigned to an exercise or control group. Isokinetic training consisted of 3 sets of 25 repetitions at 270 degrees /sec, 3 days per week for 7 weeks on an orthotron isokinetic dynamometer. All subjects were tested on a Cybex(R) isokinetic dynamometer at speeds of 60, 180, and 270 degrees /sec pre- and post-exercise or control condition. Results showed a significant training effect at 270 degrees /sec for knee extension peak torque, torque acceleration energy, and average power, and knee flexion torque acceleration energy. High correlations were observed between the increases in peak torque, average power, and torque acceleration energy. These findings suggest that increases in average power, peak torque and instantaneous power may be expected as a result of isokinetic exercise training in healthy athletes. J Orthop Sports Phys Ther 1989;10(12):495-498.

Changes in forearm blood flow during single and intermittent cold application.

STUDY DESIGN: Two-factor repeated measures design. OBJECTIVES: To compare the effects of a 20-minute cold application to the effects of a 20-minute cold application followed by 20 additional minutes of intermittent cold on forearm blood flow over a 60-minute period. BACKGROUND: The appropriate duration of cold application as a therapeutic modality following soft tissue trauma is an important clinical question because the goal of using this modality is to limit edema, decrease pain, and produce effective muscle relaxation without causing cold-induced reactive vasodilatation or nerve damage. METHODS AND MEASURES: Thirteen subjects (mean age, 21.46 +/- 4.01 years) volunteered to participate in this study. A bilateral tetrapolar impedance plethysmograph was used with venous occlusion to measure changes in local limb blood volume at the forearm for a period of 60 minutes under 2 conditions: Condition 1: Prolonged intermittent cold application (20 minutes ice application; 10 minutes off; 10 minutes ice on; 10 minutes off; 10 minutes ice on); Condition 2: Cold followed by application of a room-temperature pack of equal weight to the ice bag (20-minute ice application; 10 minutes off; 10 minute room-temperature pack on; 10 minutes off; 10-minute room-temperature pack on). RESULTS: A significantly lower blood flow was noted during the last 10 minutes of Condition 1 compared with Condition 2. CONCLUSIONS: The findings of this study indicate that blood flow is reduced when a prolonged intermittent cold application (Condition 1) is used compared to a single cold application (Condition 2).

Balance training for persons with functionally unstable ankles.

STUDY DESIGN: A nonrandomized 2-group pretest-posttest design. OBJECTIVES: To determine the effects of a 4-week balance training program during stance on a single leg. BACKGROUND: Individuals who have experienced multiple episodes of inversion ankle sprains often participate in balance training programs. Balance training is performed to treat existing proprioceptive deficits and to restore ankle joint stability, presumably by retraining altered afferent neuromuscular pathways. The effectiveness of such programs on individuals with functionally unstable ankles has yet to be established. METHODS AND MEASURES: Prior to and following training, subjects with self-reported functionally unstable ankles (5 women and 8 men, mean age = 21.9 +/- 3.1 years) and nonimpaired subjects (6 women and 7 men, mean age = 21.2 +/- 2.5 years) completed a static balance assessment for both limbs as well as the ankle joint functional assessment tool questionnaire (AJFAT). The subjects from both groups participated in a unilateral, multilevel, static and dynamic balance training program 3 times a week for 4 weeks. Subjects from the experimental group trained only the involved limb, and the nonimpaired group trained a randomly selected limb. A stability index (SI) was calculated during the balance assessment to indicate the amount of platform motion. Compared to low stability indices, high stability indices indicate greater platform motion during stance and therefore less stability. RESULTS: Following training, subjects from both groups demonstrated significant improvements in balance ability. When balance was assessed at a low resistance to platform tilt (stability level 2), the posttraining scores of both the subjects with unstable ankles (mean SI = 2.63 +/- 1.92) and the nonimpaired subjects (mean SI = 2.69 +/- 2.32) were significantly better than their pretraining scores (mean SIs = 5.93 +/- 3.65 and 4.67 +/- 3.43, respectively). Assessed at a high resistance to platform tilt (stability level 6), the posttraining scores of both subjects with unstable ankles (mean SI = 1.27 +/- 0.66) and the nonimpaired subjects (mean SI = 1.37 +/- 0.66) were significantly better than their pretraining scores (mean SIs = 2.30 +/- 1.88 and 2.04 +/- 1.43, respectively). Additionally, the posttraining AJFAT scores of subjects with unstable ankles (25.78 +/- 3.80) and the nonimpaired subjects (29.15 +/- 5.27) were significantly greater than their pretraining scores (17.11 +/- 3.44 and 22.92 +/- 5.22, respectively), indicating an overall improvement in perceived ankle joint functional stability. CONCLUSIONS: This study suggests that balance training is an effective means of improving joint proprioception and single-leg standing ability in subjects with unstable and nonimpaired ankles.

Comparison of performance-based and patient-reported measures of function in anterior-cruciate-ligament-deficient individuals.

There is a dearth of reliable and valid instrumentation that measures disability following injury and/or surgery of the knee joint that is responsive to clinically significant changes over time. The purpose of this investigation was to determine whether performance-based or patient-reported measures of function are more effective in estimating disability in individuals with an anterior-cruciate-ligament (ACL)-deficient knee. Subjective rating of knee function was used as the criterion measure for disability, and selected performance-based and patient-reported measures were used as estimation variables. Twenty-nine individuals with an ACL-deficient knee participated in this investigation. Step-wise regression analysis revealed that the Cincinnati Knee Scale, Lysholm Knee Scale, and hop index were the most effective estimates of disability. The results demonstrate that patient-reported measures are more related to the patient's level of disability in individuals with an ACL-deficient knee. More research is necessary to substantiate these findings.

The effect of sudden inversion stress on EMG activity of the peroneal and tibialis anterior muscles in the chronically unstable ankle.

Residual symptoms resulting from recurrent episodes of inversion-type ankle sprains may be attributed to a decreased neuromuscular response of the peroneal or tibialis anterior muscles, thereby increasing the probability for reinjury. The purpose of this study was to examine the electromyographic (EMG) response time of the peroneal and tibialis anterior muscles in response to sudden plantar flexion/inversion stress in the chronically functional unstable and normal ankle. Subjects for this study consisted of 13 athletically active individuals (five males and eight females, mean age = 19.2 +/- 1.51 years) with a previous history of a unilateral inversion-type ankle sprain. A specially designed platform that allows each foot to drop into plantar flexion/inversion from a standing neutral position was used. Reaction time in milliseconds for the peroneal and tibialis anterior muscles to sudden plantar flexion/inversion was measured via surface EMG. A paired t test was performed with the Bonferroni-Dunn correction factor to determine differences between the peroneal and tibialis anterior as well as between the chronically unstable and contralateral normal ankle. The results indicated no significant differences between the stable and unstable ankles for the peroneal or the tibialis anterior muscles. The results also indicated no significant differences existed between the tibialis anterior and peroneal muscles in either the stable or unstable ankles. The findings from the present study suggest that self-reported functional ankle instability may not result in a diminished reflex response time of the peroneal and tibialis anterior muscles to sudden plantar flexion/inversion stress.

Hop tests as predictors of dynamic knee stability.

Single leg hop tests are commonly used as physical performance measures of function and are also commonly used to evaluate progress in knee rehabilitation programs, particularly for individuals recovering from anterior cruciate ligament injury or reconstructive surgery. While there is some evidence that hop tests may show promise as a predictive measure for identifying individuals who are at risk for recurrent dynamic instability, further work is needed to clearly define the role of hop test measurements for this purpose. The purposes of this clinical commentary are to review the research that has been done to establish hop tests as a physical performance measure of function, to discuss neuromuscular and biomechanical considerations related to hop performance and dynamic knee stability, to discuss existing evidence that supports the potential for hop tests as a predictor of dynamic knee stability, and to discuss considerations for future studies that are designed to more clearly define the role of hop tests in predicting dynamic knee stability.

Shoulder kinesthesia in healthy unilateral athletes participating in upper extremity sports.

Shoulder kinesthesia has not been extensively studied in upper extremity athletes. The purpose of this study was to determine if there were differences in threshold to detection of passive motion between dominant and nondominant shoulders of healthy overhead athletes in two positions, 0 degrees and 75 degrees of external rotation. In addition, the study attempted to determine if there was a relationship between the range of external rotation (ER) and internal rotation (IR) and the threshold to detection of passive motion values. Shoulder kinesthesia was assessed in the dominant and nondominant shoulders of 20 collegiate athletes participating in unilateral upper extremity sports. A proprioceptive testing device passively moved the shoulder into internal and external rotation. The dominant shoulder had a significantly greater difficulty detecting motion compared with the nondominant arm at both 0 degrees and 75 degrees of external rotation. Both shoulders exhibited enhanced kinesthesia (lower threshold to detection of passive motion scores) at 75 degrees of external rotation compared with 0 degrees, where the glenohumeral joint capsule is relatively taut. The results of this study suggest that healthy upper extremity athletes may have kinesthetic deficits in their throwing shoulder compared with their nondominant shoulder.

Relationship between Selected Physical Characteristics and Functional Capacity in the Anterior Cruciate Ligament-Insufficient Athlete.

Traditionally, clinicians have utilized various physical characteristics as criteria to assess the functional status of anterior cruciate ligament (ACL)-insufficient athletes without validating the efficacy of such assessments. The primary purposes of this study were to determine the relationship between traditionally used physical characteristics and functional capacity of individuals with an ACL insufficiency and to compare functional results of two groups of ACL-insufficient athletes. Forty-one subjects were tested for strength and power on an isokinetic device, anthropometric characteristics, and function using three functional performance tests (FPT). Results revealed that conventional physical characteristics correlated poorly (r = .01 to r = .42) with the functional tests. Additionally, athletes who were able to return to preinjury levels of activity performed significantly (p < 0.05) better on the FPT than those who were unable to return to preinjury activities. Based on the results of this study, use of such traditional physical characteristics for predicting function in the ACL-insufficient athlete may be inappropriate, and the functional performance tests designed for this study appear to be the most valuable assessment of the athlete's functional capacity. J Orthop Sports Phys Ther 1992;16(4):174-181.

Comparison of two abdominal training devices with an abdominal crunch using strength and EMG measurements.

BACKGROUND: The purpose of this study was to compare the training effects of the Ab-Flex (F), Ab-Roller (R) and standard crunch (C) on EMG production, isometric maximum voluntary contraction (MVC), and isokinetic average peak torque at 30 degrees/sec (ISO) of the abdominal muscles. It was hypothesized that the training devices would have similar value in a strength training program. EXPERIMENTAL DESIGN: this was a prospective study involving 18 training sessions of progressively increasing repetitions. SETTING: Neuromuscular Research Laboratory, University of Pittsburgh. SUBJECTS: thirty-two subjects volunteered for this study, but only 26 completed the training. Each subject participated in recreational activity, but had not performed any abdominal training prior to starting this study. Each subject was randomly assigned to either the control group or one of the treatment groups. INTERVENTIONS: there were three interventions: two training devices (Ab-Flex and Ab-Roller) and the standard crunch, considered a control group. MEASURES: the pretest consisted of skin fold measurements (%), EMG activity (V) during the three interventions, and peak torque (Nm) plus EMG during the MVC and ISO tasks. The 18 training sessions over three weeks consisted of three sets of exercise with increasing repetitions from 10 to 20, by 2, every three sessions. The difference in pretest/posttest scores were compared using a One-way ANOVA on the mean differences (Mdiff) for each of: MVC, ISO (peak torque), and EMG for upper rectus (UR), lower rectus (LR), internal oblique (IO), and external oblique (EO). A T-Test was used to detect significance for the body fat measures. RESULTS: Mean differences (Mdiff) were normally distributed about zero for both MVC and ISO (MVC = -0.55, ISO = 4.57). The analysis by group showed no difference (p = 0.596) on the reported means (Nm) -3.16 (C), 5.84 (F) and -4.83 (R). The change associated to the treatment during MVC was only 4% (eta = 0.04). For the ISO the Mdiff (Nm) were 1.39 (C), 13.66 (F) and -2.06 (R) which were not significant (p = 0.127). The Ab-Flex was the only group to have a 95% confidence interval above zero, increasing by an average of 16.5%. There were no significant differences for the EMG activity for Mdiff or between group scores. CONCLUSIONS: No significant differences were found with this study. These results would suggest that using these devices does not add significantly to overall abdominal strength development, or reduction of body fat. A suggestion could be made that certain devices influence muscles differently.

Muscular and functional performance characteristics of individuals wearing prophylactic knee braces.

The efficacy of prophylactic knee bracing has been refuted with regard to reducing the incidence and/or severity of injuries to the knee joint. This is thought to be a result of the prophylactic knee brace's ineffectiveness in protecting the knee joint from valgus loads. Furthermore, discrepancies exist regarding the prophylactic knee brace's detrimental effect on functional performance. The purpose of this study was to measure the effect of the prophylactic knee brace on selected isokinetic muscular characteristics and forward sprint speed. Twenty physically active, healthy, male college students with no prior history of brace use participated in this study. The subjects were randomly tested both with and without the prophylactic knee brace worn on various performance parameters. The dependent measures assessed included peak torque (PT) and torque acceleration energy (TAE) at 60 and 240 degrees /s. A 40-yard forward sprint was selected to assess sprint speed. A paired t-test analysis revealed mean values which were significantly less for PT at 60 degrees /s (p < .05), 240 degrees /s (p < .01), and TAE at 240 degrees /s (p < .05) with the prophylactic knee brace applied during knee extension. Analysis also revealed slower times for sprint speed (p < .01), while the subjects were wearing the prophylactic knee brace. Muscular strength (PT) and power (TAE) scores were not correlated (p > .05) with sprint speed. This study suggests that wearing the prophylactic knee brace may consequently inhibit muscular and functional performance of the athlete, but that specific population has yet to be studied.

Chronic brachial plexopathies and upper extremity proprioception and strength.

Brachial plexopathies, where traction or compressive forces disrupt motor and sensory nerve conduction, are the most common nerve injuries in collision sports. Athletes frequently do not report these episodes, however, predisposing the brachial plexus to recurrent trauma. The purpose of this study was to identify how multiple injuries to the brachial plexus affects shoulder strength and proprioception. Ten male intercollegiate football players with at least three unilateral episodes of brachial plexopathies were tested an average of 10 weeks after the most recent episode. The uninvolved shoulder was used as the control. Isometric peak torque was assessed for shoulder abduction, external rotation, and elbow flexion. Proprioception was measured under two conditions: threshold to detection of passive motion and reproduction of passive positioning. Dependent t tests revealed significant mean differences (p < .05) between the involved and uninvolved extremity for abduction peak torque, overall mean peak torque, and one out of four conditions of threshold to detection of passive motion conditions. This was in the neutral position moving into external rotation. In addition, subjects with greater numbers of episodes exhibited larger strength deficits. The results of this study emphasize the need for timely re-evaluation of athletes with chronic brachial plexopathies.