Noninvasive Assessment of Internal and External Player Load: Implications for Optimizing Athletic Performance.

Heishman, AD, Curtis, MA, Saliba, E, Hornett, RJ, Malin, SK, and Weltman, AL. Noninvasive assessment of internal and external player load: implications for optimizing athletic performance. J Strength Cond Res 32(5): 1280-1287, 2018-Few data exist that assess athlete tracking and monitoring for the development of strategies to optimize performance and reduce fatigue in elite athletes. The purpose of the present study was to assess the efficacy of external load and internal stress monitoring as assessment tools for examining a performance index of fatigue. A retrospective analysis was performed on data collected over the course of the preseason in 10 elite male NCAA Division 1 basketball players. Internal stress was assessed using Omegawave Technology readiness scores and compared with the performance index of countermovement jump (CMJ). The external load that accumulated during the previous practice, quantified by PlayerLoad (PL; Catapult), was compared with CMJ values and Omegawave scores. The results indicated that high, compared to low CNS Omegawave Readiness Scores (6.7 ± 05.1, 4.5 ± 1.2 AU; p < 0.001), were associated with increased CMJ (62.1 ± 6.5 vs. 59.4 ± 6.6 cm; p = 0.05), Power (6,590 ± 526.7 vs. 6,383.5 ± 606.8 W; p = 0.05), Omegawave Overall Readiness (5.8 ± 1.1 vs. 5.0 ± 0.7 AU; p = 0.05), and Omega Potential (Omega) (21.3 ± 6.3 vs. 9.9 ± 20.8 mV; p = 0.07). An increased PL during the previous exposure was associated with decreased CMJ (58.7 ± 4.7 cm vs. 60.4 ± 5.1 cm; p < 0.001) and increased TRIMP (135.1 ± 35.9 vs. 65.6 ± 20.0 AU; p < 0.001), and duration (115.4 ± 27.1 vs. 65.56 ± 20.0 minutes; p = < 0.001) despite no differences in Omegawave CNS Readiness scores. We conclude that Omegawave and Catapult technologies provide independent information related to performance and may be effective tools for monitoring athlete performance.

Comparing Performance During Morning vs. Afternoon Training Sessions in Intercollegiate Basketball Players.

Time of day is a key factor that influences the optimization of athletic performance. Intercollegiate coaches oftentimes hold early morning strength training sessions for a variety of factors including convenience. However, few studies have specifically investigated the effect of early morning vs. late afternoon strength training on performance indices of fatigue. This is athletically important because circadian and/or ultradian rhythms and alterations in sleep patterns can affect training ability. Therefore, the purpose of the present study was to examine the effects of morning vs. afternoon strength training on an acute performance index of fatigue (countermovement jump height, CMJ), player readiness (Omegawave), and self-reported sleep quantity. We hypothesized that afternoon training sessions would be associated with increased levels of performance, readiness, and self-reported sleep. A retrospective analysis was performed on data collected over the course of the preseason on 10 elite National Collegiate Athletic Association Division 1 male basketball players. All basketball-related activities were performed in the afternoon with strength and conditioning activities performed either in the morning or in the afternoon. The average values for CMJ, power output (Power), self-reported sleep quantity (sleep), and player readiness were examined. When player load and duration were matched, CMJ (58.8 ± 1.3 vs. 61.9 ± 1.6 cm, p = 0.009), Power (6,378.0 ± 131.2 vs. 6,622.1 ± 172.0 W, p = 0.009), and self-reported sleep duration (6.6 ± 0.4 vs. 7.4 ± 0.25 p = 0.016) were significantly higher with afternoon strength and conditioning training, with no differences observed in player readiness values. We conclude that performance is suppressed with morning training and is associated with a decrease in self-reported quantity of sleep.

Exergaming and static postural control in individuals with a history of lower limb injury.

CONTEXT: Therapeutic exercise programs that incorporate real-time feedback have been reported to enhance outcomes in patients with lower extremity joint injuries. The Wii Fit has been purported to improve balance, strength, flexibility, and fitness. OBJECTIVE: To determine the effects of Wii Fit rehabilitation on postural control and self-reported function in patients with a history of lower limb injury. DESIGN: Single-blinded, randomized controlled trial. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Twenty-eight physically active participants with a history of lower limb injuries were randomly assigned to 1 of 3 groups (9 Wii Fit, 10 traditional, 9 control). INTERVENTION(S): Intervention groups performed supervised rehabilitation 3 d/wk for a total of 12 sessions. MAIN OUTCOME MEASURE(S): Time to boundary (TTB) and the Star Excursion Balance Test (SEBT) were conducted at baseline, 2 weeks, and 4 weeks. Self-reported function was measured at baseline and 4-week follow-up. Between-groups differences were compared using repeated-measures multivariate analysis of variance. RESULTS: With the eyes open, both intervention groups improved (P < .05) in the mean and the SD of the TTB anterior-posterior minima. In the eyes-closed condition, a time main effect (P < .05) for absolute TTB medial-lateral minima was observed. A time main effect was also noted in the posteromedial and posterolateral reach directions of the SEBT. When the scores for each group were pooled, improvement (P < .05) in self-reported function was demonstrated at 4-week follow-up. CONCLUSIONS: Rehabilitation using the Wii Fit and traditional exercises improved static postural control in patients with a history of lower extremity injury.

Talofibular interval changes after acute ankle sprain: a stress ultrasonography study of ankle laxity.

INTRODUCTION: Quantifying talocrural joint laxity after ankle sprain is problematic. Stress ultrasonography (US) can image the lateral talocrural joint and allow the measurement of the talofibular interval, which may suggest injury to the anterior talofibular ligament (ATFL). The acute talofibular interval changes after lateral ankle sprain are unknown. METHODS: Twenty-five participants (9 male, 16 female; age 21.8 ± 3.2 y, height 167.8 ± 34.1 cm, mass 72.7 ± 13.8 kg) with 27 acute, lateral ankle injuries underwent bilateral stress US imaging at baseline (<7 d) and on the affected ankle at 3 wk and 6 wk from injury in 3 ankle conditions: neutral, anterior drawer, and inversion. Talofibular interval (mm) was measured using imaging software and self-reported function (activities of daily living [ADL] and sports) by the Foot and Ankle Ability Measure (FAAM). RESULTS: The talofibular interval increased with anterior-drawer stress in the involved ankle (22.65 ± 3.75 mm; P = .017) over the uninvolved ankle (19.45 ± 2.35 mm; limb × position F1,26 = 4.9, P = .035) at baseline. Inversion stress also resulted in greater interval changes (23.41 ± 2.81 mm) than in the uninvolved ankles (21.13 ± 2.08 mm). A main effect for time was observed for inversion (F2,52 = 4.3, P = .019, 21.93 ± 2.24 mm) but not for anterior drawer (F2,52 = 3.1, P = .055, 21.18 ± 2.34 mm). A significant reduction in the talofibular interval took place between baseline and week 3 inversion measurements only (F1,26 = 5.6, P = .026). FAAM-ADL and sports results increased significantly from baseline to wk 3 (21.9 ± 16.2, P < .0001 and 23.8 ± 16.9, P < .0001) and from wk 3 to wk 6 (2.5 ± 4.4, P = .009 and 10.5 ± 13.2, P = .001). CONCLUSIONS: Stress US methods identified increased talofibular interval changes suggestive of talocrural laxity and ATFL injury using anterior drawer and inversion stress that, despite significant improvements in self-reported function, only marginally improved during the 6 wk after ankle sprain. Stress US provides a safe, repeatable, and quantifiable method of measuring the talofibular interval and may augment manual stress examinations in acute ankle injuries.

Relative acoustic transmission of topical preparations used with therapeutic ultrasound.

OBJECTIVE: To determine the relative acoustic transmission allowed by various preparations at 1MHz and 3MHz ultrasound (US) frequencies. DESIGN: Bench-top laboratory study. SETTING: Laboratory. PARTICIPANTS: No human or animal participants were used. INTERVENTIONS: We administered continuous US through various over-the-counter preparations at 1.2W/cm(2) at both 1MHz and 3MHz frequencies for 30 seconds and measured the acoustic output. MAIN OUTCOME MEASURES: Percentage of transmission of energy relative to commercial US gel. Planned observational comparisons were made at both 1MHz and 3MHz frequencies. Topical agents were categorized as either gel-based or cream-based preparations. RESULTS: Transmission of gel-based preparations (1MHz and 3MHz): Arnica gel (97% and 110%), Biofreeze (60% and 79%), Capzasin (70% and 93%), Cobroxin (76% and 91%), and Solarcaine (70% and 101%). Cream-based preparations (1MHz and 3MHz): Arnica cream (67% and 74%), Australian Dream (54% and 80%), Bengay (37% and 55%), MediPeds Footcare (126% and 101%), Neuragen PN (76% and 90%), Octogen (38% and 47%), and Thera-Gesic (52% and 73%). CONCLUSIONS: Topical agents suspended in aqueous gels are generally more effective in transmitting US energy, while many cream-based agents are less effective, particularly at 1MHz frequency. Many agents that are commonly used to provide a sensory effect, such as topical analgesic creams, may block US transmission. Agents that reduce US transmission may lead to poor phonophoresis results and are likely to minimize the therapeutic effects of US.

Differences in lateral ankle laxity measured via stress ultrasonography in individuals with chronic ankle instability, ankle sprain copers, and healthy individuals.

STUDY DESIGN: Cross-sectional. OBJECTIVE: To use stress ultrasonography to measure the change in anterior talofibular ligament length during the simulated anterior drawer and ankle inversion stress tests. BACKGROUND: In approximately 30% of individuals, ankle sprains may eventually develop into chronic ankle instability (CAI) with recurrent symptoms. Individuals with CAI and those who have a history of ankle sprain (greater than 1 year prior) without chronic instability (copers) may or may not have mechanical laxity. METHODS: Sixty subjects (n=60 ankles) were divided into 3 groups: 1) Control subjects without ankle injury history (n=20; mean ± SD age; 24.8 ± 4.8 years; height, 173.7 ± 9.4 cm; weight, 77.2 ± 19.5 kg), ankle sprain copers (n=20; 22.3 ± 2.9 years; 172.8 ± 11.3 cm; 72.4 ± 14.3 kg), and subjects with CAI (n=20; 23.5 ± 4.2 years; 174.6 ± 9.6 cm; 74.8 ± 17.3 kg). Ligament length change with the anterior drawer and end range ankle inversion was calculated from ultrasound images. The Foot and Ankle Ability Measure (FAAM) was used to quantify self-reported function on activities-of-daily living (ADL) and sports. RESULTS: The anterior drawer test resulted in length changes that were greater (F2,57=6.2, P=.004) in the CAI (mean ± SD length change, 15.6 ± 15.1%, P=.006) and the coper groups (14.0 ± 15.9%, P=.016) compared to the control group (1.3 ± 10.7%); however the length change for the CAI and coper groups were not different (P=.93). Ankle inversion similarly resulted in greater ligament length change (F2,57=6.5, P=.003) in the CAI (25.3 ± 15.5%, P=.003) and coper groups (20.2 ± 19.6%, P=.039) compared to the control group (7.4 ± 12.9%); with no difference in length change between the copers and CAI groups (P=.59). The CAI group had a lower score on the FAAM-ADL (87.4 ± 13.4%) and FAAM-Sports (74.2 ± 17.8%) when compared to the control (98.8 ± 2.9% and 98.9 ± 3.1%, P<.0001) and coper groups (99.4 ± 1.8% and 94.6 ± 8.8%, P<.0001). CONCLUSION: Stress ultrasonography identified greater length changes of the anterior talofibular ligament in both the coper and CAI groups compared to the control group. Only subjects with CAI had reductions in self-reported function.

Differential rates of recovery after acute sport-related concussion: electrophysiologic, symptomatic, and neurocognitive indices.

PURPOSE: To determine if motor evoked potentials (MEPs), postconcussion signs and symptoms, and neurocognitive functions follow a similar recovery pattern after concussion. METHODS: Nine collegiate athletes with acute concussion (>24 hours after injury) participated in this retrospective time series design. Transcranial magnetic stimulation was applied over the motor cortex, and MEPs were recorded from the contralateral upper extremity. Self-reported symptoms were evaluated using the Head Injury Scale, and the Concussion Resolution Index was used to assess neurocognitive function. All measures were repeated on days 3, 5, and 10 after injury. RESULTS: Composite scores on the Head Injury Scale were significantly higher on day 1 after injury (F3,51 = 15.3; P = 0.0001). Processing speed on the Concussion Resolution Index was slower on days 1, 3, and 5 compared with that on day 10 (F3,24 = 6.75; P = 0.0002). Median MEP latencies were significantly longer on day 10 compared with day 1 after concussion (t8 = -2.69; P = 0.03). Ulnar MEP amplitudes were significantly smaller on day 3 after concussion compared with day 5 (t8 = -3.48; P = 0.008). CONCLUSIONS: Acutely concussed collegiate athletes demonstrate changes in MEPs, which persist for up to 10 days after injury and do not follow the same recovery pattern as symptoms and neuropsychological test performance. The apparent differential rates of recovery most likely indicate different pathophysiological processes occurring in the immediate postconcussion period.

The anesthetic effect of lidocaine after varying times of phonophoresis.

OBJECTIVE: This study aimed to determine the anesthetic effect of 1-MHz phonophoresis using lidocaine on the anterior forearm following 5- and 10-min interventions. DESIGN: This was a crossover study in a laboratory involving 22 healthy participants (13 women, 9 men; age, 23.0 ± 3.2 yrs; height, 169.1 ± 7.2 cm; weight, 70.9 ± 13.9 kg). All subjects received four interventions on four different days: (1) 1.5 W/cm, 100% duty cycle with lidocaine for 5 mins (short); (2) 1.5 W/cm, 50% duty cycle with lidocaine for 10 mins (long); (3) no ultrasound for 10 mins with lidocaine gel (lidocaine sham); and (4) no ultrasound for 10 mins with ultrasound gel (true sham). Skin sensation was measured for analysis. The main outcome measures were Semmes-Weinstein Monofilament (SWM) scores, with higher scores indicating less sensitivity. RESULTS: There was a significant time main effect for SWM scores (P < 0.001). Baseline SWM scores were the lowest (3.00 ± .53; P ≤ 0.006) and post-SWM scores (0 mins) were the highest (3.63 ± .44; P < 0.001), indicating an anesthetic effect at this time. CONCLUSIONS: Neither the long nor the short treatment decreased skin sensation compared with sham conditions. All interventions resulted in decreased skin sensation when comparing baseline SWM scores to all posttreatment scores. Phonophoresis with lidocaine did not result in an enhanced anaesthetic effect on human subjects.

Cardiovascular screening and the elite athlete: advances, concepts, controversies, and a view of the future.

This article addresses programmatic cardiovascular screening and evaluation of the elite athlete at the intercollegiate, national team, professional, and Olympic levels. Although much of this content may apply to high-school and recreational sports at large, it is not specifically designed to address athletes participating in all sports activities.

No difference between doses in skin anesthesia after lidocaine delivered via iontophoresis.

CONTEXT: Iontophoresis is a method of administering medications transcutaneously using galvanic current. Dose is the product of current amplitude and treatment duration. It is assumed that higher doses of iontophoresis are more effective in delivering medication, yet research supporting this claim is insufficient. OBJECTIVE: To compare high-dose lidocaine iontophoresis (80 mA-min), standard-dose lidocaine iontophoresis (40 mA-min), and 2 sham treatments indirectly by measuring skin anesthesia. DESIGN: Double-blind crossover study. SETTING: Research laboratory. PARTICIPANTS: 15 healthy volunteers (10 women, 5 men: age 24.06 ± 2 y, height 169.7 ± 8.3 cm, weight 72.5 ± 14.2 kg). INTERVENTION: Four treatments were counterbalanced and applied on the anterior forearm: 2 true interventions (40 and 80 mA-min) and 2 sham interventions separated by at least 24 h. The true-intervention doses were applied at a current of 2 mA with 2.5 ml 2% lidocaine HCL for 20 and 40 min. The sham treatments were 2.5 ml of lidocaine without galvanic current (intensity = 0 mA, 40 min) and 2.5 ml of saline solution (galvanic current of 2 mA for 40 min). MAIN OUTCOME MEASURES: Semmes-Weinstein monofilament scores were taken preintervention and postintervention (at 0, 20, 40, and 60 min) to measure skin anesthesia. RESULTS: A significant interaction between treatment and time (F = 4.137, P < .01) was identified. The 40-mA-min dose produced greater anesthesia than the lidocaine and saline shams at all times. The 80-mA-min dose produced greater anesthesia than saline sham at all times. There was a significant difference noted, with 40 mA-min over 80 mA-min, at the 20-min posttest, but there were no other significant differences between the 40- and 80-mA-min doses at 0, 40, or 60 min posttreatment or between the 2 sham treatments at any time. CONCLUSIONS: The 40-mA-min treatment was just as effective as the 80-mA-min treatment, suggesting that shorter treatments may be more time efficient for clinicians and patients.

Cost and yield of adding electrocardiography to history and physical in screening Division I intercollegiate athletes: a 5-year experience.

BACKGROUND: Electrocardiographic screening of intercollegiate athletes is controversial because the costs and yield are not well defined. Both the American Heart Association (AHA) and the European Society of Cardiology (ESC) have different criteria for screening, partly because the populations being screened are different. OBJECTIVE: The purpose of this study was to determine the cost and yield of a 5-year ECG screening program at a United States Division I college. METHODS: At the University of Virginia, all 1,473 competitive athletes over the course of 5 years were screened with history and physical and with ECGs using ESC guidelines with follow-up testing as dictated by clinical symptoms and ECG findings. RESULTS: History and physical alone uncovered five significant cardiac abnormalities. ECGs were abnormal in 275 (19%), resulting in 359 additional tests. Additional testing confirmed eight significant cardiac abnormalities that were not found by history and physical: 1 bicuspid aortic valve, 4 rapidly conducting accessory pathways, 1 long QT patient, 1 with frequent premature ventricular contractions and low ejection fraction, and 1 with frequent premature ventricular contractions but normal ejection fraction. No cases of hypertrophic cardiomyopathy were found. Total cost of the program was US $894,870. Cost of history and physical screening alone was $343,725 or $68,745 per finding. The marginal cost of adding ECG screening, including resulting tests and procedures. was US$551,145 or US$68,893 per additional finding. CONCLUSION: ECG screening of U.S. college athletes can uncover significant cardiac pathology not discovered by history and physical alone. Although ECG screening also results in many false positives resulting in additional tests, the overall cost per diagnosis of adding ECG screening is similar to that of history and physical screening alone.

Effect of duration and amplitude of direct current when lidocaine is delivered by iontophoresis.

Dosage for the galvanic stimulation for iontophoresis varies. Clinicians manipulate the duration or the amplitude of the current, but it is not known which is more effective. We compared the anesthetic effect of lidocaine HCL (2%) by manipulating the current parameters on 21 healthy volunteers (age: 21.2 ± 4.2, height 170.7 ± 10.2 cm, mass 82.1 ± 19.2 kg). Three conditions were administered in a random order using a Phoresor II® with 2 mL, 2% lidocaine HCL in an iontophoresis electrode. (1) HASD (40 mA*min): High amplitude (4 mA), short duration (10 min); (2) LALD (40 mA.min): Low amplitude (2 mA), long duration (20 min); (3) Sham condition (0 mA, 20 min). Semmes-Weinstein monofilament (SWM) scores were taken pre and post intervention to measure sensation changes. Two-way ANOVA with repeated measures was used to compare sensation. Both iontophoresis treatments: LALD (4.2 ± 0.32 mm) and HASD (4.2 ± 0.52 mm) significantly increased SWM scores, indicating an increase in anesthesia, compared to the sham condition (3.6 ± 0.06 mm) p < 0.05. Neither LALD nor HASD was more effective and there was no difference in anesthesia with the sham. Lidocaine delivered via iontophoresis reduces cutaneous sensation. However, there was no benefit in either a HASD or LALD treatment.

A preliminary investigation of motor evoked potential abnormalities following sport-related concussion.

BACKGROUND: Assessment of concussion is primarily based on self-reported symptoms, neurological examination and neuropsychological testing. The neurophysiologic sequelae and the integrity of the corticomotor pathways could be obtained by evaluating motor evoked potentials (MEPs). OBJECTIVES: To compare MEPs obtained through transcranial magnetic stimulation (TMS) in acutely concussed and non-concussed collegiate athletes. METHODS: Eighteen collegiate athletes (12 males, six females, aged 20.4 +/- 1.3 years) including nine subjects with acute concussion ( 0.05). CONCLUSION: MEP abnormalities among acutely concussed collegiate athletes provide direct electrophysiologic evidence for the immediate effects of concussion.

Treatment of a female collegiate rower with costochondritis: a case report.

Rib injuries are common in collegiate rowing. The purpose of this case report is to provide insight into examination, evaluation, and treatment of persistent costochondritis in an elite athlete as well as propose an explanation for chronic dysfunction. The case involved a 21 year old female collegiate rower with multiple episodes of costochondritis over a 1-year period of time. Symptoms were localized to the left third costosternal junction and bilaterally at the fourth costosternal junction with moderate swelling. Initial interventions were directed at the costosternal joint, but only mild, temporary relief of symptoms was attained. Reexamination findings included hypomobility of the upper thoracic spine, costovertebral joints, and lateral ribs. Interventions included postural exercises and manual therapies directed at the lateral and posterior rib structures to improve rib and thoracic spine mobility. Over a 3-week time period pain experienced throughout the day had subsided (visual analog scale - VAS 0/10). She was able to resume running and elliptical aerobic training with minimal discomfort (VAS 2/10) and began to reintegrate into collegiate rowing. Examination of the lateral ribs, cervical and thoracic spine should be part of the comprehensive evaluation of costochondritis. Addressing posterior hypomobility may have allowed for a more thorough recovery in this case study.

Effects of balance training on gait parameters in patients with chronic ankle instability: a randomized controlled trial.

OBJECTIVE: To examine the effects of a four-week balance training programme on ankle kinematics during walking and jogging in those with chronic ankle instability. A secondary objective was to evaluate the effect of balance training on the mechanical properties of the lateral ligaments in those with chronic ankle instability. DESIGN: Randomized controlled trial. SETTING: Laboratory. SUBJECTS/PATIENTS: Twenty-nine participants (12 males, 17 females) with self-reported chronic ankle instability were randomly assigned to a balance training group or a control group. INTERVENTION: Four weeks of supervised rehabilitation that emphasized dynamic balance stabilization in single-limb stance. The control group received no intervention. MAIN OUTCOME MEASURES: Kinematic measures of rearfoot inversion/eversion, shank rotation, and the coupling relationship between these two segments throughout the gait cycle during walking and jogging on a treadmill. Instrumented ankle arthrometer measures were taken to assess anterior drawer and inversion talar tilt laxity and stiffness. RESULTS: No significant alterations in the inversion/eversion or shank rotation kinematics were found during walking and jogging after balance training. There was, however, a significant decrease in the shank/rearfoot coupling variability during walking as measured by deviation phase after balance training (balance training posttest: 13.1 degrees +/- 6.2 degrees , balance training pretest: 16.2 degrees +/- 3.3 degrees , P = 0.03), indicating improved shank/rearfoot coupling stability. The control group did not significantly change. (posttest: 16.30 degrees +/- 4.4 degrees , pretest: 18.6 degrees +/- 7.1 degrees , P40.05) There were no significant changes in laxity measures for either group. CONCLUSIONS: Balance training significantly altered the relationship between shank rotation and rearfoot inversion/eversion in those with chronic ankle instability.

Use of a combination of ankle pressure and SENSERite system to treat older adults with impaired ankle proprioception: a single-blind experimental study.

OBJECTIVE: To investigate the effects of a combination of visual biofeedback and ankle pressure on ankle position sense in elderly adults with and without impaired ankle joint position sense (JPS). DESIGN: Independent 2 x 3 factorial design with an experimenter-blind study. SETTING: University motion laboratory. PARTICIPANTS: Older adults (N=40) were recruited from local community centers. Among them, 21 elderly subjects had relatively normative score, whereas 19 subjects had impaired ankle position sense. INTERVENTION: Both the normative and impaired elderly subjects underwent either ankle JPS visual feedback training alone or a combination of ankle JPS visual feedback training and circumferential ankle pressure for one 30-minute training session. MAIN OUTCOME MEASURES: The outcome measures included ankle JPS errors measured in absolute constant error (ACE) and variable error (VE) during standing at pretest, posttest, and 1-week follow-up test. A separate repeated measures analyses of variance was performed to evaluate the differential training effects on ACE and VE, respectively. The Pearson chi-square test and Bonferroni test were performed. Significance was assigned at P less than .05 for all analyses. RESULTS: Regardless of intervention conditions, older adults with and without ankle position sense impairment showed immediate treatment benefits, which relatively remained stable even at the follow-up test. These effects were reflected in significant improvements of JPS accuracy and consistency (P<.05). CONCLUSIONS: Our findings may suggest that both interventions were equally effective in increasing ankle JPS accuracy and consistency in older adults with and without impairments, and therapeutic effects lasted for a week, reflecting long-term effect.

Jogging gait kinetics following fatiguing lumbar paraspinal exercise.

A relationship exists between lumbar paraspinal muscle fatigue and quadriceps muscle activation. The objective of this study was to determine whether hip and knee joint moments during jogging changed following paraspinal fatiguing exercise. Fifty total subjects (25 with self-reported history of low back pain) performed fatiguing, isometric lumbar extension exercise until a shift in EMG median frequency corresponding to a mild level of muscle fatigue was observed. We compared 3-dimensional external joint moments of the hip and knee during jogging before and after lumbar paraspinal fatigue using a 10-camera motion analysis system. Reduced external knee flexion, knee adduction, knee internal rotation and hip external rotation moments and increased external knee extension moments resulted from repetitive lumbar paraspinal fatiguing exercise. Persons with a self-reported history of LBP had larger knee flexion moments than controls during jogging. Neuromuscular changes in the lower extremity occur while resisting knee and hip joint moments following isolated lumbar paraspinal exercise. Persons with a history of LBP seem to rely more heavily on quadriceps activity while jogging.

Rehabilitation considerations of a brachial plexus injury with complete avulsion of c5 and c6 nerve roots in a college football player: a case study.

Severe brachial plexus injuries are rare in sports, but they have catastrophic results with a significant loss of function in the involved upper extremity. Nerve root avulsions must be timely managed with prompt evaluation, accurate diagnosis, and surgical treatment to optimize the potential for a functional outcome. This case report describes the mechanism of injury, diagnostic evolution, surgical management, and rehabilitation of a college football player who sustained a traumatic complete nerve root avulsion of C5 and C6 (upper trunk of the brachial plexus). Diagnostics included clinical evaluation, magnetic resonance imaging, computed tomography myelogram, and electromyogram. Surgical planning included nerve grafting and neurotization (nerve transfer). Rehabilitation goals were to bring the hand to the face (active biceps function), to stabilize the shoulder for abduction and flexion, and to reduce neuropathic pain. Direct current stimulation, bracing, therapeutic exercise, and biofeedback were used to maximize the use of the athlete's upper extremity. Although the athlete could not return to sport or normal function by most standards, his results were satisfactory in that he regained an ability to perform many activities of daily living.

Balance training improves function and postural control in those with chronic ankle instability.

PURPOSE: The purpose of this randomized controlled trial was to determine the effect of a 4-wk balance training program on static and dynamic postural control and self-reported functional outcomes in those with chronic ankle instability (CAI). METHODS: Thirty-one young adults with self-reported CAI were randomly assigned to an intervention group (six males and 10 females) or a control group (six males and nine females). The intervention consisted of a 4-wk supervised balance training program that emphasized dynamic stabilization in single-limb stance. Main outcome measures included the following: self-reported disability on the Foot and Ankle Disability Index (FADI) and the FADI Sport scales; summary center of pressure (COP) excursion measures including area of a 95% confidence ellipse, velocity, range, and SD; time-to-boundary (TTB) measures of postural control in single-limb stance including the absolute minimum TTB, mean of TTB minima, and SD of TTB minima in the anteroposterior and mediolateral directions with eyes open and closed; and reach distance in the anterior, posteromedial, and posterolateral directions of the Star Excursion Balance Test (SEBT). RESULTS: The balance training group had significant improvements in the FADI and the FADI Sport scores, in the magnitude and the variability of TTB measures with eyes closed, and in reach distances with the posteromedial and the posterolateral directions of the SEBT. Only one of the summary COP-based measures significantly changed after balance training. CONCLUSIONS: Four weeks of balance training significantly improved self-reported function, static postural control as detected by TTB measures, and dynamic postural control as assessed with the SEBT. TTB measures were more sensitive at detecting improvements in static postural control compared with summary COP-based measures.

Joint angle and contraction mode influence quadriceps motor neuron pool excitability.

OBJECTIVE: The purpose of the study was to compare the central activation ratio (CAR) of eccentric contractions to isometric contractions at 30 and 70 degrees of knee flexion. DESIGN: A repeated-measures design was used. CARs were measured at 30 and 70 degrees of knee flexion in 16 healthy subjects during both eccentric and isometric modes of contraction. CARs were measured using the superimposed burst technique. RESULTS: Isometric CARs at 30 degrees (0.88+/-0.069) of knee flexion were significantly higher (P<0.001) than at 70 degrees (0.77+/-0.116). Eccentric CARs were significantly higher (P=0.013) at 70 degrees (0.87+/-0.085) of knee flexion compared with 30 degrees (0.8+/-0.09). At 30 degrees of knee flexion, isometric CARs were significantly higher (P=0.003) than eccentric CARs. At 70 degrees, eccentric CARs were higher (P<0.001) when compared with isometric CARs. CONCLUSIONS: Our results provide evidence that isometric measures at a single joint angle are not sufficient in generalizing activation of an entire muscle group for dynamic movements. CARs are significantly affected by joint angle and mode of contraction.