Lower leg muscle activation during the ebbets foot drills.

Lateral ankle sprains (LAS) often lead to chronic ankle instability (CAI). The Ebbets foot drills were created to strengthen the lower leg muscles and reduce the risk of LAS. The current study aimed to explore the activation of the lower leg muscles during the Ebbets foot drills. Twenty-two (22) college students without LAS participated in the study. Surface electromyography (sEMG) of the tibialis anterior (TA), tibialis posterior (TP), and peroneus longus (PL) was collected during each of the Ebbets foot drills and a normal walking trial. The sEMG mean root mean square (RMS) was calculated for each walking and Ebbets foot drill trial duration. The mean RMS was higher during the Ebbets foot drills compared to normal walking for all muscles. The TA sEMG mean RMS was greater (4.0-68.3%, P = 0.001-0.023) during all the Ebbets foot drills than during the walking trial. The TP had greater mean RMS during the toe-in (50.4%, P < 0.001), toe-out (55.0%, P < 0.001), and backward walking (47.3%, P < 0.001) drills, than during the walking trial. The PL had greater mean RMS during all Ebbets foot drills (19.4-53.7%, P < 0.001) except for the heel walking and inversion drills. Ebbets foot drills higher muscle activity than regular walking, suggesting that the Ebbets foot drills could aid in the strengthening of the TA, TP, and PL muscles. These results build evidence on Ebbets' theory and indicate that these drills may be used to rehabilitate LAS and CAI.

Musicians Have Thicker Median Nerve Cross Sectional Area and More Symptoms of Carpal Tunnel Than Non-Musicians.

AIMS: Musicians spend numerous hours perfecting their skills and art, often leading to overuse injuries of the hand; of specific concern to musicians is carpal tunnel syndrome (CTS). This study evaluated the median nerve cross-sectional area and hand function of musicians and made comparisons to non-musicians. METHODS: Seventy-six participants took part in the study, 38 music students and professors in the musician group and 38 participants in the control group. Participants completed patient-reported questionnaires to assess the level of pain and hand function. Ultrasound images were collected at the carpal tunnel inlet and outlet. The median nerve cross-sectional area and the depth of the carpal tunnel were measured on ultrasound images using software imbedded in the ultrasound unit. RESULTS: Musicians showed higher levels of hand dysfunction and CTS symptoms than the non-musicians. The median nerve cross-sectional area was greater in musicians than in the non-musician group on both the right (mean difference 1.5 mm2, p=0.002) and left sides (mean difference 0.9 mm2, p=0.036). The depth of the carpal tunnel at the carpal tunnel inlet and outlet did not differ between the groups (p>0.05). CONCLUSION: The current research identified between-group differences in median nerve cross-sectional area and the level of hand dysfunction. Understanding the interaction between the anatomy of the wrist and wrist and hand dysfunction will benefit clinicians when evaluating and treating musicians.

The Effect of Repeated Shoulder Motion on Scapular Dyskinesis in Army ROTC Cadets.

INTRODUCTION: Altered or abnormal scapular motion has been associated with increased shoulder pain and dysfunction. Fatigue of the scapular stabilizing muscles resulting from repeated arm motion has been reported to alter scapular kinematics, which could result in the clinical assessment of scapular dyskinesis. The purpose of this study was to characterize the effect of repeated arm motion on the development of scapular dyskinesis. The hypothesis was that repeated arm motion will induce a subtle or obvious scapular dyskinesis. MATERIALS AND METHODS: About 30 army Reserve Officer Training Corps (ROTC) cadets participated in the research study. The cadets level of shoulder function was determined using the Quick Disabilities of the Arm Shoulder and Hand and Pennsylvania Shoulder Score shoulder scores. Cadets performed an exercise protocol of 30 repetitions of weighted shoulder motion in the frontal plane. Shoulder and scapular musculature strength measurements were recorded prior to and immediately following the exercise protocol using hand-held dynamometry. The scapular dyskinesis test was performed prior to the exercise protocol and during the last five repetitions of the exercise protocol. RESULTS: Prior to the exercise, protocol 3/30 were categorized with scapular dyskinesis on the left side and 3/30 were categorized with scapular dyskinesis on their right side. Following the exercise, protocol 8/30 were categorized with left-side scapular dyskinesis (χ2 = 9.167, P = 0.002) and 6/30 with right-side dyskinesis (χ2 = 4.537, P = 0.033). Shoulder strength decreased following the exercise protocol for all participants. The participants that developed scapular dyskinesis were weaker than those with normal scapular motion. However, the difference did not reach statistical significance. Participants graded with obvious scapular dyskinesis following the exercise protocol reported higher Quick Disabilities of the Arm Shoulder and Hand scores (P = 0.04) and lower scores on the Pennsylvania Shoulder Score (P = 0.005). CONCLUSIONS: Repeated shoulder motion increased the frequency of scapular dyskinesis in army ROTC cadets. The cadets that developed scapular dyskinesis also reported greater disability and lower function of the upper extremity. The results provide a link between scapular dyskinesis, upper extremity function, and the strength of the scapular stabilizing muscles. Improving the strength of the scapular stabilizing musculature might reduce the effects of repeated arm motions.

Wrist Flexion Exercise Increases the Width of the Medial Elbow Joint Space During a Valgus Stress Test.

OBJECTIVES: The medial elbow is stabilized during valgus loading by the ulnar collateral ligament, the flexor pronator mass (FPM), and the radial head. Impairment of the FPM can occur as a result of repeated wrist flexion activity. The purpose of this study was to determine the effect of repeated elbow flexion exercise on medial elbow stability. METHODS: Thirty volunteers were included in this study. Ultrasound images of the medial joint space of the nondominant elbow of the participants were collected during a valgus stress test. The images were collected before and immediately after a wrist flexion exercise protocol. RESULTS: The wrist flexion strength measure decreased (7.5%) after the exercise protocol (t = 3.840; P = .001). The medial elbow width increased between unstressed (mean ± SD, 2.8 ± 0.1 mm) and stressed (3.6 ± 0.1 mm) conditions (P < .001). The stress-by-fatigue interaction was significant (P = .048). The medial elbow width increased after fatigue (0.9 ± 0.09 mm) while remaining unchanged in the unstressed condition. CONCLUSIONS: This study found an effect of repeated wrist flexion exercise on decreasing the stability of the medial elbow. Future research needs to explore the mechanisms leading to the decrease in medial elbow stability and to identify the effect of FPM fatigue on the development of medial elbow pain associated with activities.

Ultrasound-Assisted Assessment of Medial Elbow Stability.

OBJECTIVES: An assessment of medial elbow stability is essential to the patient with an ulnar collateral ligament injury. Ultrasound imaging can be used to assess medial elbow stability. This study determined the effect of the elbow flexion angle on the medial elbow joint space during clinical tests of medial elbow stability. METHODS: Ultrasound images of the nondominant elbow were collected during 3 tests of medial elbow stability: valgus stress test, weighted valgus test, and milking maneuver. The elbow flexion angle increased between the valgus stress test and milking maneuver. The width of the medial joint space was measured on ultrasound images collected in unstressed and stressed conditions. RESULTS: Across test conditions, the medial joint width was greater in the stressed condition (mean ± SD, 3.7 ± 0.1 mm) than in the unstressed condition (2.9 ± 0.09 mm). The medial elbow joint space width was less (mean difference, 0.16 ± 0.01 mm; P = .01) in the milking maneuver position compared to the valgus stress test positions. CONCLUSIONS: This study provides evidence that changes in the width of the medial elbow during clinical evaluation of the unimpaired elbow can be detected by ultrasound. Changing the elbow flexion angle did not affect the change in width of the medial elbow during valgus loading.

Effect of Arm Position on Width of the Subacromial Space of Upper String Musicians.

OBJECTIVE: Musicians often end their musical career due to musculoskeletal injury. A leading source of shoulder pain in upper string musicians is rotator cuff disease (RCD). Multiple factors contribute to its development. Compressive overload of the soft tissues of the subacromial space resulting from a decrease in the width of the subacromial space has been identified as an extrinsic factor contributing to RCD development. The purpose of this study was to characterize the width of the subacromial space by measuring acromial-humeral distance (AHD) of upper string musicians, while their arms are in standard playing positions. METHODS: Experienced musicians (n=23) were recruited from local communities. Shoulder ultrasound images were collected using standard imaging techniques. Images were collected and the AHD measured while the musician's arm was in positions associated with playing the violin. RESULTS: On the right side, the arm position main effect was significant (p<0.001): the AHD in the 4th string position (8.8±1.9 mm) was less than the 1st string (11.3±1.4 mm) and resting (11.7±1.3 mm) positions. There was no difference in AHD between resting (10.0±5.8 mm) and instrument-support positions (10.6±1.5 mm). The resting AHD was smaller (p=0.04) on the right side compared to the left (12.2±1.4 mm). There was not statistically significant difference (p=0.138) in the occupation ratio (supraspinatus tendon thickness/AHD) between the right (mean 0.543±0.80 mm) and left sides (mean 0.510±0.087 mm). CONCLUSIONS: The AHD measurement decreased in the playing positions compared to resting positions. Treatment interventions that help musicians maximize the width of their subacromial space might help reduce the prevalence of shoulder pain in this population.