Objectives: To determine the reliability of the one-arm hop test and the effects of upper-extremity dominance on test scores for 2 athletic groups.

Background: Limited information is available regarding functional performance tests of the upper extremity that involve axial loading. Methods and Measures: Thirteen male collegiate wrestlers (mean age, 20.3 ± 1.6 years) and 13 male collegiate football players (mean age, 20.0 ± 1.7 years) without upper-extremity pathology participated in the study. Subjects were trained to perform the one-arm hop test, starting from a one-arm push-up position and then hopping as quickly as possible onto and off of a 10.2-cm platform 5 times. Subjects returned to the test site 1 to 2 days later and were timed for 2 trials of the one-arm hop test for each upper extremity.

Results: Within-session ICC2,1 reliability values were 0.78 for the football players and 0.81 for the wrestlers. Mean absolute differences between trials were 0.64 seconds for the football players and 0.47 seconds for the wrestlers. Trial 2 performance times were significantly faster than trial 1 times for the wrestlers. Although performance time for the nondominant side was on average 4.4% slower than that of the dominant side, performance times for the dominant side were not significantly different from those of the nondominant upper extremities.

Conclusions: The results provide preliminary evidence that the one-arm hop test may be a reliable upper-extremity functional performance test with sufficient training of the subject. Uninjured upper-extremity performance for the one-arm hop test may be useful as a basis for comparing performance of an injured contralateral upper extremity.

J Orthop Sports Phys Ther. 2002; 32(3):98–103.

Key Words: functional performance test, upper extremity

Study Design: A counterbalanced repeated measures design. Objective: To determine the effect of a soft lumbar support on abdominal oblique muscle electromyography (EMG) during lifting. Background: Use of a soft lumbar back support is a common preventive measure to reduce the incidence of back injuries. Because the abdominal oblique muscles stabilize the spine during lifting, wearing this support may alter the activity level of these muscles. Methods and Measures: Twenty nonimpaired subjects (14 women and 6 men, mean age 28.9 ± 8.1 years) were tested using surface electrodes to record the EMG of the right abdominal oblique muscles during lifting with and without the support. Results: A paired t test revealed a significant decrease in activity of the abdominal oblique muscles during lifting with the support (29.7 ± 3.13 mV) compared to without it (33.3 ± 3.05 mV). Of the 20 subjects, the 14 women showed decreased EMG amplitude during the lift with the lumbar support compared to without the support, while 5 of the men showed increased EMG amplitude with the support and 1 man showed no change. Conclusion: This finding suggests that the soft lumbar support may play some role in the stabilization of the lumbar region during lifting.

J Orthop Sports Phys Ther. 2001;31(6):316-323.

Key Words: abdominal oblique muscles, lumbar support, surface electromyography