Acute muscle stretching and shoulder position sense.

ABSTRACT

CONTEXT Stretching is common among athletes as a potential method for injury prevention. Stretching-induced changes in the muscle spindle properties are a suggested mechanism, which may imply reduced proprioception after stretching; however, little is known of this association. OBJECTIVE: To evaluate whether acute stretching of the shoulder muscles affects position sense. DESIGN: A crossover design with subjects randomized to 3 groups. SETTING: A university human research laboratory. PATIENTS OR OTHER PARTICIPANTS: Nine male (age = 24 +/- 3 years) and 9 female (age = 21 +/- 2 years) healthy volunteers. INTERVENTION(S) Stretching of shoulder (1) agonists or (2) antagonists or (3) nonstretching control. MAIN OUTCOME MEASURE(S) We determined position sense acuity of the right shoulder before and after the interventions by having subjects attempt to reproduce arm positions of 15 degrees and 30 degrees (shoulder adduction) while starting at 45 degrees to the sagittal plane. The outcome variables were response variability (variable error) and overall accuracy (absolute error). RESULTS: The relative change in variable error (ie, variable error after/variable error before) was not significantly different between the interventions ( P = .38). Similarly, no change in absolute error was found ( P = .76). Furthermore, no differences were noted regarding test sequence or the interaction of intervention x sequence for either variable error ( P = .73 and .53, respectively) or absolute error ( P = .71 and .67, respectively). CONCLUSIONS: We found no effect on shoulder position sense after an acute bout of stretching of either agonist or antagonist shoulder muscles.