Acute Effects Of Static Stretching On Handgrip Strength And Wrist Joint Flexibility In Older Women

Static stretching is often performed prior to physical activity or exercise to increase flexibility. A stretch-induced increase in flexibility may be accompanied by a reduction in muscle strength. Numerous studies have reported decreases in muscle strength after an acute bout of static stretching. Such decreases have been observed primarily in young, college-aged adults. Few studies have investigated the muscle strength and flexibility responses to stretching in older individuals. PURPOSE: To determine the acute effects of static stretching on handgrip strength and wrist joint flexibility in older women. METHODS: Twenty older women (68 ± 6 years) performed handgrip contractions and wrist joint flexibility assessments before (Pre) and after (Post) a control treatment and a stretching treatment. The stretching treatment consisted of one, 30-second passive static stretch of the wrist flexor muscles, and the control treatment consisted of quiet resting for 30 seconds. Handgrip contractions were performed using a novel strength testing device. For each contraction, participants were instructed to squeeze the handles of the device “as hard and fast as possible” for 3-4 seconds. Handgrip peak force was calculated and displayed by the device at the conclusion of each contraction. Wrist joint flexibility assessments were performed using a goniometer smartphone application. For the assessments, participants were instructed to actively extend their wrist joint to the maximum available range of motion (ROM). Each participant was given several seconds to reach the end of their available range, at which point, the maximum ROM was calculated and displayed by the smartphone application. RESULTS: No significant change in handgrip peak force was observed from pre- to posttest for the control (Pre = 2.42 ± 0.5 N·kg-1; Post = 2.39 ± 0.5 N·kg-1; P = 0.49) or stretching treatments (Pre = 2.36 ± 0.4 N·kg-1; Post = 2.39 ± 0.4 N·kg-1; P = 0.31). There was a significant increase in ROM from pre- to posttest for the stretching treatment (Pre = 80.1 ± 8.3°; Post = 87.9 ± 8.6°; P < 0.01) but not for the control (Pre = 82.2 ± 6.8°; Post = 83.3 ± 7.3°; P = 0.07). CONCLUSION: These findings suggest that static stretching for 30 seconds may be an effective intervention for increasing wrist joint flexibility without decreasing handgrip strength in older adults. Supported by: Funding for this study was provided by the Texas Society for Hand Therapy.