Reliability Of Handgrip Strength Measurements And Their Relationship With Physical Performance Outcomes In Older Women

Handgrip peak force and rate of force development (RFD) are effective measurements at characterizing the strength capacities of numerous muscle groups in the upper and lower extremities. Previous studies have determined the reliability of handgrip peak force and RFD in young, college-aged adults. However, the reliability of these measurements in older adults remains unclear. It is also unclear if these measurements are associated with performance during sit-to-stand and medicine ball throw tests. PURPOSE: The primary aim of this study was to examine the reliability of handgrip peak force and RFD measurements in older adults. A secondary aim was to determine if these measurements are related to sit-to-stand peak power and medicine ball throw distance. METHODS: Twenty older women (67.8 ± 5.8 years) reported for testing on two different occasions. For each testing session, participants completed five sit-to-stands, three seated medicine ball throws, and three handgrip maximal voluntary contractions (MVCs). Estimated peak power output was measured during the sit-to-stands using a linear velocity transducer. The distance of each medicine ball throw was recorded with a tape measure. Handgrip MVCs were performed using a novel strength testing device. For each MVC, participants squeezed the handles of the device “as hard and fast as possible” for 3-4 seconds. Handgrip peak force and RFD at 0-200 milliseconds were calculated and displayed by the device at the conclusion of each contraction. RESULTS: Reliability analysis revealed that peak force and RFD were highly consistent between sessions, with intraclass correlation coefficients of 0.950-0.978 and coefficients of variation of 2.7-4.3%. There were significant relationships between sit-to-stand peak power and handgrip peak force (r = 0.485, P = 0.030) and RFD (r = 0.533, P = 0.015). There were also significant relationships between medicine ball throw distance and handgrip peak force (r = 0.634, P = 0.003) and RFD (r = 0.605, P = 0.005). CONCLUSION: The results of this study showed that peak force and RFD were reliable measures for assessing handgrip strength in older women. These measurements were significantly associated with sit-to-stand peak power and medicine ball throw distance and thus, may be effective variables at predicting upper- and lower-body performance.