Vertical Jump on a Force Plate for Assessing Muscle Strength and Power in Women With Severe Obesity: Reliability,...

Bellicha, A, Giroux, C, Ciangura, C, Menoux, D, Thoumie, P, Oppert, J-M, and Portero, P. Vertical jump on a force plate for assessing muscle strength and power in women with severe obesity: reliability, validity, and relations with body composition. J Strength Cond Res 36(1): 75-81, 2022-Muscle strength and power, particularly when assessed during multijoint movements such as vertical jump (VJ), are important predictors of health status and physical function. Vertical jump is mainly used in athletes, also in untrained or older adults, but has not yet been used in subjects with obesity. We aimed to assess the following in this population: (a) the reliability of VJ parameters, (b) their validity compared with isokinetic testing, and (c) their relations with body composition. In 20 women with severe obesity (mean [SD] age: 41.1 [11.6] years; body mass index: 43.9 [4.4] kg·m-2) without severe orthopedic disorders, VJ parameters, knee extension torque, and body composition were assessed using a force plate, an isokinetic dynamometer, and dual-energy x-ray absorptiometry, respectively. Excellent reliability was found for absolute peak power and peak force in VJ (intraclass correlation coefficient [95% confidence interval]: 0.95 [0.88-0.98] and 0.90 [0.77-0.96], respectively), and moderate to good validity of peak power and peak force compared with isokinetic torque (r = 0.79 and r = 0.67, respectively; all p < 0.01). Positive relations were found between peak force and peak power during VJ and lean body mass (r = 0.89 and r = 0.60, respectively; p < 0.01) and a negative relation was found between peak velocity or VJ height and fat mass (r = -0.65 and -0.64, respectively; p < 0.01). These results suggest that VJ on a force plate is a reliable and valid test for assessing muscle strength and power in severely obese subjects. Vertical jump testing is easy to implement, which can facilitate its use in both research and clinical testing in this setting (ClinicalTrials.govID: NCT03325764).