Asynchronous Alterations of Muscle Force and Tendon Stiffness Following 8 Weeks of Resistance Exercise with Whole-Body Vibration in Older Women

• Published in: Journal of aging and physical activity Vol. 25; no. 2; p. 287
• Main Authors: Han, Seong-Won, Lee, Dae-Yeon, Choi, Dong-Sung, Han, Boram, Kim, Jin-Sun, Lee, Hae-Dong
• Format: Journal Article
• Language: English
• Published: United States 01.04.2017
• Subjects: Achilles Tendon - diagnostic imaging; Achilles Tendon - physiology; Aged; Electromyography; Female; Humans; Muscle Strength - physiology; Resistance Training - methods; Surveys and Questionnaires; Treatment Outcome; Vibration - therapeutic use; muscle force; whole-body vibration exercise; aging; tendon stiffness
• ISSN: 1543-267X
• DOI: 10.1123/japa.2016-0149

This study aimed to examine whether muscle force and tendon stiffness in a muscle-tendon complex alter synchronously following 8-week whole-body vibration (WBV) training in older people. Forty older women aged 65 years and older were randomly assigned into control (CON, n = 15) and whole-body vibration (WBV) training groups (exposure time, n = 13; vibration intensity, n = 12). For the training groups, a 4-week detraining period was completed following the training period. Throughout the training/detraining period, force of the medial gastrocnemius (MG) muscle and stiffness of the Achilles tendon were assessed four times (0, 4, 8, and 12 weeks) using a combined system of dynamometer and ultrasonography. While muscle force gradually increased throughout the training period (p < .05), a significant increase in tendon stiffness was observed after 8 weeks (p < .05). These findings indicated that, during the early phase of WBV training, muscle force and tendon stiffness changed asynchronously, which might be a factor in possible musculotendinous injuries.