Ankle stiffness in postmenopausal women: Influence of hormone therapy and menopause nature

Background Literature suggests that muscle-tendon unit (MTU) stiffness is implicated in human motion performance and injuries. In addition, muscle and joint pains comprise a set of very common climacteric symptoms. Concomitant with such symptoms, physical fragility and mobility limitations are expected, which further affect the functional physical fitness of postmenopausal women. To the authors' knowledge, this is the first study relating MTU stiffness with hormone therapy (HT) and the nature of menopause. The purpose of this study was to investigate the influence of HT and the nature of menopause on triceps-surae MTU stiffness in postmenopausal women. Methods Ninety-three women participated in this study. The data concerning menopause were obtained through medical consultation. MTU stiffness was assessed invivo using a damped oscillation technique and a load equivalent to 30% of maximal voluntary isometric contraction. Results None of the following pair groups showed statistical differences for MTU stiffness: the HT group (19426 ± 4148 N/m) and the without-HT group (20056 ± 3579 N/m); the natural menopause group (19525 ± 3718 N/m) and the induced menopause group (20469 ± 4705 N/m). No significant differences were also found between the following pair groups: the natural menopause with-HT group (19078 ± 3910 N/m) and the without-HT group (20076 ± 3442 N/m); the induced menopause with-HTgroup (20756 ± 4932 N/m) and the without-HT group (19942 ± 4656 N/m). Conclusion The data suggest that MTU stiffness is not related to either the administration of HT in postmenopausal women or to the nature of menopause.