Tendon structural and mechanical properties do not differ between genders in a healthy community-dwelling elderly population.

Elderly women are reportedly at higher risk of falling than their male counterparts. Postural balance is highly associated with fall risk and is also correlated with tendon structural and mechanical properties. Gender differences in tendon properties could partly explain the discrepancy in fall risk. Thus the purpose of this study was to investigate the possible gender difference in tendon properties in the elderly. The properties of the patellar tendon of 55 elderly (men n = 27, aged 72 +/- 1 years, women n = 28, aged 70 +/- 1 years) participants were tested. Tendon stiffness (K), length (L), and cross-sectional area (CSA) were measured using B-mode ultrasonography, dynamometry, and electromyography during ramped isometric knee extensions. There were no significant differences (p > 0.05) between men and women in tendon stiffness (elderly men 550.9 +/- 29.2 vs. women 502.9 +/- 44.9 Nmm(-1)) or in Young's modulus (elderly men 0.32 +/- 0.02 vs. women 0.36 +/- 0.04 GPa). This elderly group had similar tendon structural and mechanical properties. The comparable characteristics in gender-specific tendon properties in an elderly population exhibiting similar lifestyle characteristics to the current sample may not explain the reports in the literature regarding increased fall risk in elderly women relative to that seen in men of a similar age.

Oestrogen status in relation to the early training responses in human thumb adductor muscles.

AIMS: The aims of this study were to identify the mechanisms for the early response to training in women of different oestrogen status and to determine whether any oestrogen and exercise effects on these would be additive. METHODS: We monitored training (ten 5-s contractions per day for 12 weeks)-induced changes in the size, strength, voluntary activation capacity and index of crossbridge force state (i.e. rapid stretch to isometric torque ratio), in the thumb adductor muscles of postmenopausal [eight who had never used, and 14 who were using, hormone replacement therapy (HRT)] and seven premenopausal eumenorrhoeic women. The contralateral untrained muscle was used as a control. RESULTS: There was a significant effect of oestrogen status on the magnitude of training-induced strength increment, with the non-HRT postmenopausal group exhibiting the greatest benefits (28 +/- 6%, P = 0.024) from training. There were no significant or commensurate changes in either cross-sectional area or voluntary activation capacity. The index of crossbridge force state improved most in the no-HRT group (19 +/- 7%, P < 0.05). CONCLUSIONS: Presence, rather than absence of oestrogen, is associated with relatively higher muscle function which limits the potential for any further training-induced increments in muscle performance, as would be expected if the muscle strengthening actions of training and oestrogen share a common, partially saturable physiological pathway. The mechanism that is involved in the early training-induced strength increment in the three differing oestrogen groups cannot be due to increased size or recruitment. It would appear instead that increased motor unit firing frequency is involved.