The peak moment developed across the range will over estimate the strength available at all points in the range other than the angle at which the peak moment is generated. We consider our approach which takes into account the length-tension relationship of the muscle to be more representative and to have greater

content validity. It should be noted that the knee extensors will be contracting eccentrically during the lowering phase of CSt and SD to control the movement as opposed to a isometric contraction. Eccentric strength was not measured in the current study and hence FD was computed using isometric strength. As isometric strength is lower than eccentric strength it is possible for the FD as calculated to exceed 100% overestimated. In addition, eccentric muscle strength has been observed to be relatively preserved in old age and does not show the same degree of decline with advancing selleck inhibitor age as noted with isometric and concentric muscle strengths (Lindle et al., 1997 and Vandervoort et al., 1990). Hortobágyi et al. (2003) observed that an increased FD in older adults was associated with an increased neural drive to the

involved muscle and an increased coactivity of antagonist muscles. It is possible that the increased muscle coactivation is due to the demanding nature Pirfenidone molecular weight of the tasks and that antagonistic action may exacerbate the situation further. What is striking from the data is that these everyday tasks pushed our participants 3-mercaptopyruvate sulfurtransferase to their maximal limits and in some cases over their isometric limit. SD was particularly demanding giving an FD of 120% at the knee for extensor group. This is possible as eccentric muscle strength can be approximately 20% greater than that measured isometrically. However the participants were clearly at their functional capacity descending stairs. In conclusion, analysis of FD during everyday activities was carried out in detail taking into account age and gender-based differences on a large sample of older adults. The FD on the knee and hip muscles increased with advancing age and the oldest group had the highest knee extensor and hip extensor demand. The published

data on functional activities is lacking in information on older adults who are over 80 years in age and muscle strength is shown to decline as people age with those in their 80s having the lowest strengths. Therefore, the FD values obtained in this study were found to be higher than those that have reported relative effort on a younger sample of older adults. The loss of muscle strength with advancing age might lead to an increase in the FD of performing simple everyday activities. The high demands could result in the older adult loosing the ability to perform these every day tasks safely. Furthermore, the physical challenge on the declining musculoskeletal system of the older adult could increase the risk associated with the tasks resulting in falls and injury. None declared.