The detailed results from maximal isometric strength tests have been reported in an earlier publication (Samuel & Rowe, 2009). The mean peak knee muscle moments at 20°, 60° and 90° of knee flexion were 55.6 Nm, 53.1 Nm, IGF-1R inhibitor 46.3 Nm for flexors and −53.9 Nm, −97.8 Nm, −94.2 Nm for

extensors respectively. The mean peak hip muscle moments at 0°, 30° and 45° of hip flexion were 90.4 Nm, 84.6 Nm, 76.6 Nm for flexors and −47.3 Nm, −69 Nm, −71.4 Nm for extensors respectively (Samuel & Rowe, 2009). The FD data is presented for the cohort as a whole for each activity cycle for gait, CR and CSt incorporating both flexor (positive) and extensor (negative) demands in Fig. 1 Knee and Fig. 2 Hip. The FD profile during stair negotiation cycle has been presented elsewhere (Samuel et al., 2011). The maximal FDs for the three age groups during the five tasks are reported

in Table 1. The FD for older adults in the 80s age group was normally higher than those in the 60s and the difference in FD of 80-year-old participants ranged from 75 to 155 percent of that of the 60-year-olds. Age cohort-wise difference was not statistically significant however, an increasing trend was noticed in the overall FDs with increasing age particularly see more in the following measures, Gait – knee flexors, knee extensors, hip extensors; CR – knee extensors, hip extensors; CSt – knee extensors, hip extensors; SA – knee extensors,

hip extensors; SD – knee flexors, knee extensors, hip flexors and hip extensors. The FD on the extensors of hip and knee joints was normally higher than those of flexors across all the activities. For knee extensors, the overall FD values ranged from 69% for CSt to 120% for SD. The overall FD of hip extensors ranged from 51% for SD to 127% during gait. The knee extensor demand during gait (101%), SA (103%) and SD (120%); and hip extensor demand during gait (127%) were in excess of the maximum isometric muscle strength available. This is possible in eccentric and concentric modalities where more than maximum voluntary isometric strength can be elicited. The demand on knee flexors was high for gait (75%) and SD (73%) Pyruvate dehydrogenase lipoamide kinase isozyme 1 while a slightly lower hip flexor demand was noticed during gait (68%). The present study has provided a comprehensive analysis of FD at the knee and hip joints during everyday functional tasks measured on a large sample of older adults in three age groups. The findings of this study are unique as no previous study has investigated FDs on the knee and hip joints during a number of mobility-based activities. In addition, our data enhances our understanding of physical performance of older adults in terms of the FDs encountered at the knee and hip joints during everyday activities. The functional tasks that were found to be most demanding were gait, SA and SD.