The left and right hip bones (innominate bones, pelvic bones) are two irregularly shaped bones that form part of the pelvic girdle - the bony structure that attaches the axial skeleton to the lower limbs.
Osteology Of Lower Limb Pdf Download
It has repeatedly been found that, percentage-wise, running speed declines more rapidly with age for endurance than for sprint running [7]. However, after biomechanical adjustment for kinetic energy, sprint and endurance running power decline with age in a remarkably similar fashion [17]. This is suggestive of a single mechanism for declining endurance and sprint capabilities. A recent cross-sectional study of bio-impedance based assessment of body composition in 256 masters athletes demonstrates that muscle wasting, which goes hand in hand with accumulated adipose tissue offers a viable explanation [18]. With regards to the present study, it is obviously important to consider that the vertical jump test is more related to sprinting capability than to endurance. In this respect, the present findings enhance the view of a general age-related impediment of muscle power across the board of sprint and endurance capabilities. Differences in findings between this study and a previous study in tennis players, where relative advantages in muscle function declined with age relative to the less active control arm [16], may be explained by lower habitual usage of the upper limbs, by occasional use of the non-playing arm in double-handed strokes or the greater power of a within rather than between-individual model. High intensity plyometric training simulating the bouncing movements requiring use of stretch- shortening cycle, fast-twitch muscle fibres and energy storage as in sprint running and jumping have been shown to substantially increase muscle power in older individuals [19].
The longitudinal design of this study and recruitment of a reasonably large cohort of elite level master athletes gave us a unique opportunity to examine the effects of aging in the absence of inactivity. Whilst there were baseline group differences in age, which has previously been shown to be linearly associated with muscle function [11, 27], our findings remained robust to additional adjustment. Sprint and power based training has been shown to improve lower limb muscle function in older inactive adults [28], and in master cyclists [29] and runners [30] when added to their usual training schedule. Therefore, whilst there may be a selection bias in the decision to participate as a master athlete, it is highly likely that regular power training contributes to observed group differences. Whilst we used a reference database collected using the same equipment and methodology, the strength of our observations could have been improved by longitudinal collection of data from non-athletes. Use of a German population reference database may limit the generalisability of our results to athletes from other countries. However, given that the focus of our study was age-related changes, we are reassured by the almost identical age-related decline in jump power identified in a large population of Japanese adults using the same assessment [31]. Whilst the mean, variance and age range were similar between the current longitudinal study and our previous cross-sectional study, we acknowledge that caution must be exercise when comparing the two types of study.
In elite master athletes, similar longitudinal changes in muscle function as assessed by jumping mechanography were observed in male and female power and endurance athletes. This is in contrast to findings of a similar study of bone strength in members of this cohort, where we observed greater maintenance of bone mineral content in male than female athletes and in power than endurance athletes [13]. Given baseline differences, this meant that power athletes maintained an advantage in lower limb peak power relative to normative reference values. The results of this study suggest that advantages in master power athletes in particular with respect to age and sex-match normative values, which includes the contribution of power training, are maintained over time. Future studies should examine whether gains in lower limb function in less active individuals are maintained with prolonged training, as indicated by the results of the current study and previous cross-sectional observations [11].
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