A review of strength & endurance research in rock climbing - page 2 The angle of the wall surface has been shown to be an important influence on the physiological demand placed on the body due to climbing. Noé et al. (2001) examined the biomechanical constraints of static climbing positions at different angles (vertical and 10 degrees overhanging). When vertical and overhanging quadrupedia were compared there was a large shift in the distribution of the supporting forces to the upper limbs, from 43% to 62% of body weight supported by the upper limbs in the vertical and overhanging positions respectively. Given that rock climbs can feature angles of up to 90 degrees beyond vertical, this magnitude of shift appears remarkable and certainly explains the physiological findings (described below) of performance studies which showed much greater energy expenditure and lactate production with only small increases in angle beyond vertical (Watts et al., 1998). Unfortunately this is the only study to compare supporting force distribution at different angles. Further studies examining a greater range of wall angles would give further insight into the dependence on the upper limbs for support at overhanging angles. Finger flexor strength has been extensively measured in trained climbers by a number of studies. The conclusion of these studies appears to be that trained climbers have higher finger strength compared to controls, although methodological differences have provided varying results (Sheel, 2004). An early study by Watts et al. (1993) observed no differences in absolute values of hand-grip strength measured by hand-grip dynamometry in world class climbers and controls. It was suggested that climbers may not need high grip strength per se. Rather, strength to mass ratio was thought to be a more important variable and this was significantly higher in climbers (due to low body mass). Several later studies have measured hand-grip strength, some observing no differences in absolute forces between elite climbers and recreational or non-climbers (Ferguson and Brown, 1997; Watts et al., 2003) and others observing that climbers have higher grip strength (Bollen and Cutts, 1993; Grant et al., 1996, 2001). Grant et al. (1996) recognised that grip strength dynamometry might not provide an accurate assessment of the type of strength required in rock climbing, and developed a climbing specific device for measuring finger strength that simulated more closely the grip styles used on climbing holds (Schweizer, 2001) (Fig. 1, 2). All subsequent studies using this type of grip specific measurement have recorded higher finger strength in trained climbers (Grant et al., 1996, 2001, 2003; Quaine et al., 2003; MacLeod et al., unpublished data; Reid et al., unpublished data). Although climbing moves often involve hanging or moving underneath horizontally aligned finger edges, the types of moves and positions experienced in climbing are extremely varied and it seems likely that some may involve a force requirement greater than that needed to support the body in the vertical direction (such as using ‘undercut’ holds) (Goddard and Neumann, 1993; Sagar, 2001). This view would challenge Watts’ suggestion that climbers do not need to produce large absolute forces. Unfortunately no biomechanical analysis has been carried out on a range of climbing positions/movements to date, in order to determine the supporting force requirements of climbing positions.
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