Using Bilateral Functional and Anthropometric Tests to Define Symmetry in Cross-Country Skiers

• The aim of this study was to evaluate the symmetry of anthropometry and muscle function in cross-country skiers and their association to vertical jumping power. Twenty cross-country skiers were recruited (21.7 +/- 3.8 yrs, 180.6 +/- 7.6 cm, 73.2 +/- 7.6 kg). Anthropometric data was obtained using an iDXA scan. VO2max was determined using the diagonal stride technique on a ski treadmill. Bilateral functional tests for the upper and lower body were the handgrip and standing heel-rise tests. Vertical jump height and power were assessed with a counter movement jump. Percent asymmetry was calculated using a symmetry index and four absolute symmetry index levels. At a group level the upper body was more asymmetrical with regard to lean muscle mass (p = 0.022, d = 0.17) and functional strength (p = 0.019, d = 0.51) than the lower body. At an individual level the expected frequencies for absolute symmetry level indexes showed the largest deviation from zero for the heel-rise test (chi 2 = 16.97, p = 0.001), while the leg lean mass deviated the least (chi 2 = 0.42, p = 0.517). No relationships were observed between absolute symmetry level indexes of the lower body and counter movement jump performance (p > 0.05). As a group the skiers display a more asymmetrical upper body than lower body regarding muscle mass and strength. Interestingly at the individual level, despite symmetrical lean leg muscle mass the heel-rise test showed the largest asymmetry. This finding indicates a mismatch in muscle function for the lower body.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Idrottsvetenskap (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Sport and Fitness Sciences (hsv//eng)

Nyckelord

physical fitness

body composition

hand strength

heel-rise test

muscle fatigue

jump performance

triceps surae

strength

asymmetry

biomechanics

parameters

exercise

energy

Sport Sciences

Physical fitness

Idrottsvetenskap

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