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- Lundgren, Lina, 1982-, et al.
(författare)
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Normalizing stance width
- 2012
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Ingår i: Proceedings of the XIXth Congress of the International Society of Electrophysiology & Kinesiology. - Brisbane : NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health. - 9780646582283 ; , s. 221-221
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- INTRODUCTION: In previous studies, stance widths are most often determined as a percentage of shoulder width, where 70% of shoulder width is considered a narrow stance width and 140% of shoulder width is considered a wide stance width. A few studies have also normalized stance width to the width of the hips (distance between trochanters). However, there are also a possibility to normalize stance width in relation to the length of the lower extremities, since this variable might not change as much in dynamic situations and may correlate higher to the angle of the lower extremity in a frontal plane. AIM: This study aims to compare measurements of stance width when normalized to shoulder width, hip width and leg length for three different stance widths with feet attached to a board. METHOD: Motion capture (Qualisys, 16 Oqus-cameras) was used to measure 7 active male kitesurfers with their feet attached to a kiteboard (136 cm). They were 20-28 years old, in average 180 cm (SD=7 cm) and 78 kg (SD=7 kg). The subjects were standing with three different stance widths, using the same external rotation (20° bilaterally). Markers were attached to shoulders (acromion processes), knee joint lines, hips (trochanter major), heels (mid-posterior of calcaneus) and ankles (lateral and medial malleoli). Stance width was measured as the distance between the two medial ankle markers and normalized towards the distances between (1) the shoulder markers, (2) the hip markers and knee marker plus knee marker and lateral ankle marker and (3) the right and left hip marker. Furthermore, the angle of an extended lower extremity towards a vertical line in the frontal plane was measured. All measurements were done twice, and SPSS 20 was used for data analysis of correlation (Pearson’s r). RESULTS: The measured stance widths between ankles were 39.9 cm, 43.6 cm, and 48 cm (SD=1.2-1.4) for all subjects. The correlations (r) between the angle of the leg towards a vertical line and normalized stance width for the three normalization variables were: (1) 0.79, (2) 0.96 and (3) 0.93. All of the correlations were significant at a level of p>0.01. CONCLUSION: The results show that the variables hip or leg length would be preferred to use when normalizing stance width for young male athletes, standing in wide stance widths. Further studies using a greater number of subjects, more stance widths and a more heterogeneous group are suggested for the future.
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