The Effects Of Height On Smoothness Of Gait In Adolescent Athletes

Abstract

PURPOSE:To determine the relationship between height and changes in motion, using the harmonic ratio (HR) of adolescent athletes during walking before and after fatiguing exercises. METHODS: Participants were 21 females (mean 12.05 yrs, range 9-15 yrs) and 32 males (mean 13.46 yrs, range 10-16 yrs) athletes. Athletes completed a treadmill warm-up, during which their self-reported preferred walking speed (PWS) and walk-to-run transition speed were determined. These were used to calculate speeds slower (SWS), and faster than PWS (FWS). Subsequently, athletes completed two 9-minute treadmill walking trials (pre- and post-fatigue), consisting of 3-minute segments at each of the three speeds (SWS, PWS, FWS). Between the two trials, subjects completed a 10-minute series of exercises to induce lower extremity muscle fatigue. During walking, acceleration was measured in three planes of motion: Anterior-Posterior (AP), Medio-Lateral (ML), and Vertical (V). HR of acceleration, an indicator of smoothness of gait, was calculated for AP, ML, and V. RESULTS:: In pre-fatigue walking, there was a significant positive relationship between height and HR for males (R2 = 0.336, p = 0.001). Females had no significant relationship in pre-fatigue (R2 = 0.024, p = 0.56). In post-fatigue walking there was significant interaction by sex, with males retaining a significant positive association between height and HR (R2 = 0.265, p = 0.01) and females showing a significant negative association between height and HR (R2 = 0.393, p = 0.007). This relationship was not seen at PWS or FWS. CONCLUSIONS: Following fatiguing conditions, adolescent female athletes showed a greater change in the HR of the upper trunk in the vertical direction compared to males. Taller females had significantly decreased smoothness in vertical trunk motion compared to shorter females, while taller males had increased smoothness in vertical trunk motion in both pre- and post-fatigue conditions compared to shorter males.