UPPER BODY MUSCLE EXCITATION DURING SPRINTING
Victoria Ann Conn, Eileen Wheelen, David Elmer, Jessica Washington. Berry College, Mount Berry, GA.
BACKGROUND: Adequate arm swing from the shoulder girdle muscle group is vital in technique during acceleration and maximal speed of sprinting phases. Arm swing can alter lower extremity muscle activation and stride efficiency. Due to the lack of literature involving the effects of upper body muscle activity on sprint acceleration, the purpose of this study was to examine electromyography (EMG) of the shoulder girdle to determine muscle contribution in sprint propulsion. METHODS: Seven participants (20.86 ±0.90 yrs.; 1.72±0.09 m; 71.67±14.16 kg) were recruited to participate. Surface EMG was used to measure peak and mean activation of the triceps brachii, biceps brachii, upper trapezius, and anterior deltoid during 40-m sprints on an outdoor track under two conditions: split starts and block starts. Muscle activity was recorded as a percentage of maximum voluntary isometric contraction (%MVIC) during three phases of each sprint: 0-10 m, 10-30 m, and 30-40 m. RESULTS: A within-subjects repeated-measures ANOVA was executed to determine differences in mean and peak muscle activation across condition and sprint phase. A statistically significant main effect of phase was revealed for mean activation (F2,12=6.58, p=.01). Post-hoc pairwise comparisons showed a statistically significant decrease in mean muscle activation between phase one and three (p=.03) and between phases two and three (p=.02). Additionally, a statistically significant main effect of phase was revealed for peak activation (F2,12=10.63, p<.01). Post-hoc pairwise comparisons showed a statistically significant decrease in peak muscle activation between phase one and two (p=.02), phase one and three (p=.02), and phase two and three (p=.02). There were no significant differences in mean (F3,18=0.93, p=0.50) or peak (F3,18=1.74, p=0.30) activation between the four muscles analyzed or between split and block start conditions (F1,6=0.16, p=0.70), and no significant interaction effects were detected. CONCLUSIONS: Initial excitation of the shoulder girdle muscles during phase one of the sprint may account for both the significant peak and mean activations, however, shoulder muscle excitation during phases two and three reaches a steady state of activation. Therefore, muscle activation of the shoulder girdle may contribute most to propulsion during acceleration of the sprint and minimally so during maintenance of speed.
Conn, VA; Wheelen, E; Elmer, D; and Washington, J
"UPPER BODY MUSCLE EXCITATION DURING SPRINTING,"
International Journal of Exercise Science: Conference Proceedings: Vol. 16:
1, Article 186.
Available at: https://digitalcommons.wku.edu/ijesab/vol16/iss1/186