Comparison of lower limb muscle activation during downhill, level and uphill running

Article type: Research Article

Authors: Cai, Zong-Yan^a | Hsu, Cheng-Chen^b | Su, Chin-Peng^c | Lin, Chin-Fan^a | Lin, Yi-An^c | Lin, Chin-Li^d | Hsu, Mei-Chich^c

Affiliations: [a] Graduate Institute~of Physical Education, National Taiwan Sport University, Taoyuan County, Taiwan | [b] Department of Anatomy, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan | [c] Graduate Institute of Sports Science, National Taiwan Sport University, Taoyuan County, Taiwan | [d] Department of Athletic training and Health, National Taiwan Sport University, Taoyuan County, Taiwan

Note: [] Address for correspondence: Mei-Chich Hsu, Ph.D, Graduate Institute of Sports Science, National Taiwan Sport University, 250 Wenhua 1st Rd., Gueishan, Taoyuan County, Taiwan 33301. Tel.: +886 3 3283201, ext 2421; Fax: +886 3 3311843; E-mail: meichich@gmail.com

Abstract: We compared the lower limb muscle activation during uphill running (UR), level running (LR), and downhill running (DR). Eight male physically active subjects ran three slopes for 30 min at the given speed (55% vVO_{2}peak at LR), including DR (−6°), LR (0°), and UR (6°) in a random crossover, repeated measures design. Electromyographic (EMG) signals were collected from the dominated lower limb muscles: rectus femoris (RF), biceps femoris (BF), gastrocnemius (GAS), soleus, and tibialis anterior. Our results showed that greater EMG of RF was found with inclining slope (UR>LR>DR, p< 0.05); EMG of BF was greater during UR than during DR (p< 0.05); EMG of GAS differed significantly in the order: UR>DR>LR (p< 0.05). We concluded that significant differences regarding muscle activations among DR, LR, and UR were observed for the RF, BF, and GAS, especially when running opposing slopes (DR vs. UR). Additionally, when running toward uphill, the propulsive muscles, such as the RF and GAS seemed to exert more effort. In contrast, while running toward downhill, RF might work as an extensor muscle that was activated to a lesser extent, possibly due to its undergoing eccentric movement.

Keywords: Slope, electromyography, incline, eccentric exercise

DOI: 10.3233/IES-2010-0379

Journal: Isokinetics and Exercise Science, vol. 18, no. 3, pp. 163-168, 2010