Lower Extremity Muscle Co-contraction Characters During Different Plane of Lunges in Healthy Individuals

• Main Authors: Dai, Yong-Xuan, 戴詠璇
• Other Authors: Lee, Heng-Ju
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/8j6aq2

碩士 === 國立臺灣師範大學 === 體育學系 === 106 === Lunge exercises were widely been used to strengthen the quadriceps and hamstrings muscles, and co-activation of the quadriceps and hamstrings could affect stabilization of the knee and movement. Therefore, identifying lunges that facilitate balanced activation of the quadriceps and hamstrings might be beneficial in knee joint injury prevention and stabilization of movement. Purpose: this study was to examine the co-activation of the quadriceps and hamstrings during multiple planes of lunges. Methods: There were twelve healthy collegiate individuals volunteered to participate in this study (age 20.7 ± 1.4 yrs, height 174.6 ± 3.9 cm, weight 68.8 ± 8.5 kg). Surface EMG signals were collected by five Delsys Trigno sensors at 1000 Hz. Sensors were placed on rectus femoris, vastus lateralis, vastus medialis, biceps femoris, semitendinosus of the dominant leg. One-way ANOVA with repeated measures was used to exam the differences in biomechanical parameters of the lower limb muscle activations during multiple planes of lunges. Results: The muscle co-activation ratios (Q:H) are calculated as mean quadriceps activation divided by mean hamstring activations during movement. The quadriceps activation and knee extensor moment of side lunge was greater than other two lunge exercises, the hamstrings activation of reverse lunge during descending phase and ascending was greater than other two lunge, The Q:H ratios of reverse lunge was smaller than other two lunge exercises. Discussion: A resulting Q:H ratio equal or close to 1.0 indicates a more balanced muscle activation. The smaller Q:H ratio (close to 1.0) during descending phase of reverse lunge could be peculated that reverse lunge was a more hamstring dominant exercise than other two lunge exercises. A significant greater Q:H ratio of side lunges could indicate that a stronger quadriceps muscle activation was existed and tended to lead to greater stresses on the knee joints.