• The Journal of Korean Physical Therapy
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• v.31 no.2
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• pp.76-81
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• 2019

Purpose: This study examined the effects of squatting with different foot positions on the muscle activation of the vastus medialis oblique (VMO) and vastus lateralis (VL) muscles in subjects with genu varum. Methods: Thirty four subjects participated in this study. Surface electromyography was used to measure the muscle activation of the VMO and VL muscles at the knee angles ($15^{\circ}$, $60^{\circ}$) at three foot positions (internal rotation, neutral position, external rotation) during squatting. Results: Muscle activation differences at different knee angles and foot positions differed significantly between the VMO and VL muscles in both the varus and normal groups. In addition, there was a significant difference according to the knee angles with the foot in external rotation in the VMO and VL ratio. In the varus group, however, the VMO and VL ratio were significantly different only with the feet in internal rotation. In the muscle activation changes of the knee angle differences in the foot position, there was no significant difference in the varus group, but both the VMO and VL muscles were significant different in the normal group. Conclusion: In both groups, regardless of the foot position, muscle activation of the VMO and VL muscles increased with increasing knee flexion angle. In the normal group, when squatting with the feet in external rotation, the VMO and VL muscles activations increased with increasing knee angle. In the varus group, however, the foot position did not affect the VMO or VL muscle activation. This study shows that subjects with genu varum and normal subjects have different VMO and VL muscle activation patterns during squat exercises.

• PNF and Movement
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• v.21 no.2
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• pp.231-241
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• 2023

Purpose: Weakness of the vastus medialis oblique muscle (VMO), or the imbalance between VMO and vastus lateralis muscle (VL) activity, is one of the most important factors in knee joint problems. Rigid taping techniques, such as patellar inhibition taping and VL inhibition taping, are frequently used in clinical practice to treat knee joint problems. The purpose of this study was to compare the acute effect of three different types of taping (patellar inhibition taping (PIT), distal VL inhibition taping (DVLIT), and proximal VL inhibition taping (PVLIT)) on electromyography (EMG) activity of VMO, VL, and VMO:VL ratio during walking. Methods: Thirty-eight normal healthy subjects (38 males; mean age = 31.00 years) voluntarily participated in this study. EMG was applied to investigate muscle activation during walking. Repeated measures of ANOVA and one-way ANOVA compared the three different conditions (PIT, DVLIT, and PVLIT) for each variable. Results: VMO and VL activation were significantly increased after PTIT application, and VMO and VL activation were significantly decreased after DVLIT and PVLIT application. The VMO:VL ratio increased after the three types of taping application, but there were no significant differences among the three types of taping. Conclusion: Based on the results of this study, PTIT is more effective than DVLIT and PVLIT in increasing the muscle activation of the VMO and VL during walking. Also, DVLIT is more effective for increasing the VMO:VL ratio and has beneficial effects on the imbalance between VMO and VL activity.

• The Journal of Korean Physical Therapy
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• v.32 no.5
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• pp.302-306
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• 2020

Purpose: The purpose of this study was to investigate comparisons of vastus medialis (VMO) and vastus lateralis (VL) muscle activities according to different heights during drop landing in flatfooted adults. Methods: Fifteen subjects with a flat foot arch and 15 subjects with a normal feet arch were participated. Subjects performed a double limb drop landing task from 20, 40, and 60 cm heights. Surface electromyography was used to measure the muscle activities of the VMO and VL during drop landing. Results: There were significant differences of muscle activities in the VMO, VL, and the VMO and VL ratio between groups. The electromyography values of VMO, VL, and the VMO and VL ratio in the normal group were significantly greater than in the flat foot group, and muscle activities and the VMO and VL ratio significantly increased with landing heights in the both groups. Conclusion: Our results indicated that muscle activity patterns of VOM and VL in the flat foot group were lower at heights than in the normal group, so calf tightness was negative effects on balance and gait ability, so assessment of muscle activation patterns in the knee extensors should be considered during exercise and treatment of flat feet.

• PNF and Movement
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• v.21 no.1
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• pp.107-117
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• 2023

Purpose: The aim of this study is to compare the immediate effects of weight-assisting methods on vastus medialis oblique (VMO) and vastus lateralis (VL) muscle activation, on the VMO/VL muscle activation ratio, and on muscle onset time in healthy subjects when ascending stairs. Methods: Healthy participants were randomly assigned to the belt group (n = 11), hand group (n = 11), and control group (n = 11). In the belt group, a belt was wrapped around the sacrum and pulled forward with both hands, moving the center of weight forward, while ascending stairs. The hand group grasped the hips with both hands and climbed stairs, assisting their weight from the rear and moving the center of weight backward, and the control group climbed the stairs without any intervention. Results: Muscle activation of the VMO decreased significantly after the intervention in the belt and hand groups, and activation of the VL muscle in both groups showed a greater decrease than that of the VMO muscle. Further, the VMO/VL muscle activation ratio increased significantly, with an improvement shown in the order of the belt group, hand group, and control group, while muscle onset time also improved in the order of the belt group, hand group, and control group. Conclusion: The belt group demonstrated the greatest effect across all dependent variables, confirming that in clinical practice, these two weight-assisting methods are more effective interventions during stair ascent for patients with knee joint instability, pain, and imbalance than no assistance.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.20 no.1
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• pp.39-45
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• 2014

Background: The purpose of this study is to identify effects of neuro-muscular control training on vastus medialis oblique (VMO) after menisectomy of the knee. Methods: The subjects of this study are women aged 42 and 39 each who did menisectomy. Case 1 was applied quadriceps setting exercise and neuro-muscular contrlol training and case 2 was applied quadriecps setting. Intervention was done 5 times a week for 2 weeks. Measurement of muscle activity on VMO and vastus lateralis (VL) was standardized signals of each muscle to %RVC using surface EMG. Results: On comparison of exercise before and after on VMO and VL, VL activation of case 2 was increased more than case 1. Conclusion: Quadriecps-setting exercise and selective neuro-muscular control training of VMO is effective intervention on VMO activity and muscle activity ratio of VMO to VL.

• Journal of The Korean Society of Integrative Medicine
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• v.2 no.3
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• pp.49-55
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• 2014

Purpose : The purpose of this study was to investigate the effect of cross bag weight and carrying bag position type on vastus medialis oblique and vastus lateralis muscle activity ratio during step up. Method : Twenty healthy subjects participated in this study. subjects randomized performed step up with bag weight less than 15%, more than 15% of totalbody weight and without bag and carrying bag position ipsilateral and contralateral. muscle activity was measured with surface electromyography. One-way analysis of variance with repeated measures was used with a significance level of 0.05 Result : The results of this study were as follows: 1. The muscle activity ratio decreased significantly ipsilateral bag position more than 15% of body weight(p<.05). Also, the muscle activity ratio increased significantly contra lateral bag position more than 15% of body weight(p<.05). Conclusion : In conclusion, it was found that applied carrying bag position with weight on VMO,VL muscle activity ratio during step up down. Therefore carrying bag position can be used to selective activate vastus medialis oblique muscle in subjects with patellofemoral pain syndrome.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.1
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• pp.1969-1974
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• 2020

Background: Early rehabilitation after partial meniscectomy is important to recover the balance of the vastus medialis oblique and vastus lateralis and prevent pathological problems in the lower extremities and the whole body. Objective: To compare muscle activations for patients after partial meniscectomy. Design: Dual-group Pretest-Posttest Design from the Quasi-Experimental Research. Methods: Twenty participants after partial meniscectomy were recruited and were randomly divided into a Q-setting sensorimotor training group (QSMTG) and Q-setting exercise group (QSEG). Muscle activity of the vastus medialis oblique and vastus lateralis was measured before and after intervention. Results: In the two groups, the vastus medialis oblique and vastus lateralis activations increased significantly (P<.05). The Q-setting sensorimotor training group showed more increases than the Q-setting exercise group, and there were significant differences between the groups (P<.05). The activation ratio of the vastus medialis oblique and vastus lateralis had increasingly significant differences in the Q-setting sensorimotor training group (P<.05), and there were no significant differences between the groups (P>.05). Conclusion: Q-setting exercise with sensorimotor training was a useful method that improved the balance of vastus medialis oblique (VMO) and vastus lateralis (VL) activity after meniscectomy.