• Korean Journal of Applied Biomechanics
• /
• v.16 no.1
• /
• pp.19-30
• /
• 2006

The purpose of this study was to examine the effect of foot orthotics on the overall comfort and muscle activity during running. The subjects were 10 members from the joggers' club which consisted of 2 women and 8 men. These individuals ran on the treadmill by 4.0m/s speed with and without the custom foot orthotics. The data concerning the overall comfort was collected by a questionairre that examined the overall comfort, heel cushioning, forefoot cushioning, medio-lateral control, arch height, heel cup fit, shoe heel width, forefoot width, and shoe length The MegaWin ver. 2.1(Mega Electronics lid, Ma. Finland) was used to gain electromyography signals of the muscle activity; Tibialis anterior, medial gastronemius, lateral gastronemius, vastus lateralis, vastus medialis, biceps femoris, and rectus femoris were measured. The results of the study were as follows. 1. During running the overall comfort was higher for the foot arthotic condition than the nonorthotic condition. Among the inquiries the overall comfort showed the biggest difference comparing the two conditions. and the shoe heel width showed the highest score for contort. 2 The muscle activity of the biceps femoris, and vastus lateralis in the stance period decreased. due to the foot orthotics. The muscle activity of the vastus medialis in the swing period also decreased and the muscle activity tibialis anterior in the stance and swing stance decreased as well During running, orthotics showed positive result in foot comfort. The foot comfort related to decreased stress, muscle activity, and foot arch strain. Overall comfort and the adequate decrease of muscle activity were associated with injury prevention and the best method to prevent injury semms to be the maintenance of foot comfort.

• The Journal of the Society of Stroke on Korean Medicine
• /
• v.14 no.1
• /
• pp.102-106
• /
• 2013

■ Objectives The purpose of the this study was to investigate organization change(pennation angle) of lower extremity muscle in elderly with knee osteoarthritis through ultrasonic image. Also, we examined organizational change of muscle was by influenced after total knee replacement(TKR). ■ Methods Rectus femoris image was taken at 50% of the distance between the anterior superior iliac spine and the superior border of the patella. Vastus medialis image was taken at the most distal insertion level of vastus medialis on the medial border of the patella. measurements included the most distal insertion level of the vastus medialis on the medial border of the patella. ■ Results Change of pennation angle in rectus femoris showed decrease from 5.11° in preoperation to 4.29° in 1 week after operation. Change of pennation angle in vastus medialis showed decrease from 6.94° in preoperation to 5.76° in 1 week after operation. ■ Conclusion We consider decrease of pennation angle after total knee replacement in this study was casued by organizational change of muscle and this pennation angle was influenced force created by muscle. Therefore, we thinks that this pennation angle through ultrasonic image will be available to plane individual muscle exercise program and to confirm muscle mass by muscle strength training.

• PNF and Movement
• /
• v.15 no.3
• /
• pp.303-310
• /
• 2017

Purpose: This study observed the activity of trunk and lower limb muscles during a modified bridging exercise with various weight loads. Methods: The participants in this study consisted of 15 male adults. The muscle activity of the elector spinae, rectus abdominis, gluteus maximus, gluteus medius, vastus medialis, vastus lateralis, tibialis anterior, and soleus muscles was measured with an EMG-8 system during a modified bridging exercise performed with various weight loads (indicated as percentage of body weight). Differences in muscle activity during the bridging exercise according to the weight load applied were analyzed using a one-way ANOVA, and post hoc analysis was performed using LSD. Statistical significance was accepted at a p-level of 0.05. Results: When the subjects performed the modified bridging exercise with various weight loads, the muscle activity of the gluteus maximus and vastus medialis peaked at a load of 0.5%. The activity of the gluteus medius showed a remarkable difference when the modified bridging exercise was performed at loads of 0% and 0.5%, 0% and 1%. In addition, the activity of the vastus medialis showed a remarkable difference between modified bridging exercises performed at a load of 0% and that performed at a load of 0.5%. Conclusion: The results suggest that performing modified bridging exercises with a load of 0.5% of body weight results in significant differences in the activity of the gluteus medius and vastus medialis muscles. Thus, it is suggested that performing the modified bridging exercise at 0.5% of body weight may selectively strengthen the gluteus medius and vastus medialis muscles.

• Korean Journal of Applied Biomechanics
• /
• v.21 no.4
• /
• pp.467-477
• /
• 2011

This study was performed to investigate the effects of tibial rotation while going up stair on muscle activity of vastus medialis oblique and vastus lateralis, and on patellar displacement. The subjects included 30 people (male: 15; female: 15) who were randomly assigned to the tibial internal-rotation, neutral-rotation, and external-rotation groups. The subjects went up the stair while performing the assigned rotations, and the rotation of the hip and the displacement of the patella were measured using a 3D motion analyzer. In addition, the maximum voluntary isometric contraction (MVIC) of the vastus medialis oblique and vastus lateralis were measured using surface electromyogram. On the tibial internal rotation, the hip rotation significantly appeared in the same direction and so did on the tibial neutral and external rotations(p<.001). Although the MVIC of the vastus medialis oblique and vastus lateralis did not significantly differ by tibial rotation during the stair ascent, the MVIC of the vastus medialis oblique was higher than that of the vastus lateralis during the internal and neutral rotations (p<.05). In addition, during the stair ascent, the displacement of the patella was more significant during the tibial external rotation than during the tibial internal and neutral rotations(p<.001). Thus, patients with patellofemoral pain are required to be considered the effects of tibial rotation for their rehabilitation.

• Journal of the Korean Society of Physical Medicine
• /
• v.15 no.2
• /
• pp.49-56
• /
• 2020

PURPOSE: This study examined the difference in muscle activity of the trunk and legs during flat walking with or without an abdominal drawing-in maneuver. METHODS: This study was conducted on 15 healthy males and eight females who were attending D University in Busan. This experiment was conducted after 15 minutes of abdominal drawing-in training using a pressure biofeedback unit before the experiment, and the difference in the muscle activity of the trunk and legs during flat walking with or without an abdominal drawing-in technique was investigated. Surface electromyography was used, and the electrode attachment site was the right sternocleidomastoid muscle, splenius capitis muscle, rectus abdominis muscle, external abdominal oblique muscle, transverse abdominis muscle, erector spinae muscle, vastus medialis muscle, and vastus lateralis muscle (TM DTS, Noraxon, USA). The data were analyzed statistically using a paired t-test on SPSS version 18.0 (IBM). RESULTS: The muscle activity of the rectus abdominis muscle, external abdominal oblique muscle, transverse abdominis muscle, vastus medialis muscle were increased significantly and maintained more than walking without maintaining an abdominal drawing-in maneuver (p < .05). Moreover, muscle activity of the erector spinae muscle was decreased significantly and maintained more than walking without maintaining an abdominal drawing-in maneuver (p < .05). CONCLUSION: Maintaining an abdominal drawing-in maneuver during flat walking is more effective during walking training.

• Journal of The Korean Society of Integrative Medicine
• /
• v.10 no.3
• /
• pp.131-140
• /
• 2022

Purpose : Although many studies have explored the effect of seating side angles on the spinal curve and surrounding muscles during seating, only a few studies have investigated the effect of different seating face angles on different lower limb and deep trunk muscles. Therefore, this study investigated the effects of seating surface angles (0 degrees, 10 degree anterior, and 10 degree rear) on lower extremity and deep trunk muscles in healthy adults. Methods : Thirty people were asked to sit once on each seating surface three times during the day, and their muscle thicknesses were measured by ultrasound while sitting. The method of sitting was the same when sitting on the three seating surfaces. Results : From the comparison results of the muscle thicknesses according to the seating surface angles, a significant difference existed in the muscle thicknesses of the vastus medialis, vastus medialis oblique, vastus intermedius, soleus and gastrocnemius (p<.05). However, no significant difference was found in the transversus abdominis, internal obliques, rectus femoris and vastus lateralis (p>.05). Conclusion : Our findings revealed that the lower back load decreases, the leg load increases, and the legs specific muscles are affected as the body tilts forward when sitting on the seating surface inclined forward. Therefore, it is possible to suggest a forwardly inclined seating surface that reduces lower back loads and utilizes the posture-maintaining muscles of the legs when sitting in a person with a poor sitting posture or lower back pain at ordinary times.

• The Journal of Korean Physical Therapy
• /
• v.22 no.2
• /
• pp.39-46
• /
• 2010

Purpose: This study was designed to determine whether General Coordinative Manipulation (GCM) Intervention Models have effects on the balanced restoration of asymmetrical muscles in the extremities. Methods: Fifty-nine healthy subjects (1st hypothesis: n=40, 2nd hypothesis: n=19) participated in studies using the two GCM intervention models. Subjects were studied 2 times a week for 3 weeks. Electromyography (EMG) was used to measure muscle activity, and measurements were performed before and after the application of the each intervention model. Results: Hypothesis 1: GCM Intervention, which coordinates flexion types of muscle contractions of the upper extremity and extension types of muscle contractions of the lower extremity (excluding self-care) is effective for treating shows the treatment in efficiency on more than two 2 of 3 muscles (vastus medialis, gastrocnemius medial, and deltoid middle) and the effects affects on more than 3 types of 4 body types (Vastus medialis, Gastrocnemius medial of Body type III, p<0.05). GCM body type was classified by the relative tilting of right and left scapulars and iliums into four groups. Hypothesis 2: GCM Intervention, which coordinates flexion types of muscle contractions of the lower extremity and extension types of muscle contractions of the upper extremity (excluding self-care) is effective for treating more than two 2 of 3 muscles (vastus medialis, gastrocnemius medial, and deltoid middle) and the effects affects on more than 2 types of 3 body types (p>0.05).

• Korean Journal of Applied Biomechanics
• /
• v.19 no.3
• /
• pp.557-566
• /
• 2009

This study was to investigate gender differences in muscle activities on tibialis anterior muscle, gastrocnemius and vastus medialis obliqus and outside and prime mover, antagonist and assistance mover during golf drive swing by electromyography. Ten healthy professional golfers (KPGA(n)=5, KLPGA(n)=5) volunteered in this experiment. All statistical analyses were performed using SPSS. Statistical differences were assess using t-test (p<.05). The conclusion of this study was as following. Muscle dislocation of differences, according to gender, was the highest in case of males in right side of gastrocnemius with the section from the address to the backswing of top and was the highest in case of females in tibialis anterior muscle. Results also show that prime mover was left side of low muscle in case of male with all the sections and situations and is right side low muscle in case of female. These results were significant differences. In case of males, it was though that primer mover was left side of tibialis anterior muscle with moving weight from backswing of top till the address section. In case of females, primer movers were right side of vastus medialis obliqus and tibialis anterior muscle with pushing action form the right knee to the left knee. Therefore, if they try to do the training be able to development right side of vastus medialis obliqus and tibialis anterior muscle in case of females and left side of vastus medialis obliqus and tibialis anterior muscle in case of males, it is consider that golfers' distance and direction will get better.

• PNF and Movement
• /
• v.19 no.2
• /
• pp.153-162
• /
• 2021

Purpose: The purpose of this study was to investigate the difference in the dynamic balance and leg muscle activity of adults in their 20s with or without shoes. Methods: In this study, seven male and 11 female university students in their 20s were randomized to determine the order of being with or without shoes, and the dominant foot was supported on the central platform of dynamic balance according to the order procedure. Using the opposite foot, the distance of leg stretching in the anterior, posterior medial, and posterior lateral directions and the muscle activity of the supporting leg were measured. Muscle activity measurement sites were attached to the dominant vastus medialis oblique muscle, vastus lateral oblique muscle, tibialis anterior muscle, peroneus longus muscle, and lateral gastrocnemius muscle. Results: As a result of this study, the distance of leg stretching was significantly increased in the anterior, posterior medial, and posterior lateral directions when barefoot rather than when wearing shoes (p < 0.05). The muscle activity of the vastus medial and lateral oblique muscles was significantly increased in all three directions when barefoot rather than when wearing shoes (p < 0.05). The muscle activity of the tibialis anterior was significantly increased in the anterior direction when barefoot (p < 0.05), the peroneus longus muscle was significantly increased when it was barefoot in the posterior medial direction (p < 0.05), and the lateral gastrocnemius muscle activity significantly increased when barefoot in the posterior direction (p < 0.05). Conclusion: The movement of the legs is freed when barefoot as compared to when wearing shoes, and being barefoot can effectively activate muscle activity and improve balance ability.

• Physical Therapy Korea
• /
• v.12 no.2
• /
• pp.11-19
• /
• 2005

Patellofemoral pain syndrome (PFPS) is often attributed to malalignment and maltracking of patella within the patellofemoral joint. Most exercise for PFPS has focused on selectively strengthening the vastus medialis oblique muscle (VMO). This study was designed to identify the effect of medial, lateral wedge and difference of Quadriceps angle (Q-angle) on vastus medialis oblique/vastus lateralis muscle (VL) activity ratios. The subjects were twenty young adult males who had not experienced any knee injury. They were asked to perform isometric contraction exercises in three postures using medial and lateral wedge. The EMG activity of the VL and VMO were recorded in three postures by surface electrodes and normalized by %MVC values derived from seated, isometric knee extensions. The normalized EMG activity levels (%MVC) of the VL and VMO for the three postures of the lower extremities were compared using 2-way repeated measures ANOVA with 1 between-subject factor (group), and 1 within-subject factor (wedge). Results of repeated measures of ANOVA's revealed that the medial wedge isometric contraction exercise produced significantly greater EMG activity of VMO/VL ratios in Group I (Q-angle $18^{\circ}$ or less) (p<.05). But, the medial wedge isometric contraction exercise was no significant difference of VMO/VL ratios in Group II (Q-angle $19^{\circ}$ or more) (p>.05). These results have important implications for selective VMO muscle strengthening exercises in PFPS patients.