• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.141-148
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• 2007

Falls associated with tripping over an obstacle can be dangerous, yet little is known about the strategies used for stepping over obstacles in older Parkinson disease. The purpose of this study was to investigate the lower extremity muscle activity on the obstacle gait according to obstacle height in older Parkinson diseases. The obstacle gait of 7 older Parkinson disease was examined during a 5.0 m approach to, and while stepping over, obstacles of 0, 25, 52, and 152mm. Seven pairs of surface electrodes(Noraxon MyoResearch, USA) were attached to the right-hand side of the body to monitor the adductor longus(AL), gluteus medius(GME), gluteus maximus(GMA), biceps femoris(BF), rectus femoris(RF), gastrocnemius(GA), tibialis anterior(TA). Electromyography data were filtered using a 10Hz to 350 Hz Butterworth band-pass digital filter and normalized to the maximum value in the analyzed phases. A one-way ANOVA for repeated measures was employed for selected electromyography variables to analyze the differences of the height of four obstacles. The results showed significant differences between 0.0mm and 25, 52, and 152mm obstacle height in TA and GA activities during the second phase(swing phase). But the more increase obstacle height, the more not increase the muscle activities. This means that the Parkinson disease stepping over obstacle inefficiency. To prevent and reduce the frequency of falls, elderly Parkinson disease maintained and improved their balance, muscular strength, neuromuscular control and mobility.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.257-264
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• 2009

The purpose of this study was to investigate the lower extremity kinematics and muscle activities of adductor longus(AL), gluteus medius(GME), gluteus maximus(GMA), biceps femoris(BF), rectus femoris(RF), gastrocnemius(GA), and tibialis anterior(TA) using three dimensional and Noraxon 8 channels EMG system during turn 0, 60, 90 and 120 degrees in patients with Parkinson's disease. Seven parkinson's patients and five healthy subjects were participated in the study. Participants with Parkinson's disease demonstrated significant differences in reduction of stride length and stride width. Also, they showed ill difference in muscle activities. The strength and balance of the lower extremity muscles may help to improve cutting movement and to prevent falling in parkinson's patients.

• Journal of the Ergonomics Society of Korea
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• v.30 no.5
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• pp.605-611
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• 2011

Objective: The aim of this study was to investigate the influence of seat heights for optimizing the ingress/egress performance in the elderly people. Background: Recently elderly users have been increasing in number and the ease of ingress/egress of the vehicle becomes an important issue. Method: Seven elderly subjects participated in this study(age: 71.7${\pm}$3.6yr, height: 167.7${\pm}$5.4cm, weight: 68.1${\pm}$11.5kg). Each subject performed the sitting and rising task from comfortable seated position on the chair under the following conditions: (1) with a lumbar support and (2) without a lumbar support. We measured EMG activities of seven muscles(tibialis anterior, soleus, gastrocnemius, vastus lateralis, rectus femoris, biceps femoris and erector supinae) and ranges of motion in lower limb during sitting and standing from three different heights (400mm, 500mm and 600mm from ground) of slide-up seat. Results: Muscle activities and angular movements of hip and knee joints during standing-up and sitting-down with a high seat height(600mm) were reduced mean 30.4% in extensor muscles, 57.11% in flexor muscle, 18.74% in erector muscle and 31.0% in joints compared with a low seat height(400mm). Conclusion: Muscle activities and joint movements in hip and knee were reduced when rising/sitting from a high seat height(600mm) compared with a low seat height(400mm). Application: This study can be used to design vehicle that are easy to get in and out of by older peoples with or without impairments.

• Journal of the Ergonomics Society of Korea
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• v.28 no.1
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• pp.9-19
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• 2009

Repetitive movement, inadequate working posture, overuse of force, physical contact with sharp edge, vibration and temperature were well known risk factors of WMSDs (Work-related Musculoskeletal Disorders). Many researchers have investigated the relationship between inadequate working postures and incidences of WMSDs of the upper extremities, whereas relatively few researchers have tried to evaluate workload associated with the lower-body postures. The effects of lower-limb postures including various knee flexion angles on the subjective discomfort, heart rate and EMG of lower-limb muscles were investigated in this study. Thirty graduate students were asked to maintain thirteen different body postures, and heart rate and EMG data of five muscle groups (electro spine, biceps femoris, vastus medialis, gastrocnemius and tibialis anterior) from each posture were collected during fifteen minutes sustaining tasks. All participants were also asked to report their discomfort ratings of body parts. Results showed that high subjective discomfort ratings and heart rates were reported at the postures of knee angles of $60^{\circ}$ and $90^{\circ}$, whereas low discomfort ratings were founded at the postures of chair heights with 20cm, 40cm, and sitting with crossed legged. The change of median frequency for each muscle group during fifteen minutes tasks was investigated for each body posture to evaluate the relationship between muscle fatigue and body posture. It was found that the trends of changes of median frequency were different based on muscle group as well as lower-limb body posture from this study.

• The Journal of Korean Physical Therapy
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• v.3 no.1
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• pp.75-90
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• 1991

This study is to characterize the effects of swimming exercise on the composition of muscle fibers in rats lower limb tissue. By comparing the exercised group (4, 8 weeks) with the control group, we analyzed the difference histologically, histochemically and morphometrically. The obtained results are as follows ; 1. In the histological view, the distance between the individual muscle fibers and the muscle bundles in exercised group was shorter than that of control group. The irregular shape of sarcolemma in exercised group was observed. 2, In the histochemical view(NADH-TR. and Myosin ATPase reaction analysis), the increased populations of red and intermediate fibers were observed, whereas the white fiber was decreased. 3. In the morphometrical view, the red and intermediate fibers of tibialis anterior and gastrocnemius in exercised group were quantitatively increased, compared with control group. However, the white fiber and connective tissue in exercised group were decreased.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.9
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• pp.753-760
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• 2016

This study was undertaken to develop a bed-type cycling system of lower limbs for rehabilitation. This system consists of two modes of cycling: active and passive. Different velocity and loads are provided for improving the muscle function recovery and increasing the muscular strength. To analyze the muscle activity pattern, we measured muscular activity of lower limbs in the rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), medial gastrocnemius (MG), and soleus (SOL), while cycling in the supine position, and based on the pedaling direction. A total of 18 young and 23 elderly, healthy subjects participated in this study. Muscle activity of MG muscles was significantly different in the two age groups. This study could provide the reference data to develop cycling exercises for lower limbs during rehabilitation of the elderly patients.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.105-112
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• 2019

Objective: The main purpose of this study was to investigate the effects of wearing an ankle weight belt while performing gait in water by focusing on the effect of using ankle weights have on the gait kinematics and the muscle activities for developing optimum training strategies. Method: A total of 10 healthy male university students were recruited for the study. Each participant was instructed to perform 3 gait conditions; normal walking over ground, walking in water chest height, and walking in water chest height while using ankle weights. All walking conditions were set at control speed of $4km/h{\pm}0.05km/h$. The depth of the swimming pool was at 1.3 m, approximately chest height. The motion capture data was recorded using 6 digital cameras and the EMG was recorded using waterproof Mini Wave. From the motion capture data, the following variables were calculated for analysis; double and single support phase (s), swing phase (s), step length (%height), step rate (m/s), ankle, knee, and hip joint angles ($^{\circ}$). From the electromyography the %RVC of the lower limb muscles medial gastrocnemius, rectus femoris, erector spinae, semitendinosus, tibialis anterior, vastus lateralis oblique was calculated. Results: The results show significant differences between the gait time, and step length between the right and left leg. Additionally, the joint angular velocities and gait velocity were significantly affected by the water resistance. As expected, the use of the ankle weights increased all of the lower leg maximum muscle activities except for the lower back muscle. Conclusion: In conclusion, the ankle weights can be shown to stimulate more muscle activity during walking in chest height water and therefore, may be useful for rehabilitation purposes.

• Physical Therapy Korea
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• v.26 no.2
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• pp.16-23
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• 2019

Background: High-heeled shoes can change spinal alignment and feet movement, which leads to muscle fatigue and discomfort in lumbopelvic region, legs, and feet while walking. Objects: This study aimed to identify the effects of different shoe heel heights on the walking velocity and electromyographic (EMG) activities of the lower leg muscles during short- and long-distance walking in young females. Methods: Fifteen young females were recruited in this study. The experiments were performed with the following two different shoe heel heights: 0 cm and 7 cm. All participants underwent an electromyographic procedure to measure the activities and fatigue levels of the tibialis anterior (TA), medial gastrocnemius (MG), rectus femoris (RF), and hamstring muscles with each heel height during both short- and long-distance walking. The walking velocities were measured using the short-distance (10-m walk) and long-distance (6-min walk) walking tests. Results: Significant interaction effects were found between heel height and walking distance conditions for the EMG activities and fatigue levels of TA and MG muscles, and walking velocity (p<.05). The walking velocity and activities of the TA, MG, and RF muscles appeared to be significantly different between the 0 cm and 7 cm heel heights during both short- and long-distance walking (p<.05). Significant difference in the fatigue level of the MG muscle were found between the 0 cm and 7 cm heel heights during long-distance walking. In addition, walking velocity and the fatigue level of the MG muscle at the 7 cm heel height revealed significant differences in the comparison of short- and long-distance walking (p<.05). Conclusion: These findings indicate that higher shoe heel height leads to a decrease in the walking velocity and an increase in the activity and fatigue level of the lower leg muscles, particularly during long-distance walking.

• Korean Journal of Applied Biomechanics
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• v.31 no.3
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• pp.189-198
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• 2021

Objective: The aim of this study is to investigate the effect of biomechanical variables on gait according to indoor and outdoor environmental conditions in elderly women at risk of falling. Method: 26 elderly women aged 70 years or older, and consisted of 13 elderly people with a walking speed of less 1.0 m/s and 13 people in the fall risk group as normal groups. Depending on the purpose of the study, physical examination and psychological questionnaire were prepared, and then walking was performed in an indoor/outdoor environment, and the gait pattern, muscle activity, and plantar pressure results were compared and analyzed in the elderly females through a 2 group × 2 environment 2-way repeted ANOVA analysis. Results: The gait variable showed an interaction effect the cadence. The muscle variables showed interaction effects in the rectus femoris and tibialis anterior muscles, and the interaction effects of the plantar pressure variables were confirmed in the forefoot and midfoot of the contact area, and the midfoot of the mean pressure. Conclusion: These results indicate that both groups are exposed to falls risk when gait in an outdoor environment, but the fall risk group has a higher risk of falls in both the gait pattern, muscle activity, and plantar pressure variables. The results of this study are considered to be helpful as basic data and development of exercise programs to prevent falls.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.27 no.3
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• pp.17-24
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• 2021

Background: The study aimed to examine changes in muscle activity by measuring the Q-angle and lower extremity activity when going down the stairs, after the application of either Mulligan taping or flossing bands to patients with chronic ankle instability. Methods: A total of 19 men with chronic ankle instability in their 20s and 30s participated in the study. Participants were randomly divided into two groups: the Mulligan taping group (n = 9) and the flossing band group (n=10). The Mulligan taping group had three sets of Mulligan joint operations repeated 10 times, after which the Mulligan tape was applied. The flossing band group either performed functional activities or exercised for 2 minutes after flossing band application. After the application of either Mulligan taping or flossing bands, changes in the Q-angle and lower limb muscular activity while going down the stairs were measured and compared. Results: In the Mulligan taping group, the Q-angle significantly decreased from 13.63° to 12.7° during the step down. Similarly, the Q-angle of the flossing band group significantly decreased from 15.95° to 15.48° (p<.05). There was no difference in lower limb muscle activity between the two groups when going down the stairs. The muscle activity of the tibialis anterior significantly increased from 34.12% to 40.2%, and the difference between the two groups were statistically significant (p<.05). Conclusions: The study found that the application of Mulligan taping and flossing bands to patients with chronic ankle instability decreased the Q-angle and lower limb muscle activity when going down the stairs.