• The Journal of Korean Physical Therapy
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• 제21권3호
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• pp.17-24
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• 2009

Purpose: The purpose of this study was to investigate the effects of a combination of isotonic (CI) technique on the balance, muscle fatigue and muscle activities of the quadriceps muscle in the paretic leg of hemiplegic patients. Method: All the subjects received a combined isotonic technique of proprioceptive neuromuscular facilitation (PNF) for about 30 minutes 3 times per week for 6 weeks. The root mean square (RMS) and mid frequency (MF) were recorded by surface electromyography (EMG)(EMG/EP system, OXFORD Medelec, UK) during maximal voluntary isometric contractions (MVIC). The balance ability was measured by a balance system (BIODEX, USA). Result: The RMS of the quadriceps muscle at post-treatment was significantly increased compared to that at pretreatment (p<0.05). Yet there was no significant difference among the three muscles. There were no significant difference in the MF of the vastus lateralis and rectus femoris between pre- and post-treatment, but the MF of the vastus medialis was significantly decreased (p<0.05). There was a significant difference in the vastus medialis and lateralis between pre- and post-treatment (p<0.05). Moreover, the overall stability index at post-treatment was significantly decreased compared to that at pre-treatment (p<0.05). But there was no significant difference between the anterior/posterior and medial/lateral stability indexes. Conclusion: The results of this study indicated that a CI technique of PNF had an effect to improve the balance and muscle activity in hemiplegic patients.

• PNF and Movement
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• 제4권1호
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• pp.9-18
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• 2006

Purpose: The purpose of this study was to investigate the effect of Proprioceptive Neuromuscular Facilitation (PNF) applied to the unilateral upper extremity on the muscle activation of contralateral lower extremity. Twenty-two healthy subjects (mean age of 23.7 years) participated in this study. Method : PNF patterns applied on the unilateral upper extremity in all subjects were the flexion/abduction/external rotation and lifting pattern. The hold and appoximation techniques for the irradiation were applied to end range of both patterns. Muscle activations in four patterns were measured in vastus medialis, tibialis anterior, rectus femoris, and gastrocnemius medial muscles of contralateral lower extremity using surface EMG system. Each EMG value in individual muscle was normalized for maximal voluntary contraction. The data were analyzed by one factor analysis of variance with repeated measure test. Result : There were significant differences in the between-subject effect (muscles) and within-subject effect (patterns) in comparison of muscle activation by application of PNF patterns (p<.05). The irradiation led to higher activation in the flexion/abduction/external rotation pattern than that of lifting pattern in all muscles (p<.05). The approximation techniques revealed more activations than these of hold technique in all muscles (p<.05). Conclusion : These results suggest that the application of PNF patterns to the unilateral upper extremity affect on the muscle activation of contralateral lower extremity and increase according to the intensity of resistance. This mechanism of contralateral effect might provide a help to the development of treatment method for the affected side and functional improvement for the patients who have damages of central nervous system or musculoskeletal problems by orthopedic injury.

• The Journal of Korean Physical Therapy
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• 제34권2호
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• pp.63-67
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• 2022

Purpose: The purpose of this study was to investigate the effect of assistance tools such as gym balls, wedges, and straps on lower extremity muscle activity and the increase in the range of motion made possible by the use of these tools. The subjects were divided into two groups: a group capable of deep-squatting (PS) and the second finding it impossible or having difficulty in performing such squats (IS). Methods: Twenty-three subjects participated in this study. Surface electromyography was used to measure the muscle activation of the rectus femoris (RF), vastus medialis (VM), and tibialis anterior (TA) muscles during deep squats, normal squats (NS), gym ball squats (GS), wedge squats (WS), and strap squats (SS). A motion analysis system was used to measure the range of motion of the knee joint during each of these exercises. Results: There was a significant difference in the RF muscle activity between the possible squat (PS) and the impossible squat (IS) groups in the GS, and there were significant differences in the RF and TA muscle activity between the groups in the WS. Both the PS group and the IS group showed a significant difference in the TA muscle activity depending on the tool used. There were also significant differences in the range of motion of the knee joints between the intervention methods using NS and those using the tools. Conclusion: In both groups, the muscle activity of the TA muscles was lower when GS, WS, and SS were performed compared to NS. In addition, compared to NS, the range of motion of the knee joint increased when the three tools were used. This study shows that the activity of the RF, VM, and TA muscles decreased and the range of motion of the knee joint increased during deep squats for both the PS and IS groups when tools were used.

• 대한통합의학회지
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• 제10권3호
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• pp.131-140
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• 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.

• 대한통합의학회지
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• 제11권4호
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• pp.27-39
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• 2023

Purpose : The aim of this study was to identify the influence of transient isokinetic exercise on cardiac autonomic modulation and muscle properties in healthy male subjects. Methods : Twenty-eight healthy males underwent isokinetic exercise of both knee joints using a Biodex systems 3 isokinetic dynamometer with an angular velocity of 60 °/sec. The changes in activity of the autonomic nervous system, as determined by heart rate variability (HRV), and in muscle properties were evaluated at three times: pre-exercise, immediately post-exercise, and 10 min post-exercise. Results : The time domain analysis of HRV revealed significant changes in the beat count and mean and minimal heart rate (HR) measured at pre-exercise, immediately post-exercise, and 10 min post-exercise (p<.001). The beat count and mean HR were markedly increased immediately post-exercise compared to pre-exercise, but then significantly decreased at 10 min post-exercise (p<.001). All parameters of the frequency domain were significantly altered by isokinetic exercise (p<.01). The low frequency/high frequency (LF/HF) ratio, as an index for the sympathovagal balance, was elevated by exercise and remained at a similarly high level at 10 min post-exercise (p<.01). The muscle properties of rectus femoris were changed as follows: Muscle tone and stiffness were significantly increased between pre-exercise and immediately post-exercise (p<.001), and between pre-exercise and at 10 min post-exercise (p<.001). Whereas, the elasticity showed no significant change. Conclusion : These results demonstrated that transient isokinetic exercise could induce changes in cardiac autonomic control and muscle properties. In particular, up-regulation of LF/HF ratio after exercise signifies thus enhanced sympathetic modulation by isokinetic exercise. Therefore, it is needed to understand the cardiovascular risks that may arise during isokinetic exercise for providing the basic evidence to establish appropriate isokinetic exercise protocols as effective rehabilitation exercises.

• 대한인간공학회지
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• 제30권2호
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• pp.357-363
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• 2011

Objective: The aim of this study is to set the design direction of the lift chair's tilting seat for development. Background: Great attention has been shown to the development of senior friendly product, because of increasing elderly population rapidly in Korea. Therefore, we need to study on sit-to-stand(STS) motion of elderly systematically for developing lift chair that is one of senior friendly products. Method: In this study, we analyzed joint moment(knee, hip) and muscle activity (Erector spinae, Rectus femoris, Vastus lateralis) on STS motion of elderly(female, 60~70: 7) and young people(female, 20~30: 7) using 3 dimension motion capture camera, force plate, wireless EMG. Results: The results of muscle activity showed a similar trend but the results of joint moment were a lot of differences between the young and the elderly. Conclusion: The results of knee joint moment suggest the angle(10~30deg)-adjustable seat that can be better than to find the optimal seat's angle. Application: The method and results of this study are expected to develop senior friendly product and verification as well as be available to various application.

• Archives of Reconstructive Microsurgery
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• 제14권1호
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• pp.24-30
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• 2005

Thigh perforator flaps are used popularly, because they have a small thickness, a long vascular pedicle and a low rate of donor site morbidity. Among thigh perforator flaps, anterolateral thigh perforator flaps are generally used, but it is not easy to dissect the vastus lateralis muscle to find the vasuclar pedicle. The authors have planed 11 anteromedial thigh perforator flaps that have septocutaneous perforators. We were able to find anteromedial thigh perforators in 8 cases(72.7%). The perforators originated from the medial descending branch of the lateral circumflex femoral artery in 2 cases and a branch to the rectus femoris muscle in 6 cases. Of this type of surgery, 7 flaps survived. However, 1 flap failed because of arterial insufficiency. We believe the anteromedial thigh perforator flap is a good option when the thigh region is decided as a donor site, but surgeons should keep in mind that the perforator of anteromedial thigh flap may be absent.

• The Journal of Korean Physical Therapy
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• 제20권1호
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• pp.11-16
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• 2008

Purpose: This study was undertaken to compare the signal characteristics of surface electromyography (EMG) between progressive resistive increase exercise (PRIE) and progressive resistive decrease exercise (PRDE). Methods: Forty healthy male subjects were randomly assigned to either the PRIE group or the PRDE group. Subjects participated in the PRIE and PRDE methods, with 10 RM for each subject. EMG activity was recorded from the rectus femoris muscle. Outcome data were collected for both groups pre-exercise, immediately post-exercise, then at 5 and 10 minutes post-exercise. Repeated measures 2-way ANOVA was used to determine the statistical difference of the root mean square (RMS) in EMG activity. Results: We showed that RMS values, when compared with pre-exercise, were decreased immediately after exercise and were increased at 5 and 10 minutes after exercise (p<0.05). The RMS values were not significantly different between the two groups (p>0.05). Conclusion: These results can indicate that both the PRIE and PRDE protocols will be improve strength with equivalent efficacy. Further studies are needed to address exercise duration, frequency of exercise sessions, and rest times than the PRIE and PRDE protocols with regard to the changes in strength improvement without a large amount of muscle fatigue.

• Safety and Health at Work
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• 제13권3호
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• pp.315-325
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• 2022

Background: Firefighters are required to carry self-contained breathing apparatus (SCBA), which increases the risk of musculoskeletal disorders. This study assessed the newly recruited firefighters' internal forces and potential musculoskeletal disorders when carrying SCBA. The effects of SCBA strap lengths were also evaluated. Methods: Kinematic parameters of twelve male subjects running in a control condition with no SCBA equipped and three varying-strapped SCBAs were measured using 3D inertial motion capture. Subsequently, motion data and predicted ground reaction force were inputted for subject-specific musculoskeletal modeling to estimate joint and muscle forces. Results: The knee was exposed to the highest internal force when carrying SCBA, followed by the rectus femoris and hip, while the shoulder had the lowest force compared to the no-SCBA condition. Our model also revealed that adjusting SCBA straps length was an efficient strategy to influence the force that occurred at the lumbar spine, hip, and knee regions. Grey relation analysis indicated that the deviation of the center of mass, step length, and knee flexion-extension angle could be used as the predictor of musculoskeletal disorders. Conclusion: The finding suggested that the training of the newly recruits focuses on the coordinated movement of muscle and joints in the lower limb. The strap lengths around 98-105 cm were also recommended. The findings are expected to provide injury interventions to enhance the occupational health and safety of the newly recruited firefighters.

• 대한물리의학회지
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• 제16권2호
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• pp.1-8
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• 2021

PURPOSE: This study examined the effects of changes in the head direction (forward, upward 10° and downward 10°) on the quadriceps, center of pressure (COP), and foot pressure during squat exercises. The aim was to determine if the head direction could better activate the quadriceps muscle and provide a safer and stable squat posture during squat exercise. METHODS: Fifteen healthy college students were asked to stand on a Zebris, and three electrodes for sEMG were attached to their vastus medialis oblique (VMO), vastus lateralis (VL), and rectus femoris (RF) muscles. The participants then performed squatting exercises under three head directions (forward, upward 10°, and downward 10°). Surface electrodes were then used to record the EMG data during exercise. The Zebris FDM-SX was used to measure the foot pressure and COP of the participants. RESULTS: In squat exercise, the upward head direction group showed significantly higher VL activation than the downward head direction group (p < .05). The upward head direction group showed a significant backward change in the deviation of the COP than the downward and forward groups (p < .05). The upward head direction group showed a significant decrease in forefoot pressure than the downward and forward groups (p < .05) and an increase in the hindfoot pressure compared to the downward and forward groups (p < .05). CONCLUSION: The head direction upward in squat exercise has a positive effect on the quadriceps.