• Journal of Mechanical Science and Technology
• /
• v.20 no.8
• /
• pp.1183-1194
• /
• 2006

The aim of this study was to identify the characteristics of the flexion withdrawal reflex modulated by the hip angle and hip movement in spinal cord injury (SCI). The influence of the hip position and passive movement were tested in 6 subjects with chronic SCI. Each subject placed in a supine position and lower leg was fixed with the knee at 5 -45 degree flexion and the ankle at 25-40 degree plantar flexion. A train of 10 stimulus pulses were applied at 200 Hz to the skin of the medial arch to trigger flexion reflexes. From results of the regression analysis, static properties of normalized muscle activation of flexor muscles have the linear relationship with respect to hip angle (P< 0.05). In order to verify the neural contribution of flexion reflex, we compared the static and dynamic gains of estimated muscle activations with measured EMG of ankle flexor muscle. Form this study, we postulate that the torque and muscle response of flexion withdrawal reflex have linear relationship with hip angle and angular velocity.

• Physical Therapy Korea
• /
• v.23 no.1
• /
• pp.80-86
• /
• 2016

Background: Prone hip extension (PHE) can be performed to measure the lumbopelvic motor patterns and motions. Imbalances in lumbopelvic muscle activity and muscle weakness can result in instability including pain in lumbopelvic region. The posterior oblique sling (POS) muscles contribute to dynamic lumbopelvic stability. In addition, POS are anatomically aligned with the trapezius muscle group according to shoulder positions. Objects: This study compared the electromyography (EMG) activity of POS and pelvic compensations during PHE with and without pre-activation of lower trapezius muscle (lowT). Methods: Sixteen healthy males were recruited. PHE was performed in randomized order: PHE with and without lowT pre-activation. Surface EMG signals were recorded for biceps femoris (BF), gluteus maximus (GM) (ipsilateral), lumbar multifidus (MF) (bilateral), and the lowT (contralateral). An electromagnetic tracking motion analysis was used to measure the angle of pelvic rotation and anterior tilting. Results: The ipsilateral GM and bilateral MF EMG amplitudes were greater during PHE with lowT pre-activation compared to PHE without lowT pre-activation (p<.05). The BF amplitude during PHE without lowT pre-activation was significantly greater than that during PHE with lowT pre-activation (p<.05). The angles of pelvic rotation and anterior tilting during PHE with lowT pre-activation were significantly smaller compared to PHE without lowT pre-activation (p<.05). Conclusion: PHE with lowT pre-activation, which is aligned with the POS, showed more increased MF and GM muscular activity with smaller lumbopelvic compensations in rotation and anterior tilting compared to PHE without lowT pre-activation.

• Journal of International Academy of Physical Therapy Research
• /
• v.2 no.1
• /
• pp.237-243
• /
• 2011

This study was to examine on the respiratory variables, heart rate and muscle activity between the static recovery and dynamic recovery after progressive resistance exercise to maximal point. Subjects were 15 students enrolled in N University. All were tested two times (static recovery and dynamic recovery) and were requested to perform a walking on a treadmill after progressive resistance exercise to maximal point. Electromyography(EMG) was used to monitor the muscle activity(TA: Tibialis Anterior, MG: Medial Gastrocnemius) during gait. CPEX-1 was used to measure the respiratory variables and heart rate. The dynamic recovery group was shown the significant lower heart rate than that of static recovery group at during gait. Respiratory rate showed statistically a significant difference. Electromyography(RMS, root mean square) showed a non-significant difference. But the dynamic recovery group of muscle activity was found highly in TA and MG. This study indicated that the dynamic recovery method evidenced more faster than the static recovery method. And this type of dynamic rest by walking can be a help of recovery after exercise.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.18 no.2
• /
• pp.41-47
• /
• 2012

Background: This study was designed to investigate the correlation between electromyography (EMG) activities in the vastus medialis oblique (VMO) vs vastus lateralis (VL) activity ratio and the valgus collapse knee position while stepping down. Methods: Twenty healthy women volunteered to participate in this study. We measured the frontal-plane projections of the knee valgus angle, knee valgus distance, and hip adduction angle by using a digital camcorder. After 3 repetitions of the step down (dominant side) exercise, the findings of the static and dynamic phases were analyzed. EMG activities data of the VMO:VL activity ratio were recorded during the step down exercise and were normalized to the maximal voluntary isometric contraction (MVIC) of the quadriceps. A paired t-test was used to compare the findings of the static and dynamic phases. We analyzed the Spearman's rank order correlation coefficient between the and VMO:VL ratio. Results: Hip adduction angle, knee valgus angle, VMO activity, VL activity, VMO:VL activity ratio were statistically higher in the dynamic phase than in the static phase (p<.05). Frontal-plane projections of knee valgus angle were significantly correlated with hip adduction angle (r=.459, p<.05) and knee valgus distance (r=.505, p<.05). However, the EMG activity ratio of the VMO and the VL did not show a significant change during step down exercise with respect to hip adduction angle (p=.875), knee valgus angle (p=.618), and knee valgus distance (p=.701). Conclusion: The results from this study indicate that frontal-plane projections of knee valgus angle were associated with hip adduction angle and knee valgus distance. On the basis of these results, the knee valgus distance may be used to determine the valgus collapse knee position while stepping down.

• Journal of International Academy of Physical Therapy Research
• /
• v.9 no.2
• /
• pp.1447-1454
• /
• 2018

The objective of this study was to investigate the dynamic neural mobilization program on the changes in muscle activity and nerve conduction velocity (NVC) in stroke patients. The participants were sampled and randomly divided into experimental group I (n=12) who underwent arm neural mobilization and experimental group II (n=13) who underwent arm dynamic neural mobilization. As the pretest, peripheral NVC of the radial, median, and ulnar nerves were measured using the Viking Quest; the biceps brachii, brachioradialis, flexor carpi radialis, and extensor carpi radialis activities were measured with sEMG. Each intervention program consisted of 10 trials per set and three sets per session. The intervention programs were performed once daily for four weeks (four days/week). Posttest measurements were taken equally as the pretest measurements. Significant differences in peripheral NVC in all sections of the radial and median nerves and wristbelow elbow and below elbow-above elbow areas of the ulnar nerve, as well as in muscle activity of all muscles except the biceps brachii. These findings indicate that dynamic neural mobilization was effective in increasing peripheral NVC and altering the muscle activity.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.05a
• /
• pp.289-289
• /
• 2004

보행 시작(Gait Initiation)은 정적 기립상태에서 출발하여 일정한 보행주기가 반복되기 전까지의 과정을 말한다. 이러한 보행의 시작은 아주 짧은 시간에 무의식적으로 이루어지는 움직이지만, 신경계의 조절 근육의 작용 및 생체역학적인 힘의 복합적인 통합에 의해 이루어진다. 노인의 낙상은 보행시작의 과정에 있어서 주로 신체노화와 질병으로 인한 균형 조절능력의 감소를 가장 큰 요인으로 보고 있다. 하지만 지금까지는 주로 운동역학과 동적 근전도에 대한 연구가 주류를 이루었다.(중략)

• Physical Therapy Korea
• /
• v.11 no.4
• /
• pp.19-29
• /
• 2004

Many muscles of the trunk and hip are capable of contributing to the stabilization and protection of the lumbar spine. To have optimal effectiveness, a training program should include dynamic back/stomach/hip exercises. This study was designed to assess the L5 level paraspinal, external abdominal oblique, and gluteus maximus muscle activities during various low back stabilization exercises. Participants were 26 healthy adults (13 males, 13 Females), aged 21 to 28 years. The surface electromyography (EMG) was recorded from the L5 level paraspinal, external abdominal oblique, and gluteus maximus muscles. The recorded signal was averaged and normalized to the maximal electromyographic amplitude obtained during the maximal voluntary contraction. The measurements were taken during 3 low back stabilization exercises. One-way analysis of variance with repeated measures was used to examine the difference, and a post hoc test was performed with least significant difference. A level of significance was set at p<.05. The significance of difference between men and women, and between the electromyographic recording sites was evaluated by an independent t-test. The EMG activity for the externus oblique and gluteus maximus muscles had significant differences among 3 exercises (p<.05). In males, the EMG activity for the external abdominal oblique muscle had significantly increased differences during exercises 1 and exercise 2 (p<.05). The gluteus maximus muscle had significantly increased differences during exercise 2 and exercise 3 (p<.05). In females, the multifidus muscle had significantly increased difference during exercise 3 (p<.05), the external abdominal oblique muscle had significantly increased difference during exercise 1 (p<.05). and the gluteus maximus muscle had significantly decreased difference during exercise 3 (p<.05). The results were that the external abdominal oblique muscle was apparently activated during the curl-up exercise in females and males, and the multifidus muscle was apparently activated during the bridging exercise in females and during the sling exercise in males and females.1)In comparison of the %MVC between males and females, exercise 2 and exercise 3 apparently activated of the multifidus and gluteus maximus muscles in both males and females (p<.05). The EMG activity of the gluteus maximus muscle of the males significantly increased during exercise 2 and exercise 3 (p<.05). The EMG activity the multifidus muscle of the females was significantly increased during exercise 2 and exercise 3 (p<.05). More research is needed to understand the nature of motor control problems in the deep muscles in patients with low back pain.

• The Journal of the Convergence on Culture Technology
• /
• v.6 no.4
• /
• pp.677-684
• /
• 2020

Our country is already in the aging corner and fall down is the elderly personal, social and economic problems are causing. therefore, executed this study for inquiring into an athletic effect for the balance ability increase that was a main variable of an fall down. The purpose of this study, to find the effect of balance training using visual feedback and somatosensory. Experimental group divided the three groups, objects measured balance ability of each experimental groups before experiment, the balance exercise group used visual feedback by Nintendo Wii(company - model), the balance exercise group used visual and TOGU, the balance exercise group used blind and TOGU. 4 experimental of each groups measured MFT and EMG value after training. having rest time, 4 experimental of each groups measured MFT and EMG value after training used balance pad. MFT - visual feedback with somatosensory training is most efficient but, indifferent both balance training with visual feedback and balance training with somatosensory. EMG - training with somatosensory is more efficient than training with visual feedback. Conclusion : in the process of improving equilibrium ability of patient who is lack of balance ability, somatosensory training is effective to correct different of left, right and frequency of left, right. visual feedback is the most effective way to improve dynamic balance sensory, so parallel of these two practice is thought to be the most effective.

• Physical Therapy Korea
• /
• v.14 no.2
• /
• pp.68-75
• /
• 2007

Reductions in strength and range of motion in older persons have been associated with decreased functional mobility and risk of falls. The purpose of this research was to investigate the effect of intensive dynamic balance exercise (DBE) during 8 weeks on onset time of medial gastrocnemius and tibialis anterior muscle contraction after perturbation in older women. Thirty subjects were randomly assigned into DBE group or control group. The DBE group participated in 50 minutes 3 days a week for 8 weeks. Surface electromyography (EMG) activity was recorded from the medial gastrocnemius and tibialis anterior muscles of left side. Outcome data were collected both groups at the pre-exercise and post-exercise. Independent t-test and paired t-test were used to determine the statistical difference. Results showed that the passive range of motion and functional reach test were significantly increased in the DBE group than the control group at the post-exercise (p<.05). The onset time of both muscles and discrepancy of onset time significantly reduced in the DBE group than the control group at the post-exercise (p<.05). The onset time of both muscles were significantly reduced in the post-exercise than the pre-exercise in the DBE group (p<.05). The discrepancy of onset time in the DBE group was significantly reduced in the post-exercise than the pre-exercise (p<.05). These findings suggest that intensive dynamic balance exercise for the eight weeks was effective in improving the postural control with older persons.

• Physical Therapy Rehabilitation Science
• /
• v.11 no.2
• /
• pp.127-135
• /
• 2022

Objective: The purpose of this study was to investigate the effects of combining Mulligan taping and flossing bands on lower limb muscle activity and static and dynamic balance. Design: A randomized controlled trial. Methods: Sixty-eight patients with chronic ankle instability were randomized into three groups that were treated with Mulligan taping (MT, n=22), flossing band (FB, n=23) and Mulligan taping combined with flossing band (MT+FB, n=23), and various parameters were compared before and after the intervention. The muscle activity of the lower extremities, including the tibialis anterior, peroneus longus and medial of gastrocnemius muscles was measured using BTS FREE EMG 1000, while the static and dynamic balance were measured using the Biorscuue balance measuring equipment. Results: There was a significant difference in muscle activity of the tibialis anterior muscle, before and after the intervention, in the MT group (p<0.01), FB (p<0.001) and MT+FB (p<0.001). There was also a significant difference in the muscle activity of the tibialis anterior muscle in the MT+FB group when compared with that in MT and FB groups (p<0.05). We also observed a significant difference in the dynamic balance all the groups (p<0.001). Conclusions: Therefore, combining Mulligan taping and flossing bands for patients with chronic ankle instability may improve dynamic balance and tibialis anterior muscle activity.