• PNF and Movement
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• v.21 no.3
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• pp.319-326
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• 2023

Purpose: The purpose of this study was to investigate the effects of modified ankle movement patterns on participants' active dorsiflexion range of motion and leg muscle activity. Methods: This study recruited twenty-five participants, all of whom were healthy individuals with no abnormalities in the ankle or knee joints. The research methodology involved measuring the active dorsiflexion range of motion and muscle activity in each person's legs based on the presence or absence of toe extension while the subjects were in a comfortable, supine position. A statistical analysis was conducted using SPSS 25.0, and a paired samples t-test was employed. The significance level was set at 0.05. Results: When the participants demonstrated the modified ankle movement pattern with a controlled toe grip, there was an increase in their active dorsiflexion angle. However, during the proprioceptive neuromuscular facilitation technique without a controlled toe grip, a higher level of activity was observed in the leg muscles. Conclusion: The results of this study could be used as foundational data for establishing a rehabilitation exercise program designed to enhance range of motion and muscle activation in the ankle joint.

• Physical Therapy Rehabilitation Science
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• v.9 no.2
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• pp.113-119
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• 2020

Objective: The vibration device is one of the most commonly used warm-up devices not only for healthy athletes but also for healthy individuals. Therefore, this study aimed to investigate the immediate effects of local vibration on ankle plantar flexor muscle activation and peak torque in healthy adults. Design: One-group pretest-posttest design. Methods: This was a single-group study comprising a total of 36 (16 males and 20 females) participants. The average age of the 36 participants was 22.3 years. All the participants' concentric and eccentric peak torques of the gastrocnemius lateralis muscle were measured using an isokinetic device. Simultaneously, the participants' muscle activity was measured by surface electromyography. After the pre-experimental data were collected, the participants comfortably sat on the prepared chair with their hips and knees flexed to 90°. While in sitting position, local vibration was applied for 10 minutes using a 1:1 ratio intermittent pulsing mode device based on a previous study. Then, the post-experimental data were collected immediately after the local vibration by performing a similar process performed during the pre-experimental data collection. Results: The results showed a significant difference in muscle activity and eccentric peak torque (p<0.05). On the contrary, concentric peak torque values showed an insignificant difference with pre- and post-value. Conclusions: The results of this study demonstrated that local vibration can be possibly considered as one of the effective ways to increase ankle plantar flexor muscle activity and muscle performance, specifically the eccentric peak torque, in healthy adults.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.3
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• pp.65-72
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• 2023

PURPOSE: This study assessed the influence of bilateral coordination exercises on unstable support surfaces on leg muscle activation and balance in stroke patients. METHODS: Two groups were recruited for comparison: an experimental group of 10 individuals who performed bilateral coordination exercises on unstable surfaces and a control group of 10 individuals who performed the same exercises on stable surfaces. All participants were assigned randomly. Pre-tests were conducted to measure the leg muscle activation and balance levels of the participants prior to the experiment. The intervention was comprised of three 30-minute weekly sessions for four weeks, followed by a post-test after the four-week period. RESULTS: Significant differences were identified within the experimental group in relation to all muscles (p < .01) and balance (p < .05). Within the control group, significant differences were identified in relation to the rectus femoris muscle, biceps femoris muscle, and balance (p < .05). Significant differences between the two groups were only observed in relation to the tibialis anterior and soleus muscles (p < .05). CONCLUSION: Only the tibialis anterior and soleus muscles showed significant differences between the two groups. This effectiveness may be attributed to using an ankle strategy to maintain body balance during exercise on unstable surfaces.

• Physical Therapy Korea
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• v.21 no.2
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• pp.57-66
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• 2014

The objective of this study was to determine the duration of maintained calf muscle flexibility gained in young adults with calf muscle tightness, as measured by increases in ankle active and passive dorsiflexion range of motion (DFROM) after three stretching interventions. Twenty subjects (5 men and 15 women) with calf muscle tightness received the following three stretching interventions in one leg (assigned at random): static stretching (SS), eccentric training on stable surface (ETS), and eccentric training on unstable surfaces (ETU). The subjects received all three interventions to the same leg, applied in a random order. Each intervention had a break of at least 24 h in-between, in order to minimize any carryover effect. Each intervention used two types of stretching: with the calf muscle stretched and both knees straight, and with the knee slightly bent in order to maximize the activation of the soleus muscle. All three interventions were performed for 200 seconds. We measured the duration of maintained calf muscle flexibility through active and passive ankle DFROM before intervention, immediately after intervention (time 0), and then 3, 6, 9, 15, and 30 min after intervention. We found a difference in the duration of maintained calf muscle flexibility between the three interventions. In the ETS and ETU interventions, a significant improvement in calf muscle flexibility, both ankle active and passive dorsiflexion ranges of motion (ADFROM and PDFROM), was maintained for 30 min. In the SS intervention, however, ADFROM before 9 min and PDFROM before 6 min were statistically different from the baseline. Our results suggest that ETS and ETU may be more effective than SS for maintaining calf muscle flexibility in young adults.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.1
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• pp.1-8
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• 2023

PURPOSE: This study analyzed how proprioceptive neuromuscular facilitation (PNF) combined with auricular acupuncture affected the activation of the leg muscles of stroke patients and measured the effects of this combination to provide clinical data. METHODS: The subjects were divided randomly into experimental group I, which received PNF combined with auricular acupuncture, and experimental group II, which received PNF alone. Each group had ten members. A 30-minute intervention was performed four days a week for six weeks. Before the six weeks of intervention, pre-tests were conducted to measure muscle activation in the legs. After six weeks, post-tests were also conducted to measure muscle activation in the legs. RESULTS: Experimental group I showed a statistically significant difference in muscle rectus femoris, muscle biceps femoris, muscle tibialis anterior, and muscle soleus. Experimental group II also showed a statistically significant difference in the muscle rectus femoris, muscle biceps femoris, muscle tibialis anterior, and muscle soleus (p < .05). In a between-group comparison of the changes, a statistically significant difference was observed between the two groups in terms of muscle rectus femoris, muscle biceps femoris, muscle tibialis anterior, and muscle soleus (p < .05). CONCLUSION: Intervention in experimental group I increased the activation of the leg muscles more effectively because auricular acupuncture was applied to various spots on the ear corresponding to the spleen, liver, kidney, pelvis, knee, ankle, and toe. Auricular acupuncture is expected to be used more widely in the future because it is a safe way of stimulating muscle activation.

• The Journal of Korean Physical Therapy
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• v.23 no.1
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• pp.1-5
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• 2011

Purpose: The purpose of this study was to investigate changes in muscle activation associated with foot position during a sit-to-stand exercise among normally healthy elderly subjects. Methods: Eight subjects (male=3; female=5; mean age=$70.13{\pm}{\pm}2.53$years) were recruited.The activation of six muscles (neck extensor; lumbar extensor; hamstring; rectus femoris; gastrocnemius; tibialis anterior) was measured by surface EMG (TeleMyo 2400T G2, Noraxon Inc., USA) during a sit-to-stand protocol under three different foot positions (ankle dorsiflexion of 0, 15, or 30 degrees). Results: Muscle activation of the neck extensor and hamstring was decreased according to the change in foot position (p<0.05), but activation of the rectus femoris was increased (p<0.05). Muscle activation of the neck extensor was significantly different between 0 and 15 degrees (p<0.05). Muscle activation of the hamstring was significantly different between 0 and 15 degrees and between 0 and 30 degrees (p<0.05). Muscle activation of the rectus femoris was significantly different between 0 and 30 degrees and between 15 and 30 degrees (p<0.05). However, activation of lumbar extensor, gastrocnemius and tibialis anterior muscles did not significantly differ between foot positions. Conclusion: These findings suggest that muscle activation during a sit-to-stand movement differs depending on foot position. We believe that these differences should be considered when educating the elderly regarding proper body movements.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.4
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• pp.113-122
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• 2017

PURPOSE: The purpose of this study was to investigate the comparison of muscle activity and mechanical loading according to the angle of ankle joint during a sit-to-stand (STS) task. METHODS: Thirty-four young participants performed the STS in a randomized trial with the ankle joint at a neutral, 15 degrees dorsiflexion and 15 degrees plantarflexion angle in a fixed sitting posture with the knee in 105 degrees flexion. Muscle activity of the tibialis anterior (TA), rectus femoris (RF), biceps femoris (BF), and gastrocnemius medialis (GCM) was measured, and the parameters calculated in relation to mechanical loading were the STS-time, maximum peak, minimum peak, and total sum of mechanical loading. RESULTS: In the dorsiflexion position, the muscle activity of the TA and GCM showed a significant increase (p<.05), and the STS time, maximum peak and total sum of mechanical loading showed a significant difference compared to that in the neutral position (p<.05). In the plantarflexion position, the muscle activity of the RF and GCM showed a significant increase (p<.05), while that of the TA showed a significant decrease (p<.05) compared to that in the neutral position. And the minimum peak was significantly increased than the neutral position (p<.05), and the maximum peak and total sum of mechanical loading were showed significant difference compared with dorsiflexion position (p<.05). CONCLUSION: These results show that there is a difference in muscle activity and mechanical loading when performing the STS movement according to the change in the ankle joint angle.

• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.399-415
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• 2014

The aim of this study was to investigate the effect of resistance training with and without whole-body vibration(WBV) on the biomechanical properties of the plantarflexor in the elderly women (>60 yrs., n=35). Thirty-five volunteers were randomly assigned to a resistance training with WBV group (RVT, n=14), a resistance training without WBV (RT, n=11), and a non-training control group (CON, n=10). The RVT and the RT groups participated in the training sessions three times a week for 8 weeks, followed by a 4-week detraining period. The CON group was instructed to refrain from any type of resistance training. To assess strength and activation of the plantarflexor muscles, maximum isometric ankle plantarflexion torque and muscle activation of the triceps surae muscles were measured using dynamometry, twitch interpolation technique and electromyography at four different ankle joint angles. Also, the lower extremity function was assessed by vertical jumping. The measurements were performed prior to, 2 and 8 weeks after the training and after a 4-week detraining period. Following the 8-week training sessions, an increase in the isometric plantarflexion strength was found to be greater for the RVT compared with the RT group (p<.05). Muscle inhibition was significantly decreased after training than before training only for the RVT (p<.05). Following the detraining period, a decrease in isometric plantarflexors strength and a increases in muscle inhibition were significantly less in the RVT compared with the RT group. In conclusion, the exercise with WBV is a feasible training modality for the elderly and seems to have a boosting effect when used with conventional resistance training.

• Journal of Mechanical Science and Technology
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• v.20 no.8
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• pp.1183-1194
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• 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
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• v.22 no.1
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• pp.1-8
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• 2015

The purpose of this study was to compare the change in electromyography (EMG) activity in the gluteus maximus (G-max) and the gluteus medius (G-med) in subjects with and without chronic ankle instability (CAI) during three functional postures. Twenty four females were recruited for this study. Subjects were assigned into two groups: with CAI ($n_1=12$) and without CAI ($n_2=12$). The assessment postures were rotational squat, one leg stand above a gradient and crossed leg-sway. Electromyographic activities of the G-max and the G-med were recorded using surface EMG and was normalized using the maximal voluntary isometric contraction elicited using a manual muscle testing. Independent t-test was used to determine the statistical differences between two groups during the three functional postures. The comparisons of the three posture between two groups were performed using a one-way repeated analysis of variance. A Bonferroni adjustment used for post hoc analysis. The activation of EMG on G-max performing the one leg stand above a gradient and crossed leg-sway in subjects with CAI is significantly higher than normal group (p<.05). The activation of EMG on the G-max during the rotational squat was significantly increased, compared to those of the one leg stand above a gradient and crossed leg-sway (p<.05). The activation of EMG on G-med performing three exercise at CAI is significantly higher than normal group (p<.05). The activation of EMG on the G-med during the crossed leg-sway was significantly increased, compared to the rotational squat (p<.05). This study provides valuable information for clinician who research CAI.