• The Journal of Korean Physical Therapy
• /
• v.22 no.5
• /
• pp.57-61
• /
• 2010

Purpose: The purpose of this study was to identify the effect of active foot arch support on the muscles of lower extremity electromyographic activity during squat exercise in persons with pronated foot. Methods: The study subjects were 16 persons with pronated foot. They have no history of surgery in lower extremity and trunk and limitation of range of motion or pain when performing squat exercise. Each subject was measured the navicular drop (ND) to determine the pronated foot. And then the subjects were asked to perform three repetitions of a $90^{\circ}$ knee flexion squat in both conditions which are 1) preferred squat and 2) squat with active foot arch support. Results: Paired t-test revealed that squat with active foot arch support produced significantly greater EMG activities in abductor hallucis (p=0.00), proneus longus (p=0.03) and gluteus medius (p=0.04) than preferred squat. But the EMG activities of tibialis anterior, vastus medialis oblique and vastus lateralis were not showed significantly different between the both squat conditions. Conclusion: The findings of this study suggest that active foot arch support during squat increase the activities of lower extremity muscles which are the abductor hallucis, proneus longus and gluteus medius. Also, the abductor hallucis which is one of the planter intrinsic muscle and peroneus longus play a role in support of the foot arch and active foot arch support induced the increase of the activity of gluteus medius. Therefore active foot arch support can change the lower extremity biomechanics as well as passive foot support such as foot orthotics and taping.

• Journal of the Korean Society of Physical Medicine
• /
• v.18 no.2
• /
• pp.83-92
• /
• 2023

PURPOSE: This study examined the effect of using a smartphone according to the direction of wearing a bag on muscle characteristics and balance ability in adults in their 20s with chronic ankle instability. METHODS: Twelve people with chronic ankle instability were examined for three weeks. The types of carrying a bag were classified into three conditions: to the right, to the left, and on both sides. The muscle characteristics and balance ability were measured and analyzed. The one-way ANOVA was used to obtain a difference between conditions. RESULTS: A significant difference in the muscle tone of medial gastrocnemius was observed between the dominant group and the non-dominant group. The muscle tone and stiffness of the peroneus longus decreased significantly after walking with a smartphone and carrying a bag. The maximum slope of the forward and reverse directions increased and decreased significantly, respectively, after walking with a smartphone and carrying a bag on both sides. CONCLUSION: In this study, muscle fatigue causes a decrease in muscle tone and stiffness with chronic ankle instability when carrying a heavy back while walking, and there were asymmetric changes in the balance ability. Therefore, adults with chronic ankle instability should carefully avoid carrying a heavy bag for extended times, irrespective of the style or type of the bag.

• PNF and Movement
• /
• v.17 no.2
• /
• pp.311-319
• /
• 2019

Purpose: This study was conducted to determine the structural change in knees caused by quadriceps angle and the muscle activity in lower limbs. Indirect intervention was provided by using taping for stability in the ankle joints, which affected patellofemoral pain. Methods: The subjects in this study were 20 patients with patellofemoral pain who visited ${\bigcirc}{\bigcirc}{\bigcirc} $ Hospital in Busan. The visual analogue scale measured the dynamic quadriceps angle and the degree of pain felt by the patients while walking down stairs, which was a known factor of patellofemoral pain. In addition, muscle activities in the rectus femoris, vastus lateralis, vastus medialis, tibialis anterior, peroneus longus, and biceps femoris, which affect the knees and ankles, were measured using surface electromyography. The muscle activities were converted into %RVC for this study. The data obtained in this study were analyzed with the Wilcoxon signed-rank test using the SPSS Ver. 25.0 statistical program. The significance level ${\alpha}$ was 0.05. Results: The study results showed that the pain and dynamic quadriceps angle were significantly reduced statistically when applying the calcaneus fixation taping (p<0.05). Muscle activity in the lower limbs was significantly decreased in the vastus medialis, vastus lateralis, and tibialis anterior (p<0.05). Conclusion: The summary of the study results verified that the calcaneus fixation taping reduced the pain and dynamic quadriceps angle by providing stability in the ankle joints. It also produced efficient movement due to the difference in lower-limb muscle activity.

• Journal of the Korean Society of Physical Medicine
• /
• v.17 no.4
• /
• pp.113-121
• /
• 2022

PURPOSE: This study is examined the effects of vestibular stimulation through eye movement on balance and muscle activity. METHODS: In 42 healthy adults, no eye exercise was applied to both feet and one foot. The speed of smooth pursuit eye movement (.2 Hz, .3 Hz, and .5 Hz) and saccadic eye movement (.5 Hz and 1.1 Hz) were randomized. The measurements were taken three times for 30 seconds while standing on two feet and measured three times for 10 seconds while standing on one foot. The muscle activity measurement equipment was used to measure the electromyogram signals of the tibialis anterior, peroneus longus, gastrocnemius medialis, vastus medialis, vastus lateralis, biceps femoris, abdominal internal oblique, and erector spinae muscle. RESULTS: As a result of this study, when applying smooth pursuit eye movement on one leg, the pressure center movement increased, the muscle activity of the lower extremity increased, in the saccadic eye movement, and the center of pressure decreased. CONCLUSION: Accordingly, the smooth pursuit of eye movement, the intervention of this study, affects balance. Through this, the balance can be improved by applying eye movement to the target who needs to improve the balance ability.

• Physical Therapy Korea
• /
• v.24 no.4
• /
• pp.46-53
• /
• 2017

Background: The MLA is supported by both the abductor hallucis (ABH) and the extrinsic muscles. Insufficient muscular support may lower the MLA when the body's weight is applied to the foot. The short foot exercise (SFE) is effective in increasing the height of the MLA for people with flat feet. Most of the research related to the SFE has simply evaluated the efficiency of the exercise using enhanced ABH electromyography (EMG) activation. Since the tibialis anterior (TA), peroneus longus (PER), and ABH are all involved in supporting the MLA, a new experiment design examining the EMG of the selected muscles during SFE should be applied to clarify its effect. Objects: Therefore, this study aimed to clarify the effect of the SFE in different ankle position on the MLA angle and the activation of both the intrinsic and extrinsic muscles and to determine the optimal position. Methods: 20 healthy subjects and 12 subjects with flat feet were recruited from Yonsei University. The surface EMG and camera were used to collect muscle activation amplitude of TA, PER, and ABH and to capture the image of MLA angle during SFE. The subjects performed the SFE while sitting in three different ankle positions-neutral (N), dorsiflexion (DF) at 30 degrees, and plantar flexion (PF) at 30 degrees. Results: ABH EMG amplitudes were significantly greater in N and DF than in PF (p<.05). Muscle activation ratio of TA to ABH was the lowest in PF (p<.05). MLA angle in both groups significantly decreased in PF (p<.01). The TA and ABH was activated at the highest level in DF. However, in PF, subjects significantly activated the ABH and PER with relatively low activation of TA. Conclusion: Therefore, researchers need to discuss which SFE condition most effectively use the arch support muscle for flat foot.

• The Journal of Korean Physical Therapy
• /
• v.34 no.5
• /
• pp.218-223
• /
• 2022

Purpose: This study sought to identify the effects of an insole applied for the flexible flat-foot condition on dynamic balance and ankle muscle activities during the Y-balance test (YBT). Methods: Thirteen flexible flat-footed adults and an equal number of normal-footed adults were enrolled. The dynamic balance of the subjects was measured using the YBT, which is a reach test. While they were reaching forward with their foot, the percentage maximum voluntary isometric contraction (MVIC) of the tibialis anterior, peroneus longus and medial and lateral gastrocnemius were measured and analyzed. The flat-footed group then applied the ready-made insoles and underwent the YBT again. A comparison of the distance and muscle activity was conducted using YBT, not only between the flat-footed and control group, but also between the flat-footed group before and after the application of the insole. Results: Between the groups, the anterior reach distance in the flat-footed group was significantly lower, but there were no significant differences observed in the posteromedial and posterolateral directions. With the insole, the reach distance of the flat-footed group was significantly increased in the anterior and posterolateral direction compared to the control group. With the insole, the lateral gastrocnemius activity significantly decreased compared to trials without the insole in the flat-footed group, but there were no significant differences in the other muscles. Conclusion: The insole for flat-footed subjects can maintain the medial arch of the foot, and it may help enhance functional and mechanical dynamic balance in people with flat feet.

• Physical Therapy Korea
• /
• v.31 no.1
• /
• pp.63-71
• /
• 2024

Background: Individuals with pes planus tend to overuse the extrinsic foot muscles, such as the tibialis anterior (TA) and peroneus longus (PL), to compensate for the weakened intrinsic foot muscles, such as the abductor hallucis (AbdH). Furthermore, differences in weight-bearing can affect the activity of muscles in both the intrinsic and extrinsic foot muscles. To date, no study has compared the effects of the short foot exercise (SFE) and toe spread-out exercise (TSO) on intrinsic and extrinsic foot muscle activity and the corresponding ratios in different weight-bearing positions. Objects: To compare the effects of the SFE and TSO on AbdH, TA, and PL activity and the AbdH/TA and AbdH/PL activity ratios in the sitting and standing positions in individuals with pes planus. Methods: Twenty participants with pes planus were recruited. Surface electromyography was used to assess the amplitudes of AbdH, TA, and PL activity. Participants performed both exercises while adopting both the sitting and standing positions. Results: No significant interaction between exercise and position was found regarding the activity of any muscle or ratio of the activity, except for PL activity. We observed a significant increase in AbdH activity during the TSO compared to the SFE, and no significant difference in TA and PL activity between the two exercises. AbdH, TA, and PL activity were significantly higher in the standing position than in the sitting position. Furthermore, the AbdH/PL activity ratio significantly increased in the sitting position, although there was a significant increase in AbdH activity in the standing position. Conclusion: In individuals with pes planus, we recommend performing the TSO in the sitting position, which may increase the activity of the AbdH while concurrently decreasing the activity of the TA and PL, thus strengthening the AbdH.

• PNF and Movement
• /
• v.17 no.2
• /
• pp.207-214
• /
• 2019

Purpose: Although multi-directional reaching exercises are commonly used clinically, the effects of specific movement directions on the muscle systems of the lower extremities have not been explored. We therefore investigated lower extremity muscle activity during reaching exercises with different sagittal and horizontal plane movements. Methods: The surface electromyography responses of the bilateral rectus femoris, tibialis anterior, peroneus longus, and gastrocnemius muscles were measured during reaching exercises in three directions in the horizontal plane (neutral, $45^{\circ}$ horizontal shoulder adduction, and $45^{\circ}$ abduction) and three directions in the sagittal plane (neutral, $120^{\circ}$ flexion, and $60^{\circ}$ flexion). A total of 20 healthy, physically active participants completed six sets of reaching exercises. Two-way repeated ANOVA was performed: body side (ipsilateral and contralateral) was set as the intra-subject factor and direction of reach as the inter-subject factor. Results: Reaching at $45^{\circ}$ horizontal shoulder adduction significantly increased the activity of the contralateral rectus femoris and gastrocnemius muscles, while $45^{\circ}$ horizontal shoulder abduction activated the ipsilateral rectus femoris and gastrocnemius muscles. The rectus femoris activity was significantly higher with reaching at a $120^{\circ}$ shoulder flexion compared to the other conditions. The gastrocnemius activity decreased significantly as the shoulder elevation angle increased from $60^{\circ}$ to $120^{\circ}$. Conclusion: Our results suggest that multi-directional reaching stimulates the lower extremity muscles depending on the movement direction. The muscles acting on two different joints responded to the changes in reaching direction, whereas the muscles acting on one joint were not activated with changes in reaching direction.

• Korean Journal of Applied Biomechanics
• /
• v.25 no.1
• /
• pp.103-111
• /
• 2015

Objective : The purpose of this study was to evaluate the effect for running shoes with resilience of midsole on biomechanical properties. Methods : 10 healthy males who had no history of injury in the lower extremity with an average age of 26.5 year(SD=1.84), height of 172.22 cm(SD=4.44) and weight of 67.51 kg(SD=6.17) participated in this study. All subjects ran on the treadmill wearing three different running shoes. Foot pressure data was collected using Pedar-X system(Novel Gmbh, Germany) operating at 100 Hz. Surface EMG signals for biceps femoris, rectus femoris, vastus lateralis, medial lateralis, tibialis anterior, medial gastrocnemius, soleus and peroneus longus were acquired at 1000 Hz using Bignoli 8 System(Delsys Inc., USA). To normalize the difference of the magnitude of muscle contractions, it was expressed as a percentage relative to the maximum voluntary contraction (MVC). The impact resilience of the midsole data was collected using Fastcam SA5 system(Photron Inc., USA). Collected data was analyzed using One-way ANOVA in order to investigate the effects of each running shoes. Results : TPU midsole was significantly wider in contact area than EVA, TPE midsole in midfoot and higher in EMG activity than EVA midsole at biceps femoris. TPE midsole was significantly wider in contact area than EVA midsole in rearfoot and higher in peak pressure than EVA midsole in forefoot. EVA midsole was significantly higher in EMG activity than TPU midsole at tibia anterior. In medial resilience of midsoles, TPE midsole was significantly higher than EVA, TPU midsole. Conclusion : TPU midsole can reduce the load on the midfoot effectively and activate tibialis anterior, biceps femoris to give help to running.

• Journal of Industrial Convergence
• /
• v.18 no.1
• /
• pp.59-64
• /
• 2020

The effect of kinesio taping in patients with common peroneal nerve paralysis (PNP) have not been investigated. This purpose of this study was to evaluate the effects of kinesio taping on patients with common PNP. Ten subjects who had common PNP were included in this study. Kinesio taping was applied to the ankle joint (direction of dorsiflexion and eversion). The measurements were by manual muscle test (MMT; tibialis anterior, peroneus longus), active ROM (ankle dorsiflexion, eversion), pain (visual analogue scale (VAS), pressure pain threshold (PPT)), and balance (one leg standing). Subjects were assessed at baseline and 8 weeks of intervention. In the results, all subjects showed improvements in MMT, active ROM, Pain and balance at the 8-week. These findings are considered to be effective in applying kinesio taping on ankle joint in common PNP patients.