• Journal of Mechanical Science and Technology
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• 제20권8호
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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.

• The Journal of Korean Physical Therapy
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• 제34권4호
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• pp.181-186
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• 2022

Purpose: This study was to applied to stretching plantar flexor and invertor at the same time to observe the effect of balance and walking ability. Methods: Subjects were instructed patients with ankle limited of motion, 6 months after stroke. We classified 20 subjects into two groups (experimental group: stretching plantar flexor and invertor at the same time, control group: only stretching plantar flexor). each group included 10 subjects and applied ankle stretcher for 20 minutes, 5 times/week during 4 weeks (total 20 times). Results: Both experimental group and control group showed significant increases in static balance, however, the significantly increases in step length and gait speed was observed only in the experimental group. There was no significant increases in step length and gait speed in the control group. Conclusion: Simultaneous stretching of ankle invertor and plantar flexion is effective in improving balance and walking ability in chronic stroke patients.

• 대한족부족관절학회지
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• 제21권2호
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• pp.55-60
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• 2017

Purpose: Stiffness in the first metatarsophalangeal joint after surgery for hallux valgus has been reported. The goal of this study was to test the efficacy of releasing plantar aponeurosis for improving the range of extension in the first metatarsophalangeal joint that was limited after hallux valgus surgery. Materials and Methods: Thirteen patients (1 man, 12 women [17 feet]; median age, 54.4 years; range, 44~69 years) with limited first metatarsophalangeal joint extension after hallux valgus surgery, who underwent an additional procedure of plantar aponeurosis release between March 2015 and August 2015, were included. Subsequently, the passive range of extension in the first metatarsophalangeal joint was evaluated via knee extension and flexion positions. Hallux valgus angle, inter-metatarsal angle, distal metatarsal articular angle, and talo-first metatarsal angle were measured on weightbearing dorsoplantar and lateral radiographs of the foot preoperatively. Results: The mean range of extension for the first metatarsophalangeal joint improved significantly, from $2.5^{\circ}$ to $40.9^{\circ}$ in the knee extension position (p<0.00). The mean extension range for the first metatarsophalangeal joint also improved, from $18.2^{\circ}$ to $43.2^{\circ}$ in the knee flexion position (p<0.00). In all patients, congruence of the first metatarsophalangeal joint was recovered. Conclusion: Plantar aponeurosis release is an effective additional procedure for improving the extension range of the first metatarsophalangeal joint after hallux valgus surgery.

• PNF and Movement
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• 제17권3호
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• pp.463-469
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• 2019

Purpose: This study investigated the effect of plantar-flexor muscle fatigue on the force sense and joint reposition sense of ankle joints in the healthy adults. Methods: Fifteen healthy subjects (male: 9, female: 6) participated in this study. A digital dynamometer was used to measure the force sense error while a wireless motion capture device was used to measure the joint reposition sense error. To induce plantar-flexor muscle fatigue for a dominant lower extremity, the subjects were asked to perform plantar flexion until exhaustion while barefoot. The differences in force sense error and joint reposition sense error for the ankle joint were measured immediately. The Wilcoxon test was used to compare these values before and after inducing plantar-flexor muscle fatigue. Results: The force sense error and joint reposition sense error of ankle joints after inducing plantar-flexor muscle fatigue increased significantly compared to the values before inducing muscle fatigue. Conclusion: This study suggests that plantar-flexor muscle fatigue could degrade the force sense and joint reposition sense in ankle joints. In addition, it could deteriorate ankle proprioception.

• 한국운동역학회지
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• 제26권2호
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• pp.153-159
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• 2016

Objective: The purpose of this study was to investigate the effects of joint mobilization on foot pressure, ankle moment, and vertical ground reaction force in subjects with ankle instability. Method: Twenty male subjects (age, $25.38{\pm}3.62yr$; height, $170.92{\pm}5.41cm$; weight, $60.74{\pm}9.63kg$; body mass index (BMI), $19.20{\pm}1.67kg/m^2$) participated and underwent ankle joint mobilization. Weight-bearing distribution, ankle dorsi/plantar flexion moment, and vertical ground reaction force were measured using a GPS 400 and a VICON Motion System (Oxford, UK), and subsequently analyzed. SPSS 20.0 for Windows was used for data processing and paired t-tests were used to compare pre- and post-mobilization measurements. The significance level was set at ${\alpha}$ = .05. Results: The results indicated changes in weight-bearing, ankle dorsi/plantar flexion moment, and vertical ground reaction force. The findings showed changes in weight-bearing distribution on the left (pre $29.51{\pm}6.31kg$, post $29.57{\pm}5.02kg$) and right foot (pre $32.40{\pm}6.30kg$, post $31.18{\pm}5.47kg$). There were significant differences in dorsi/plantar flexion moment (p < .01), and there were significant increases in vertical ground reaction forces at initial stance (Fz1) and terminal stance (Fz2, p < .05). Additionally, there was a significant reduction in vertical ground reaction force at midstance (Fz2, p < .001). Conclusion: Joint mobilization appears to alter weight-bearing distribution in subjects with ankle instability, with resultant improvements in stability.

• Physical Therapy Rehabilitation Science
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• 제6권4호
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• pp.182-188
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• 2017

Objective: The purpose of this study was to compare ankle function between adults with and without Down syndrome (DS). Design: Cross-sectional study. Methods: Ten adults with DS and 18 without participated in this study and underwent manual muscle test (MMT), range of motion (ROM) assessment, star excursion balance test (SEBT), and functional movement screen (FMS). The tests were demonstrated to increase their accuracy and the actual measurements were assessed after one or two demonstrations. To minimize the standby time and fatigue, the travelled distance and measuring order were adjusted. To remove the influence of shoes on the measurements, the shoes were taken off and only socks were worn. Results: Dorsal and plantar flexion MMTs of both ankles were significantly weaker and plantar flexion ROM of both ankles were significantly lower in adults with DS compared with those without (p<0.05). However, dorsal flexion ROM of both ankles were not significantly different between them. There were significant differences in distances measured in all the directions (anterior, anterolateral, lateral, posterolateral, posterior, posteromedial, medial, and anteromedial directions) of SEBT (p<0.05). Significant differences were also demonstrated in the scores of hurdle step, inline lunge, shoulder mobility, and rotary stability among the seven items of FMS (p<0.05). Conclusions: To enhance the dynamic stability of adults with DS, it is necessary to improve ankle stability by strengthening the ankle dorsal and plantar flexors.

• 한국운동역학회지
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• 제23권4호
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• pp.335-345
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• 2013

The purpose of this study was to investigate the effects of foot type and ankle joint fatigue levels on the trajectories of center of pressure and center of mass during a single-leg stance. The study subjects included 24 healthy women (normal foot group, n=10; pronated foot group, n=14). Ankle joint muscle fatigue was induced by using an isokinetic dynamometer, where the fatigue levels were measured on plantar flexion and dorsiflexion at angular velocities of $30^{\circ}/s$ at 50% and 30% of the peak torque of ankle plantar flexion. Following assessments in the anteroposterior direction according to the level of fatigue, the pronated foot group showed decreased single-leg stance ability at 50% and 30% of the fatigue level. Moreover, the normal foot group showed better single-leg stance ability than the pronated foot group at 30% of the fatigue level. Following assessments in the mediolateral direction, we noted that the single-leg stance ability did not differ significantly according to the levels of fatigue or foot type. In conclusion, ankle plantar flexion at 50% and 30% of the peak torque reduced the ability of the pronated foot group to achieve a single leg stance in the anteroposterior direction. Moreover, the normal foot group showed better single-leg stance ability than the pronated foot group.

• 대한물리의학회지
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• 제10권3호
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• pp.87-93
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• 2015

PURPOSE: The purpose of this study was to investigate the effects of the 8.5seconds cut-off of the 8-foot up-and-go test as a predictor of falling and a good discriminator of fallers and non-fallers in women in their 60s to 80s. METHODS: The final subjects of this study were 98 elderly women from six senior centers of B metropolitan city. The 8-foot up-and-go test evaluated agility and dynamic balance. The chair-stand test measured the muscle strength for of the lower body. Ankle dorsiflexion and plantar flexion were measured to assess the ankle mobility of the subjects in this study. RESULTS: The below 8.5seconds group showed significantly low values in age and high values in chair-stand (times/30 s), plantar flexion ($^{\circ}$), and K-MMSE (score) compared to the over 8.5seconds group. This group was significantly faster compared to the over 8.5seconds group. In the below 8.5seconds group, only plantar flexion ($^{\circ}$) of all the items showed significantly higher values among those in their 60s compared to those in their 70s and 80s. CONCLUSION: The 8.5seconds cut-off on the 8-foot up-and-go test as a good discriminator and predictor of falling showed differences among fall risk factors (age, lower extremity strength, cognition, and ankle mobility) in women in their 60s to 80s without having regular exercise and a fall experience over the past ones year.

• Physical Therapy Rehabilitation Science
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• 제12권1호
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• pp.26-32
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• 2023

Objective: This study attempted to compare the effects of bridge exercise using a sling according to the angle of the ankle to confirm the effective lower extremity muscle activation posture of patients with patellofemoral pain syndrome(PFPS). Design: Cross-sectional study Methods: Seventeen patients with PFPS were recruited and the muscle activities of the vastus medialis, vastus lateralis, rectus femoris, and gluteus maximus were measured according to the ankle position (dorsiflexion, neutral, plantar flexion). After measuring the maximum number of isometric contractions of vastus medialis, vastus lateralis, rectus femoris, and gluteus maximus, bridging exercise using a sling according to each ankle posture was applied to measure lower extremity muscle activity. The evaluation was performed 3 times for 10 seconds. The three ankle postures were randomly performed and the average values were compared. Results: As a result of this study, the vastus medialis muscle showed high muscle activity in the order of dorsiflexion, plantar flexion, and neutral position bridge exercise (p<0.05). And the vastus lateralis showed high muscle activity in the order of dorsiflexion, neutral, and plantar flexion (p<0.05). However, rectus femoris and gluteus maximus did not show significant muscle activity according to the ankle posture, but muscle activity was highest in the dorsiflexion posture. Conclusions: As a result of this study, muscle activity was high in the order of vastus medialis and vastus lateralis during ankle dorsiflexion. This is thought to be a major factor that can be applied in various ways in clinical practice according to the ankle angle when treating PFPS patients.

• 한국운동역학회지
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• 제18권1호
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• pp.1-10
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• 2008

본 연구는 축구 인스텝 킥에서 지지 다리의 후족각과 차는 다리의 해부학적 회전 운동의 자료들을 분석해서 다음과 같은 결론을 얻었다. 발목 관절에서의 외반각은 지지발의 접지 이전에 최대 피크에 도달했으며, 저측 굴곡은 그룹 간 최대 피크의 타이밍에서 약간의 차이가 나타났다. 지지발의 접지 시 후족의 굴곡각은 그룹 간 통계적으로 유의한 차이가 났으며, 지지발의 접지 시 하퇴의 운동은 그룹 간 유의한 차이가 없었다. 접지 이전에 이미 하퇴를 후방으로 많이 기울였으며, 임팩트 순간 하퇴의 좌우 기울기는 22도였다. 차는 다리 고관절의 굴곡/신전은 지지발의 접지 시 최대 피크에 이르렀으며, 이 순간 고관절의 최대 신전각은 30도 이상으로 나타났다. 차는 다리 무릎 관절의 굴곡각은 접지와 임팩트의 사이에 최대로 굽혔으며, 족관절의 최대 저측 굴곡각과 최대 외번각은 그룹 간 유의한 차이는 나지 않은 반면, 최대 외측 회전각은 유의한 차이가 났다.