Eversion Torque Research Articles

발 운동이 발아치 높이, 발배뼈 하강, 발목관절 토크에 미치는 영향

Purpose: The purpose of this study is to investigate the effects of six weeks of foot exercises, including calf raises and arch lifts, on foot arch height, navicular drop, and maximum ankle joint torque.BR Method: The 20 subjects were randomly divided into 10 experimental groups and 10 control groups. All the subjects were measured for foot arch height in the conditions of sitting, standing with two legs and one leg, navicular drop, and ankle joint torque. Correlation coefficients were obtained among foot arch height, navicular drop, and ankle joint torque, and a paired t-test was performed on foot arch height, navicular drop, and ankle joint torque before and after six weeks of foot BR Results: Six weeks of foot exercises maintained the relationship between the arch height and ankle joint plantar flexion-dorsiflexion maximum torque under the three loading conditions of sitting, standing with two legs, and one leg, while minimizing the relationship with the maximum eversion torque. It was also found that the relationship between navicular drop and ankle joint maximum torque was minimized. Also, six weeks of foot exercises eliminated a significant difference in the maximum torque of the ankle joint, increased the height of the arch of the foot, and showed a tendency to increase foot stiffness.BR Conclusion: Six weeks of foot exercises, including calf raises and arch lifts, affects foot arch height, navicular drop, and maximum ankle joint torque.

Does Ankle Inversion Or Eversion Torque Correlate With Reaction Time In Collegiate Women Soccer Players?

Does Ankle Inversion Or Eversion Torque Correlate With Reaction Time In Collegiate Women Soccer Players?

Upper body and ankle strategies compensate for reduced lateral stability at very slow walking speeds.

At the typical walking speeds of healthy humans, step placement seems to be the primary strategy to maintain gait stability, with ankle torques and upper body momentum providing additional compensation. The average walking speeds of populations with an increased risk of falling, however, are much slower and may require differing control strategies. The purpose of this study was to analyse mediolateral gait stability and the contributions of the different control strategies at very slow walking speeds. We analysed an open dataset including kinematics and kinetics from eight healthy subjects walking at speeds from 0.1 to 0.6 m s-1 as well as a self-selected speed. As gait speed slowed, we found that the margin of stability (MoS) decreased linearly. Increased lateral excursions of the extrapolated centre of mass, caused by increased lateral excursions of the trunk, were not compensated for by an equivalent increase in the lateral centre of pressure, leading to decreased MoS. Additionally, both the ankle eversion torque and hip abduction torque at the minimum MoS event increased at the same rate as gait speed slowed. These results suggest that the contributions of both the ankle and the upper body to stability are more crucial than stepping at slow speeds, which have important implications for populations with slow gait and limited motor function.

Kinetic effect of the taping on the ankle during a change of direction in basketball players

The purpose of this study was to compare the kinetic effect, with (WT) and without (WoT) the use of ankle taping, during a change of direction in basketball players. Twenty-two players were evaluated (11 men, 11 women; age = 21.50 ± 1.74 years, mass = 72.80 ± 13.14 kg, height = 1.71 ± 0.11 m). The functional task of “change of direction in 60°” was registered with a 3D motion analysis system and a force plate. The torques of eversion, plantarflexion, and ankle joint reaction force were evaluated during the braking phase, using an inverse dynamics method. To compare between conditions a t-student or Wilcoxon tests were used. The results revealed that the use of ankle taping yield a decrease in the anterior joint reaction force (WoT = 4.21 ± 1.36 N/kg vs WT = 2.92 ± 1.07 N/kg, p < .0001) and the eversion torque (WoT = 0.56 ± 0.24 Nm/kg vs WT = 0.51 ± 0.20 Nm/kg, p = .02) during a change of direction in 60o. In conclusion, according to the sample of assessed basketball players, the use of this bandage could contribute to the functional stability of the ankle, decreasing the torque of fibularis muscles and the shear anterior-posterior between the shank-foot segments.

An Ankle–Foot Prosthesis Emulator With Control of Plantarflexion and Inversion–Eversion Torque

Ankle inversion–eversion compliance is an important feature of conventional prosthetic feet, and control of inversion, or roll, in active prostheses could improve balance for people with amputation. We designed a tethered ankle–foot prosthesis with two independently actuated toes that are coordinated to provide plantar-flexion and inversion–eversion torques. A Bowden cable tether provides series elasticity. The prosthesis is simple and lightweight, with a mass of 0.72 kg. Strain gauges on the toes measure torque with less than 1% root mean squared (RMS) error. Benchtop tests demonstrated a step response rise time of less than 33 ms, peak torques of 250 N $\cdot$ m in plantarflexion and $\pm$ 30 N $\cdot$ m in inversion–eversion, and peak power above 3 kW. The phase-limited closed-loop torque bandwidth is 20 Hz with a chirp from 10 to 90 N $\cdot$ m in plantarflexion, and 24 Hz with a chirp from $-$ 20 to 20 N $\cdot$ m in inversion. The system has low sensitivity to toe position disturbances at frequencies of up to 18 Hz. Walking trials with an amputee subject demonstrated RMS torque tracking errors of less than 5.1 N $\cdot$ m in plantarflexion and less than 1.5 N $\cdot$ m in inversion–eversion. These properties make the platform suitable for testing inversion-related prosthesis features and controllers in experiments with humans.

Effects of Peroneal Muscles Fatigue on Dynamic Stability Following Lateral Hop Landing: Time to Stabilization Versus Dynamic Postural Stability Index

Dynamic stability is a necessary requirement in many sports competitions. Muscle fatigue, which can impair stability, may be occurred in many sports competitions in which lateral movements and landing repeated frequently. To assess the effects of peroneal muscles fatigue on dynamic stability following lateral hop landing through measuring time to stabilization (TTS) and dynamic postural stability index (DPSI). Quasi-experimental. Laboratory study. A total of 20 recreationally active, healthy males with no lower-extremity injury during the previous 6 months participated in this study. Participants performed a lateral hop on a force plate before and immediately after a fatigue intervention using a Biodex dynamometer. For inducing fatigue, the participant made a prolonged eversion effort with 40% of the maximal voluntary contraction. Fatigue was met when the eversion torque declined by 50% of the initial value. TTS and DPSI were calculated using sequential averaging method and relevant formulas, respectively. Premeasures and postmeasures of TTS in the anteroposterior, mediolateral and vertical directions, resultant vector of TTS, stability indices in the anteroposterior, mediolateral and vertical directions, and DPSI. Means of the DPSI or its components did not change significantly due to fatigue (P > .05). Means of the TTS in the anteroposterior and mediolateral directions, and the mean of the resultant vector of the TTS increased significantly after fatigue (P < .05). The question that the dynamic stability is affected or not affected by fatigue depends on which of the TTS or DPSI is used for analysis. The TTS may be a sensitive measure to detect subtle changes in postural stability due to fatigue. But, the DPSI which may be changed after a more strenuous fatigue may be related to actual fatiguing situations.

Peroneal electromechanical delay and fatigue in patients with chronic ankle instability.

The purpose of this study was to investigate the effect of chronic ankle instability (CAI) on electromechanical delay times (EMD) before and after fatigue. Understanding the mechanisms that contribute to CAI is essential for the development of effective rehabilitation programmes. It was hypothesized that patients with CAI will demonstrate prolonged EMD times compared to healthy subjects and that fatigue will cause greater increases in EMD times in the CAI group. Twenty-one male volunteers participated in the study providing data on 16 ankles with CAI and 26 with no history of ankle injury. EMD was measured on an isokinetic dynamometer. Measurements were taken with the ankle in neutral (0°) and at 30° of inversion. All subjects followed an isokinetic fatigue protocol until eversion torque fell below 50% of initial torque for three consecutive repetitions. A 2×2×2 ANOVA was used to calculate the effect of ankle status (CAI vs. healthy), fatigue, angle (0° vs. 30°) and their interactions on EMD. Fatigue caused a significant increase on EMD [non-fatigued: 122(29)ms vs. fatigue 155(54)ms; p<0.001]. EMD times were shorter at 30° of inversion compared to neutral [neutral: 145(39)ms vs. 30° of inversion: 132(40)ms, p=0.015]. An interaction effect for ankle status and angle was found (p=0.026) with CAI ankles demonstrating longer EMD [CAI: 156(45)ms vs. healthy: 133(40)ms] in neutral but not at 30° of inversion [CAI: 133(46)ms vs. 132(33)ms]. Patients with CAI had longer EMD times in neutral, but not when the ankle was placed in inversion. This suggests that rehabilitation programmes may be more effective when retraining occurs with the ankle in neutral position. It is likely that low EMD times prevent ankle acceleration at the beginning of the mechanism of injury, but they are less important when the ankle has already inverted at 30°. Both CAI and healthy subjects demonstrated longer EMD after fatigue, emphasizing the importance of proper conditioning in the prevention of delayed peroneal response and subsequent ankle injury. Improving resistance to fatigue of the peroneals may prove to be an effective prevention tool of ankle sprain recurrence in patients with CAI. III.

Lower extremity injury in female basketball players is related to a large difference in peak eversion torque between barefoot and shod conditions

BackgroundThe majority of injuries reported in female basketball players are ankle sprains and mechanisms leading to injury have been debated. Investigations into muscular imbalances in barefoot versus shod conditions and their relationship with injury severity have not been performed. The purpose of this study was to investigate the effects of wearing athletic shoes on muscular strength and its relationship to lower extremity injuries, specifically female basketball players due to the high incidence of ankle injuries in this population. MethodsDuring pre-season, 11 female collegiate basketball players underwent inversion and eversion muscle strength testing using an isokinetic dynamometer in both a barefoot and shod conditions. The difference between conditions was calculated for inversion and eversion peak torque, time to peak torque as well as eversion-to-inversion peak torque percent strength ratio for both conditions. Lower extremity injuries were documented and ranked in severity. The ranked difference between barefoot and shod conditions for peak torque and time to peak torque as well as percent strength ratio was correlated with injury ranking using a Spearman rho correlation (ρ) with an α level of 0.05. ResultsThe ranked differences in barefoot and shod for peak eversion and inversion torque at 120°/s were correlated with their injury ranking. Ranking of the athletes based on the severity of injuries that were sustained during the season was found to have a strong, positive relationship with the difference in peak eversion torque between barefoot and shod (ρ = 0.78; p = 0.02). ConclusionIt is possible that a large discrepancy between strength in barefoot and shod conditions can predispose an athlete to injury. Narrowing the difference in peak eversion torque between barefoot and shod could decrease propensity to injury. Future work should investigate the effect of restoration of muscular strength during barefoot and shod exercise on injury rates.

Free Fibula Donor-Site Morbidity

The aim of this study was the quantitative assessment of donor-site morbidity after fibula harvest. Ten patients were identified with a unilateral fibula harvesting and healthy contralateral side. The average follow-up time was 32.3 months. The study design included standardized questionnaire; morbidity point-evaluation system; orthopedic-biomechanical evaluation, including true ankle motion, clinical-functional American Orthopedic Foot and Ankle Society (AOFAS) hindfoot score, pedobarography, measurement of maximal voluntary isometric strength, and radiologic examination using an ankle osteoarthritis grading. Average donor-side morbidity score was low, with 2.6 points (range, 0 to 13). Average AOFAS hindfoot score was good, with 87.3 points (range, 74 to 100). Pedobarography showed significant decrease of the big toe pushup force. Isometric strength measurement showed significant reduction of the peroneus longus muscle. Discrete to mild medial ankle osteoarthritis was found in 70% of the cases. The overall donor-side morbidity was low, but an eversion torque deficit could initiate or support a progressive functional ankle instability and in long-term cause or accelerate a ligamentous secondary ankle osteoarthritis.

Ankle eversion torque response to sudden ankle inversion: Torque response in unbraced, braced, and pre-activated situations

In 13 young ankle stable subjects, ankle eversion torque and peroneal EMG were simultaneously recorded in response to sudden ankle inversion. The eversion torque response was bi-phasic. The initial development of torque, which was responsible for 30% of the maximal eversion torque response, was observed 135 ms after the start of platform rotation and correlated well with the onset of the automatic postural peroneal EMG response. The remaining eversion torque response commenced after 305 ms, strongly correlating with the onset of the peroneal long latency voluntary EMG activity. With the ankle unbraced, 66% of the maximal torque level was reached in 326 ms. While braced, the same torque magnitude was reached using 230 ms ( p < 0.02), and pre-activation of the peroneal muscles allowed the subjects to reach the same level of torque in 89 ms ( p < 0.0005). Prior to the study, a common reaction pattern to sudden inversion was expected in an ankle stable population, but review of the eversion torque and EMG data from the 13 subjects revealed three different voluntary reaction patterns: 10 subjects showed an efficient activation of evertor muscles; two subjects stiffened their ankles with activation of both in- and evertor muscles; and one subject showed a marginal voluntary activation of the ankle evertors. The results of the study indicate that the reaction to sudden ankle inversion is not solely automatic. The main part of the torque response is voluntarily mediated and inter-individual differences in strategy seem to exist in healthy subjects.