Ankle Eversion Research Articles

Selective Strength Training Changes the Morphology and Ankle Strength of the Peroneus Longus and the Peroneus Brevis.

This study aimed to investigate the 8-week selective training effect of the peroneus longus (PL) and the peroneus brevis (PB) on muscle morphology, echogenicity, and ankle strength and to examine post-intervention detraining effects. Twenty healthy participants without orthopedic disease in the lower extremities were assigned to either the PL intervention group (training consisted of pushing the Thera-Band® out from the ball of the foot to emphasize ankle eversion) or the PB intervention group (training consisted of pulling the Thera-Band® from the base of the fifth metatarsal to enhance ankle valgus and external rotation). Each intervention was performed three times per week for 8 weeks. The cross-sectional area (CSA), thickness, echogenicity, and ankle strength of the PL and the PB were measured before week 1 and after each training session. Detraining effects were evaluated after the 8-week intervention. The results revealed a significant interaction between within-group (week) and between-group (type of intervention) variables on CSA and ankle strength of both the PL and the PB. Over the 8-week training period, the CSA and ankle strength of the PL significantly increased in the PL intervention group, as did the CSA and ankle strength of the PB in the PB intervention group (p < 0.05). The residual effect of muscle hypertrophy was observed during the detraining period. In conclusion, 8-week selective PL and PB training interventions can increase the CSA and ankle strength of these muscles over time. Long-term selective intervention is required to improve peroneus muscle morphology and function, with separate assessments of the CSA and ankle strength of the PL and the PB.

Do Experienced Adolescent Competition Dancers Alter Landing Kinematics and Kinetics for Split Leaps or Center Leaps After Fatigue?

Most injuries that dancers sustain are to the lower extremities, specifically the foot and ankle region. Numerous potential risk factors have been examined for dancer injuries such as technical mistakes and fatigue. The purpose of this study was to compare landing kinematics and kinetics during jumps that are common in dance pre and postfatigue. Ten adolescent advanced level dancers participated in this study. Subjects completed 3 split leaps and 3 center leaps before and after a fatigue protocol performed on a stationary bike. Live motion capture was used to record landing kinematic and kinetic data. Results of this study showed a significant increase in ankle eversion and external rotation angles for center leaps from pre- to postfatigue protocol (P = .020 and P = .020, respectively) as well as significant increases in ankle eversion and knee adduction moments for center leaps (P = .020 and P = .036, respectively). These results show that after a fatigue protocol, there are changes to the kinematics of dancers that may make them more susceptible to ankle injury.

Relationship of Isokinetic Strength of Ankle Evertors and Invertors with Dynamic Postural Stability in Team Sport Players

Background: Foot stability is essential for performing various dynamic movements in sports. The contribution of ankle dorsiflexors and planter flexors co-contraction in maintenance of postural balance is mainly the focus of previous studies. However, whether there is any role of ankle evertors and invertors in maintaining foot stability while doing dynamic postural tasks is not well studied so far. Aim: The aim of this study was to find out if there is a correlation of isokinetic strength of ankle evertors and invertors with dynamic postural stability. Setting and Design: This cross-sectional study was conducted in the Strength Analysis Lab of the university. Subjects and Methods: Thirty-five male team sport players (9 – football, 9 – hockey, 9 – basketball, and 8 – volleyball) with mean age: 20.6 ± 1.83 years, body weight: 62.2 ± 8.36 kg, and height: 172.3 ± 8.07 cm were included. Balance was measured with lower quarter-Y-balance test whereas isokinetic strength of ankle evertors and invertors was measured with Biodex dynamometer. Statistical Analysis: In the statistical software SPSS, Kolmogorov–Smirnov test was applied to check the normality of data. As the data were normally distributed, the relationship between variables was found by Pearson’s correlation coefficient. Results: Isokinetic strength of right ankle invertors was moderately correlated with composite reach of the left limb at 30°/s angular velocity (P = 0.027). Composite reach right limb was moderately correlated with isokinetic strength of the right ankle evertors at 30° and 60°/s angular velocities (P = 0.043 and 0.022). Composite reach of the right limb was moderately correlated with isokinetic strength of right ankle invertors at 60° and 90°/s angular velocities (P = 0.046 and 0.046). Conclusion: Isokinetic strength of ankle evertors and invertor is significantly related to dynamic postural stability and should be included in fitness programs, especially for injury prevention and to improve dynamic postural stability.

Effects of Kinesio taping on lower limb biomechanical characteristics during unexpected jumping in patients with chronic ankle instability.

The current biomechanical research on the application of Kinesio taping (KT) to patients with chronic ankle instability (CAI) has focused on testing the expected movements. However, unexpected movements are more common in actual sports. Therefore, the present study aimed to investigate the effects of KT on the biomechanical characteristics of the knee and ankle joints during unexpected jumping movements. Twenty-one patients with unilateral CAI were recruited to capture the biomechanical parameters during unexpected jumping movements under different interventions: no taping (NT), placebo taping (PT), and KT. A one-way repeated measures analysis of variance was used to compare the differences in knee and ankle biomechanical characteristics among patients with CAI between the three intervention conditions. At initial contact, the KT group demonstrated a significant decrease in ankle plantarflexion and knee flexion angles compared to the NT group (p < 0.05). At the early landing phase, the KT group had a significant increase in peak ankle dorsiflexion angle, peak ankle eversion angle, peak ankle dorsiflexion moment, and peak ankle eversion moment compared to the NT and PT groups (p < 0.05). Furthermore, the KT group had a significantly reduced peak knee flexion angle, peak knee eversion angle, and peak vertical ground reaction force (p < 0.05) compared to the NT and PT groups. KT significantly improves the sprain-prone touchdown posture of patients with CAI. And reducing the risk of ankle sprains during the early landing phase by promoting ankle dorsiflexion and eversion angles and moments.

Immediate Effects of Ankle Eversion Taping on Balance and Gait in Recovering Stroke Patients: A Pre- Post Experimental Study

Background: Poststroke decrement in balance and gait ability disturbs daily routine of patients and increases the risk of falling. Several factors contribute to it, foot drop being one primary cause. Therefore, treating foot drop seems to be a representative approach to retain balance and gait, and the most common available options of treatment are first functional electrical stimulation (FES) and second ankle foot orthosis (AFO). However, FES and AFO are costly, inconvenient, and unattractive. Hence, to avoid these reasons, taping as an ailing method is used, because it is easily applicable and inexpensive. Aims: The aim of this study is to study and compare the effect of ankle eversion taping (AET) on balance and gait ability before and after its application. Settings and Designs: This study was conducted in the outpatient department of physiotherapy (O. P. D. 16) S. S. G. hospital, Vadodara, A pre-post experimental study. Subjects and Methods: Stroke diagnosed 50 patients participated in this study. AET consists of two stages: first of which is the application of tape for posterior talar glide and second stage is eversion taping which places ankle in more everted (neutral) position. Pre- and post-intervention assessment after an hour of an intervention scores of Berg Balance Scale and dynamic gait index were assessed and analyzed. Statistical Analysis Used: Paired t-test was to find out the efficiency of AET on balancing and gait ability in recovering patients of stroke. Results and Conclusions: Obtained P value for both the two outcomes was P &lt; 0.05 at 95% confidence interval, suggesting high significant effect. AET is effective in improving balance and gait and its parameters in recovering stroke patients.

For plantar taping, direction of elasticity matters

Plantar taping has been used in clinical settings as a short-term conservative treatment for plantar heel pain and related pathologies. The rise of at-home taping methods may offer patients more independence, but effectiveness has not been established. The purpose of this study was to evaluate the effects of plantar taping on foot mechanics during gait. We hypothesized that material compliance would drive mechanical effectiveness, with longitudinally inelastic tape reducing medial longitudinal arch (MLA) motion and anterior/posterior (A/P) plantar tissue spreading forces, and laterally inelastic tape reducing medial/lateral (M/L) tissue spreading. We also hypothesized that these effects would be influenced by foot structure. Fifteen healthy participants were tested in a randomized cross-over study design. Barefoot (BF) plus four taping methods were evaluated, including two inelastic tapes (Low-Dye, LD, and FasciaDerm, FD) along with longitudinally elastic kinesiology tape (KT) and a novel laterally elastic kinesiology tape (FAST, FS). Participants’ arch height and flexibility were measured followed by instrumented gait analysis with a multi-segment foot model. Ankle eversion and MLA drop/rise were calculated from rearfoot and forefoot reference frames, while plantar tissue spreading was calculated from shear stresses. ANOVAs with Holm pairwise tests evaluated tape effects while correlations connected arch structure and taping effectiveness (α = 0.05). The three longitudinally inelastic tapes (LD, FD, FS) reduced MLA drop by 11–15% compared with KT and BF. In late stance, these tapes also inhibited MLA rise (LD by 29%, FD and FS by 10–15%). FS and FD reduced A/P spreading forces, while FD reduced M/L spreading forces compared with all other conditions. Arch height had a moderately strong correlation (r = -0.67) with the difference in MLA drop between BF and FS. At-home plantar taping can affect the mechanical function of the foot, but tape elasticity direction matters. Longitudinally elastic kinesiology tape has little effect on mechanics, while inelastic tapes control MLA drop but also restrict MLA rise in late stance. Lateral elasticity does not limit tissue spreading and may increase comfort without sacrificing MLA control. At-home taping has the potential to broaden conservative treatment of plantar heel pain, flat foot deformity, and related pathologies, but additional studies are needed to connect mechanics with symptom relief.

Balance strategies for recovery from perturbed overground walking

Bipedal locomotion is naturally unstable and requires active control. Walking is believed to be primarily stabilized through the selection of foot placements; however, other strategies are available, including regulation of ankle inversion/eversion, ankle push-off, and angular momentum through trunk postural adjustments. The roles of these strategies in maintaining overall stability are often masked by the dominant foot placement strategy. The objectives of this study were to describe how the four strategies are used to respond to medial or lateral ground perturbations during overground walking in healthy individuals and determine reliance on each strategy. Fifteen healthy adults walked with and without perturbations applied to the right foot at heel strike while body kinematics and surface electromyographic activity were measured. Medial perturbations resulted in decreased step width on the first step after the perturbation, increased ankle inversion, increased ankle push-off, and rightward trunk sway. Lateral perturbations resulted in increased step width, decreased ankle inversion, no change in ankle push-off, and leftward trunk sway. EMG activity was consistent with the observed strategies (e.g. increased peroneus longus EMG activity during ankle eversion) with the exception of increased bilateral erector spinae activity for all perturbations. Foot placement was the dominant strategy in response to perturbations, with other strategies showing reduced, yet significant, roles. This work demonstrates that multiple strategies are recruited to improve the balance response in addition to foot placement alone. These results can serve as a reference for future studies of populations with impaired balance to identify potential deficits in strategy selection.

Individuals with chronic ankle instability show altered regional activation of the peroneus longus muscle during ankle eversion.

Individuals with chronic ankle instability (CAI) present muscular weakness and potential changes in the activation of the peroneus longus muscle, which likely explains the high recurrence of ankle sprains in this population. However, there is conflicting evidence regarding the role of the peroneus longus activity in CAI, possibly due to the limited spatial resolution of the surface electromyography (sEMG) methods (i.e., bipolar sEMG). Recent studies employing high-density sEMG (HD-sEMG) have shown that the peroneus longus presents differences in regional activation, however, it is unknown whether this regional activation is maintained under pathological conditions such as CAI. This study aimed to compare the myoelectric activity, using HD-sEMG, of each peroneus longus compartment (anterior and posterior) between individuals with and without CAI. Eighteen healthy individuals (No-CAI group) and 18 individuals with CAI were recruited. In both groups, the center of mass (COM) and the sEMG amplitude at each compartment were recorded during ankle eversion at different force levels. For the posterior compartment, the sEMG amplitude of CAI group was significantly lower than the No-CAI group (mean difference = 5.6% RMS; 95% CI = 3.4-7.6; p = 0.0001). In addition, it was observed a significant main effect for group (F1,32 = 9.608; p = 0.0040) with an anterior displacement of COM for the CAI group. These findings suggest that CAI alters the regional distribution of muscle activity of the peroneus longus during ankle eversion. In practice, altered regional activation may impact strengthening programs, prevention, and rehabilitation of CAI.

Effect of Low-Load Blood Flow Restriction Training on Patients With Functional Ankle Instability: A Randomized Controlled Trial.

Decreased muscle strength and balance in patients with functional ankle instability (FAI) can be effectively improved by ankle strength training. Low-load blood flow restriction (LL-BFR) training increases muscle size and strength, but there is limited evidence from studies on muscle strength and balance in FAI patients. To study the effects of LL-BFR training versus high-load training (HLT) on muscle strength and balance in FAI patients. Randomized controlled trial. Forty-six young adults with a history of FAI. Participants in the LL-BFR and HLT groups performed 4 sets (30 × 15 × 15 × 15) of ankle training at 20% to 40% of the one-repetition maximum and 70% to 85% one-repetition maximum, respectively, twice a week for 6weeks. Plantar flexion, dorsiflexion, inversion, and eversion muscle strength, and the Y-balance test scores were assessed at baseline and after 3 and 6weeks; the thickness of the tibialis anterior, triceps surae, and peroneus longus muscles were assessed at baseline and after 6weeks. Inversion, eversion, dorsiflexion, and plantar flexion muscle strength; tibialis anterior, triceps surae, and peroneus longus thickness; and Y-balance test scores were significantly increased in the LL-BFR group after 3 and 6weeks compared with baseline (P < .05), with no significant difference between the LL-BFR and HLT groups after 6weeks (P > .05). However, at the end of 3weeks, eversion muscle strength and Y-balance test scores were significantly higher in the LL-BFR group than in the HLT group (P < .05). Over 6weeks, LL-BFR training was as effective as HLT in improving ankle muscle strength, muscle thickness, and balance in FAI patients, but LL-BFR training improved the ankle eversion muscle strength and dynamic balance more than HLT did in the early stages of the intervention. This finding will provide a new intervention strategy for the clinical rehabilitation of FAI patients.

Influence of Double Hindfoot Arthrodesis and the Sequence of Joint Fusion on Ankle Kinematics: A Cadaveric Gait Simulation Study

Category: Ankle; Basic Sciences/Biologics Introduction/Purpose: Although double hindfoot arthrodesis (subtalar and talonavicular) provides pain relief and deformity correction for patients with end-stage arthritis, altered ankle biomechanics may occur following these procedures. Furthermore, it has been reported that hindfoot fusions may lead to progressive ankle degenerative changes and a higher failure rate in patients undergoing total ankle arthroplasty. Previous biomechanical studies demonstrated that hindfoot fusion altered ankle joint kinematics and contact mechanics during simplified loading scenarios, but the effect during dynamic activity is unknown. Therefore, this study sought to quantify the changes in ankle kinematics after a double hindfoot arthrodesis during the stance phase of simulated gait. In addition, we sought to assess whether the sequence in which joints are fused plays a role in altering ankle kinematics. Methods: Fourteen mid-tibia specimens underwent stance phase simulations of level walking using a validated six-degree of freedom robot. All specimens had neutral hindfoot alignment. An eight-camera motion system tracked reflective markers in the tibia, talus, calcaneus, and navicular bones. Simulated arthrodeses of the subtalar and talonavicular joints were performed using two 7.0mm and two 5.5mm crossing screws, respectively. The subtalar alignment was set at 5º valgus, and the talonavicular at neutral abduction/adduction. Fluoroscopic images confirmed proper screw position and hindfoot alignment. Each specimen was tested in three conditions: pre-arthrodesis(intact), isolated arthrodesis(subtalar or talonavicular joint), and double arthrodesis(double). Specimens were further divided into two groups depending on whether the subtalar(STDouble) or talonavicular(TNDouble) joint was fused first. Ankle kinematics were calculated for each condition for the entire cohort of specimens and each of the two groups. Bias-corrected 95% confidence intervals of the difference in ankle kinematics relative to the intact condition were constructed. Results: Double hindfoot arthrodesis significantly altered ankle kinematics(Figure1A). Ankle plantarflexion decreased during heel strike by up to 2.0° on average and increased during toe-off by 6.5° compared to the intact condition. Ankle eversion increased by 1.5º and 2.5º on average during mid- and late stance, respectively. Internal rotation decreased during midstance by 1.1º on average and increased in late stance by 4.5°. The order in which hindfoot joints were fused significantly influenced ankle kinematics(Figure1B). On average, the TNDouble condition produced 2.3º and 3.5º more ankle eversion during the mid- and late stance, respectively, and 2.10° more ankle internal rotation during the early stance compared to the STDouble condition (not shown). Significant changes were also present after isolated hindfoot arthrodeses and remained consistent after the double arthrodesis. Conclusion: Double hindfoot arthrodesis significantly altered ankle kinematics throughout stance. Ankle kinematics also differed depending on which joint was fused first. Notably, the TNDouble condition produced more ankle internal rotation during early stance and more ankle eversion during mid- and late stance compared to the STDouble condition. This finding suggests that the sequence in which joints are fused affects the resultant ankle kinematics. Finally, the kinematic changes after isolated hindfoot arthrodesis remained consistent after incorporating the second joint into the fusion. It appears that once one joint needs to be fused, avoiding the double arthrodesis may not necessarily protect the ankle.

Acute Effects in Selective Training of the Peroneus Longus and Peroneus Brevis

Category: Other Introduction/Purpose: The peroneal muscles undergo morphological changes and functional decline after a lateral ankle sprain, contributing to recurrence. We reported that different morphological changes occur in the peroneus longus (PL) and peroneus brevis (PB) after the lateral ankle sprain (Arima et al., 2022), and we believe that separate strength training for the PL and PB is necessary. However, the effect of selective training has not been studied. This study examined the acute effects of two different strength training interventions on PL and PB muscle morphology, one emphasizing loading on the ball of foot in PL training and the other emphasizing ankle eversion in PB training. The aim was then to determine the validity of selective strength training interventions for the peroneal muscles. Methods: Twenty healthy adults participated. Two training interventions were performed using a Thera-Band (strength: level +3 (black), Sakai Medical) in the right leg on separate days: the PL intervention in which the Thera-Band was placed on the ball of foot and pushed out from the contact point, and the PB intervention in which the Thera-Band was pushed out from the base of the fifth metatarsal. Muscle cross-sectional area (CSA) and thickness of the peroneus muscles at the proximal 25% (showing PL) and 75% (showing PB) from the line connecting the fibular head and lateral malleolus were measured with an ultrasound device. Measurements were taken before (Pre), immediately after (Post), and 10, 20, and 30 minutes after the intervention (time effect). A repeated measures two-way ANOVA was conducted to identify differences in the training effects of PL and PB interventions on PL and PB CSA, thickness. The significance level was 5%. Results: Significant main effects of time and intervention and a significant interaction between time and intervention were found in the proximal 25% and distal 75% CSA and thickness (p &lt; 0.05). For the proximal 25% CSA, only PL intervention significantly increased the CSA compared to Pre at Post, 10 and 20 minutes (p &lt; 0.05). With regard to the proximal 75% CSA, only PB intervention significantly increased the CSA compared to Pre at Post, 10 and 20 minutes (p &lt; 0.05). For the proximal 25% thickness, only PL intervention showed a significant increase in Post compared to Pre (p &lt; 0.05). Regarding proximal 75% thickness, only PB intervention significantly increased the thickness compared to Pre at Post, 10, and 20 minutes (p &lt; 0.05). Conclusion: Previous studies have reported that PL muscle activity is increased by the ball of foot loading (Ishida et al., 2011), and the PB contributes to ankle eversion compared to the PL (Otis et al., 2007). Transient muscle hypertrophy immediately after training is due to edema caused by muscle damage, indicating an acute effect of training (Damas et al., 2016). The CSA and thickness of the proximal 25% showing PL in the PL intervention and the distal 75% showing PB in the PB intervention increased immediately after those interventions in this study, suggesting the possibility of selectively training PL and PB.

Is Prehabilitation Effective on Modified Broström Procedure for Chronic Lateral Ankle Instability?

Category: Sports; Ankle Introduction/Purpose: The clinical features of chronic lateral ankle instability (CLAI) consist of mechanical and functional instability. Mechanical instability can be identified by physical examination of the injured anterior talofibular ligament laxity and can be treated with surgical ligament repair. Functional instability is more related to the patient's subjective symptoms due to decreased muscle strength, range of motion (ROM), coordination, and proprioception. In a previous report, ankle instability recurred in 16% after the modified Broström procedure (MBP) despite postoperative rehabilitation. Functional instability should be treated along with mechanical instability. We hypothesized that applying preoperative physiotherapy (prehabilitation) to patients with CLAI would improve postoperative functional recovery. We designed and performed a structured prehabilitation protocol for CLAI patients scheduled for MBP and investigated postoperative effects. Methods: Between March 2021 and December 2022, 28 patients were prospectively enrolled. Patients were randomly assigned to prehabilitation group (P) or non-prehabilitation group (N). Fourteen patients were enrolled in group P, and they started a 4-week prehabilitation protocol that continued the physiotherapy until 6 weeks postoperatively. Group N included 14 patients who received the same protocol of physiotherapy only for 6 weeks after surgery. The physiotherapy protocol consisted of peroneal muscle strengthening using Thera-band, gastro-soleus stretching, bipedal calf raises, single limb stance, step down with single limb, and box hop/quadrant hop. Outcome measurement was performed 1 day before MBP, 4 weeks and 6 weeks after surgery. The visual analogue scale, AOFAS ankle hindfoot scale, Karlsson scale, Foot and Ankle Ability Measure (FAAM-activities of daily living: ADL and FAAM-sports), Lower Extremity Functional Scale (LEFS), and ankle ROM were investigated. All data were statistically analyzed. Results: The mean ages were 27.0 ± 8.46(P), 29.7 ± 7.54(N), and there were 4 (28.6%, P) and 6 (42.9%, N) males. There were no statistical differences between the two groups in age and gender distribution. As shown in the attached table comparing clinical outcomes between the two groups, AOFAS ankle hindfoot scale, Karlsson scale, FAAM-ADL, and LEFS 1 day before MBP were statistically significantly higher in group P than in group N. Compared to group N, group P improved ankle inversion and eversion 1 day before MBP (p &lt; 0.05 each). Although there was no statistical significance, the mean of Karlsson scale, FAAM-ADL subscale, FAAM-sports subscale, and LEFS were all maintained higher in group P than in group N from before MBP to 6 weeks after surgery. Conclusion: Our findings demonstrated the importance of functional recovery along with mechanical stability in the treatment of CLAI. Functional scores tended to be maintained higher in group P than in group N from preoperative to postoperative follow-up period. However, the number of participants included in our study was relatively small at 28. Larger studies with long-time follow- up will be needed. In conclusion, a structured prehabilitation may improve functional recovery when performing MBP for CLAI.

The Association of Age and Sex With Joint Angles and Coordination During Unanticipated Cutting in Soccer Players.

Deficits in movement patterns during cutting while running might place soccer players at risk of injury. The objective was to compare joint angles and intersegment coordination between sexes and ages during an unanticipated side-step cutting task in soccer players. This cross-sectional study recruited 11 male (four adolescents and seven adults) and 10 female (six adolescents and four adults) soccer players. Three-dimensional motion capture was used to measure lower-extremity joint and segment angles as participants performed an unanticipated cutting task. Hierarchical linear models examined relationships between joint angle characteristics with age and sex. Continuous relative phase was used to quantify intersegment coordination amplitude and variability. These values were compared between age and sex groups using analysis of covariance. Adult males had greater hip flexion angle excursions than adolescent males, while adult females had smaller excursions than adolescent females (p = .011). Females had smaller changes in hip flexion angles (p = .045), greater hip adduction angles (p = .043), and greater ankle eversion angles (p = .009) than males. Adolescents had greater hip internal rotation (p = .044) and knee flexion (p = .033) angles than adults, but smaller changes in knee flexion angles at precontact compared with stance/foot off (p < .001). For intersegment coordination, females were more out-of-phase than males in the foot/shank segment in the sagittal plane. There were no differences in intersegment coordination variability between groups. Differences in joint motion during an unanticipated cutting task were present between age groups and sexes. Injury prevention programs or training programs may be able target specific deficits to lower injury risk and improve performance.

Sex Differences in Muscle Hypertrophy Response to Training of the Peroneus Longus and Peroneus Brevis Muscles

Category: Ankle; Trauma Introduction/Purpose: It has been reported that there are no significant sex differences in muscle hypertrophy response after strength training for the quadriceps muscles (Roth et al., 2002). After an ankle sprain, the peroneus longus (PL) and peroneus brevis (PB) muscles develop morphological changes and dysfunction, which requires training for the PL and PB (Arima et al., 2022). However, to our knowledge, sex differences in muscle hypertrophic response to the PL and PB training have not been studied. This study aimed to compare the changes in muscle cross-sectional area (CSA) after the PL and PB training between men and women, and to examine the possible influence of sex on the muscle hypertrophy response to training for the PL and PB. Methods: Eighteen healthy adults (9 men and 9 women) were participated. All participants performed two types of ankle eversion training on the right leg with Thera-Band on separate days. PL training in which the Thera-Band was placed on the ball of foot and pushed out from the contact point, and PB training in which the Thera-Band was pushed out from the base of the fifth metatarsal. An ultrasound imaging device was used to measure the CSA of the peroneal muscles at the proximal 25% and distal 75% of the line connecting the fibular head and the lateral malleolus. The measurements were taken before (pre), immediately after (post), 10, 20, and 30 minutes after each training, and the amount of change over time relative to pre was calculated. Unpaired t-tests were used to compare the change in CSA between men and women at each time. Statistical significance was set at 5%. Results: After the PL training, the amount of change in CSA of the PL was significantly greater by 29.7 mm² in women than in men only at post (p &lt; 0.05), but there were no significant differences at other times (10 minutes: p = 0.06, 20 minutes: p = 0.19, 30 minutes: p = 0.11). After the PB training, the amount of change in CSA of the PB was significantly greater by 16.0 mm² at post (p &lt; 0.05) and 3.1 mm² at 30 minutes (p &lt; 0.01) in women than in men. However, there were no significant differences at 10 and 20 minutes (10 minutes: p = 0.27, 20 minutes: p = 0.55). Conclusion: The results indicate that sex differences may influence the immediate muscle hypertrophic response to training for the PL and PB. The immediate muscle hypertrophy response after training is due to edema resulting from muscle damage, reflecting an immediate effect of training (Damas et al., 2016), which suggests that women are more likely to achieve effects of the PL and PB training than men in similar loads. Furthermore, the results also show that the effect of the PB training may be maintained longer in women, thus it is necessary to investigate the long-term effects of the training in the future.

Decreased rate of torque development in ankle evertors for individuals with chronic ankle instability

BackgroundIndividuals with chronic ankle instability have decreased peak torque during maximum voluntary contraction in ankle evertors/invertors, and hip abductors. However, it is unclear whether individuals with chronic ankle instability and/or copers demonstrate decreased rate of torque development in ankle evertors/invertors, and hip abductors. Methods54 university-aged participants (18 chronic ankle instability, 18 copers, and 18 controls) performed three maximal isometric contractions for ankle evertors and invertors, and hip abductors. Rate of torque development was defined as the linear slope of the torque-time curve during the first 200 ms of each contraction and compared between the three groups using a one-way analysis of variance (α = 0.05). FindingsThe chronic ankle instability group showed 38.1% less rate of torque development than the coper (P = 0.03 and d = 0.84) and 37.1% than the control groups (P = 0.03 and d = 1.03) in the ankle evertors. For the hip abductors, there were moderate effects between the chronic ankle instability group and the copers (P = 0.06 and d = 0.70), and control groups (P = 0.06 and d = 0.75). InterpretationsThe observed between-groups differences in rate of torque development indicate that restoring rate of torque development after lateral ankle sprain may be important to reduce risk of reinjury and development of chronic ankle instability. Clinicians should consider the rate of torque development in the ankle evertors and hip abductors during rehabilitation chronic ankle instability patients.

Acute Effects of Selective Strength Exercise on the Peroneus Longus and Brevis.

The peroneus muscles are muscles that mainly act in ankle eversion and can be divided into PL and PB, which have different but important roles in foot and ankle functions. Therefore, PL and PB dysfunction can lead to foot and ankle issues, making. selective strength exercise necessary. This study aimed to identify the effect of two different exercise techniques on PL and PB morphologies. Two interventions were performed on separate days: the PL intervention, in which a Thera-Band® was placed on the ball of the foot and pushed out from the contact point, and the PB intervention, in which the Thera-Band® was pulled from the base of the fifth metatarsal. Cross-sectional area (CSA) and thickness of the peroneus muscles at 25% (showing the PL morphology) and 75% (showing the PB morphology) proximal to the line connecting the fibular head and lateral malleolus, as well as ankle strength was measured before and immediately after the interventions and at 10, 20, and 30 min later. A repeated-measures two-way analysis of variance was conducted to identify differences in the effects of the interventions on the PL and PB. Main and interaction effects on CSA, thickness, and ankle strength, with a significant increase in CSA and thickness in the proximal 25% in the PL intervention and the distal 75% in the PB intervention immediately after implementation, were observed (p < 0.05). The transient increase in muscle volume due to edema immediately after exercise indicates the acute effect of exercise. The CSA and thickness of the proximal 25% in the PL intervention and the distal 75% in the PB intervention increased immediately after the intervention, indicating that these interventions can be used to selectively exercise the PL and PB.

Chronic Ankle Instability Patients Demonstrate Decreased Rate Of Torque Development In Ankle Eversion, Hip Abduction

Chronic Ankle Instability Patients Demonstrate Decreased Rate Of Torque Development In Ankle Eversion, Hip Abduction

The effect of dual-task on jump landing kinematics and kinetics in female athletes with or without dynamic knee valgus

It has been indicated that dual tasks may multiply the possibility of injuries due to divided attention. This study aimed to investigate the effect of dual-task on kinematics and kinetics of jump landing in female athletes with and without dynamic knee valgus. In this study, 32 recreational athletes between 18 and 30 years old were recruited and divided into with (n = 17) and without (n = 15) dynamic knee valgus groups. The 3-D positions of retroreflective markers were recorded at 200 Hz using a 8-camera Kestrel system (Motion Analysis Corporation, Santa Rosa, CA), while ground reaction forces were synchronously recorded at 1000 Hz using 2 adjacent force plates (FP4060-NC; Bertec Corporation, Columbus, OH). Kinematics and kinetics of jump landing were recorded while counting backward digits as a dual task, and also without counting backward digits as a single task. One-way repeated measures of variance were used to analyse data at the significant level of 95% (α < 0.05). The study found that the dual-task affected the angles and moments of hip, knee, and ankle joints (P < 0.05) in both groups. Additionally, the effect of the dual-task differed significantly between the two groups in the angles hip flexion (P < 0.001), knee abduction (P < 0.001), and ankle internal rotation (P = 0.001), as well as the moments hip flexion (P < 0.001), hip abduction (P = 0.011), knee flexion (P = 0.017), knee internal rotation (P < 0.001), ankle dorsiflexion (P = 0.046), ankle eversion (P < 0.001), and ankle internal rotation (P = 0.046). Athletes with dynamic knee valgus may have been less able to protect themselves during the landing and are more prone to lower extremities injuries. As a result, using kinematics and kinetics in athletes with dynamic knee valgus during landing may help identify potential mechanisms associated with risk factors of lower extremity injuries and ACL injuries as well.

The clinical and biomechanical effects of customized foot orthoses in individuals with plantar heel pain: A pre-post intervention study

BackgroundCustomized foot orthoses (CFOs) are often recommended for the management of plantar heel pain. However, there is a lack of information regarding lower limb and multi-segment foot motion during gait. Research questionThis study aimed to determine the effects of heat moulded CFOs on foot and lower limb kinematics when compared with prefabricated foot orthoses (PFOs) and wearing no orthoses (shod condition), and to determine the short-term effects of CFOs on pain intensity and foot function. MethodsThe immediate effects of CFOs on the lower limb and multi-segment foot motion were assessed. Participants were then asked to use the CFOs for one month and foot pain, function, and temporal-spatial parameters were assessed at baseline and at one month follow up. ResultsThirty-five participants (22 females), aged 40.1 (10.5) years, with a mean duration of symptoms of 12.59 months were recruited. The symptomatic limbs showed a higher forefoot varus angle and greater rearfoot and forefoot corrections were required compared to the non-symptomatic limbs. When compared with PFOs and shod conditions, CFOs provided the least forefoot and knee motion in the transverse plane during contact phase (P < 0.05, d=0.844–1.720), least rearfoot motion in the coronal plane during midstance (P < 0.05, d=0.652), and least forefoot motion in the frontal plane, knee motion in the transverse plane, and hallux motion during the propulsive phase (P < 0.05, d=0.921–1.513). Significant improvements were seen for foot pain and function (P < 0.05, d=1.390–2.231) with significant increases in cadence and walking velocity after one month of CFO use (P < 0.05, d=0.315–0.353), and those most likely to respond had greater pain and less ankle eversion (P < 0.05, d=0.855–1.115). SignificanceCFOs appear to improve pathological biomechanics associated with plantar heel pain. After one month follow up, the CFOs decreased pain intensity and increased foot function, and showed significant improvements in temporal and spatial parameters of gait.

Two-Dimensional and Three-Dimensional Biomechanical Factors During 90° Change of Direction are Associated to Non-Contact ACL injury in Female Soccer Players.

The two-dimensional (2D) video-analysis of the change of direction (COD) technique has never been used to attempt to predict the risk of ACL injury in female football players. The purpose of the present pilot study was to prospectively investigate the biomechanical predictors of ACL injury during a COD task in female football players using both gold standard 3D motion capture and a qualitative scoring system based on 2D video-analysis. Prospective cohort study. Sixteen competitive female football (soccer) players (age 21.4 ± 4.3) performed a series of pre-planned 90° COD tasks. 3D motion data was recorded through 10 stereophotogrammetric cameras and a force platform. 2D frontal and transverse plane joint kinematics were computed through video-analysis from three high-speed cameras. A scoring system based on five criteria was adopted: limb stability, pelvis stability, trunk stability, shock absorption, and movement strategy. The players were prospectively followed for the next two consecutive football seasons and the occurrence of severe knee injuries was registered. Four players (25%) experienced an ACL injury. In 3D analysis, ACL-injured players showed greater knee valgus, knee internal rotation, and lower knee flexion (p= 0.017 - 0.029). Lower hip flexion coupled with greater external rotation (p= 0.003 - 0.042), ankle eversion, and contralateral pelvic drop (p<0.001) were also noted. In 2D analysis, ACL-injured players showed greater internal foot rotation, contralateral pelvic drop, lower knee flexion, and contralateral trunk tilt (moderate-to-large effect size). Pelvis stability and trunk stability showed the highest predictive value towards ACL injury. Total score was significantly lower in ACL-injured players with a moderate effect size (d=0.45). Both 3D and 2D methodologies depicted biomechanical risk factors and offered predictive insights towards the ACL injury risk. Awareness should rise in women's football regarding the high risk of ACL injury and the strategies to assess and mitigate it. 3©The Author(s).