Lower extremity kinematics and ground reaction forces after prophylactic lace-up ankle bracing

Influence of Torsional Stiffness in Badminton Footwear on Lower Limb Biomechanics

Torsional stiffness of athletic footwear plays a crucial role in preventing injury and improving sports performance. Yet, there is a lack of research focused on the biomechanical effect of torsional stiffness in badminton shoes. This study aimed to comprehensively investigate the influence of three different levels of torsional stiffness in badminton shoes on biomechanical characteristics, sports performance, and injury risk in badminton players. Fifteen male players, aged 22.8 ± 1.96 years, participated in the study, performing badminton-specific tasks, including forehand clear stroke [left foot (FCL) and right foot (FCR)], 45-degree sidestep cutting (45C), and consecutive vertical jumps (CVJ). The tasks were conducted wearing badminton shoes of torsional stiffness measured with Shore D hardness 50, 60, and 70 (referred to as 50D, 60D, and 70D, respectively). The primary biomechanical parameters included ankle, knee, and MTP joint kinematics, ankle and knee joint moments, peak ground reaction forces, joint range of motion (ROM), and stance time. A one-way repeated measures ANOVA was employed for normally distributed data and Friedman tests for non-normally distributed data. The 70D shoe exhibited the highest ankle dorsiflexion and lowest ankle inversion peak angles during 45C task. The 60D shoe showed significantly lower knee abduction angle and coronal motions compared to the 50D and 70D shoes. Increased torsional stiffness reduced stance time in the FCR task. No significant differences were observed in anterior-posterior and medial-lateral ground reaction forces (GRF). However, the 70D shoe demonstrated higher vertical GRF than the 50D shoe while performing the FCR task, particularly during 70% - 75% of stance. Findings from this study revealed the significant role of torsional stiffness in reducing injury risk and optimizing performance during badminton tasks, indicating that shoes with an intermediate level of stiffness (60D) could provide a beneficial balance between flexibility and stability. These findings may provide practical references in guiding future badminton shoe research and development. Further research is necessary to explore the long-term effects of altering stiffness, considering factors such as athletic levels and foot morphology, to understand of the influence of torsional stiffness on motion biomechanics and injury prevalence in badminton-specific tasks.

Effect of lace-up ankle brace on the tibiotalar and subtalar joint during the landing

Objective: Ankle braces can affect the kinematics of the ankle joint during landing tasks. Previous studies were primarily relied on traditional marker-based motion capture systems, which pose limitations in non-invasively capturing the motion of the talus bone. The effect of ankle braces on the in vivo kinematics of the tibiotalar and subtalar joints during landing remains unknown. This study used a high-speed dual fluoroscopic imaging system (DFIS) and magnetic resonance imaging (MRI) to investigate effect of ankle braces on the in vivo kinematics of the tibiotalar and subtalar joints during landing. Methods: Fourteen healthy participants were recruited for this study. During the experiment, static three-dimensional MRI data were collected for each participant, and 3D ankle joint models for the calcaneus, talus, and tibia were constructed. The DFIS was used to capture the images of each participant performing a single-leg landing-jump task at a height of 40 cm. The images were captured once with and without a brace in the fatigue condition, which was induced by running. The six-degree-of-freedom (6DOF) kinematic data were obtained by 2D-3D registration. Results: The flexion-extension range of motion (ROM) (42.73 ± 4.76° vs. 38.74 ± 5.43°, p = 0.049) and anterior-posterior translation ROM (16.86 ± 1.74 mm vs. 15.03 ± 1.73 mm, p = 0.009) of the tibiotalar joint were decreased. The maximum inversion angle (-3.71 ± 2.25° vs. 2.11 ± 1.83°, p = 0.047) of the subtalar joint was decreased. Conclusion: The ankle brace limited the flexion-extension ROM of the tibiotalar joints and the inversion angle of the subtalar joint during landing.

Single Knotless Suture Anchor Repair of Anterior Talofibular Ligament Following Distal Fibula Nonunion Excision

Anterior talofibular ligament (ATFL) tear is the most common ankle ligament injury. This can lead to recurrent ankle instability, which is detrimental to ankle function and the patient's quality of life. Currently, several techniques have shown successful outcomes for ATFL repair. In this technical note, we describe an open ATFL repair using a single knotless suture anchor at the distal fibula location. This approach is rapid, equipment-efficient, and reproducible, while promising excellent results and high patient satisfaction by restoring ATFL anatomy.

Six-Week Remodeled Bike Pedal Training Improves Dynamic Control of Lateral Shuffling in Athletes With Functional Ankle Instability

BACKGROUND

Remodeled bicycle pedal training with multidirectional challenges through muscle strengthening and neuromuscular facilitation may increase dynamic postural control and performance during lateral shuffling for athletes with functional ankle instability (FAI).

HYPOTHESIS

The 6-week remodeled bicycle pedal training is effective on the ankle joint control and muscle activation, and especially that of the ankle evertor muscle co-contraction to improve dynamic postural control during lateral shuffling for athletes with FAI.

STUDY DESIGN

Laboratory randomized controlled trial.

LEVEL OF EVIDENCE

Level 2.

METHODS

Fourteen healthy athletes (healthy group) and 26 athletes with FAI aged 18 to 30 years were included in the study. The athletes with FAI were randomly assigned to either the training group (FAI-T group) or the nontraining group (FAI-NT group). The athletes in the FAI-T group underwent 6 weeks of remodeled bicycle pedal training, whereas those in the FAI-NT group did not undergo any intervention. Muscle co-contraction index and muscle activation in the initial contact (IC) and propulsion phases, and ankle joint angle in the IC and propulsion phases were measured during lateral shuffling before and after 6 weeks of training.

RESULTS

After remodeled bicycle pedal training, the FAI-T group demonstrated greater muscle activation in the hamstring (P = 0.01), greater muscle coactivation of the tibialis anterior (TA) and the peroneus longus (P = 0.01), and greater ankle eversion angle in the IC phase. Significantly greater muscle activation of the TA (P = 0.01), greater coactivation of quadriceps and hamstring (P = 0.03), and a smaller ankle inversion angle (P = 0.04) in the propulsion phase were observed in the FAI-T group after training compared with those in the FAI-NT group.

CONCLUSION

Remodeled bicycle pedal training facilitates the TA and peroneus longus activation and the coactivation of the quadriceps and hamstring muscles during lateral shuffling and resulted in enhanced ankle and knee joint stability. In addition, a better ankle movement strategy during a dynamic task can be achieved via a 6-week remodeled pedal training program.

CLINICAL RELEVANCE

This remodeled bicycle pedal training can be effective for rehabilitating athletes with FAI to recover lateral dynamic movement capability.

Prophylactic ankle supports effects on time to stabilization, perceived stability and ground reaction force during lateral landing in female collegiate athletes with chronic ankle instability

Background

This study was designed to investigate effects of Kinesiotape (KT) with closed basket weave method and lace-up braces (LB) on the vertical time to stabilization, peak vertical ground reaction force (PvGRF), and time to PvGRF as well as perceived stability during lateral landing of participants with chronic ankle instability before and after fatigue.

Methods

Thirty female college athletes with chronic ankle instability of three conditions (control, KT, and LB) performed lateral landing from a 30 cm high step on the plantar pressure platform pre and post fatigue.

Results

The pre-test findings on the rearfoot, of LB indicated negatively increased the PvGRF force (F_2,58=3.63, P = 0.04) and decreased the time to PvGRF (F_2,58=4.67, P = 0.01). The Bonferroni post-hoc testing revealed LB condition increased the PvGRF than the control (P = 0.002) and KT (P = 0.038). Also, the post-hoc testing showed LB condition decreased the time to PvGRF force than the control (P = 0.05) and KT (P = 0.01). The LB negatively prolonged vertical time to stabilization in the forefoot (F_2,58=6.74, P = 0.002) and rearfoot (F_2,58=6.13, P = 0.004) after fatigue. The post-hoc testing revealed LB condition generated a slower vertical time to stabilization than the control and KT conditions (P ≤ 0.05). The use of KT had no positive effects as elevated the PvGRF in the forefoot post fatigue (F_2,58=7.11, P = 0.002). The post-hoc test uncovered that KT augmented the PvGRF than control (P = 0.01) and LB (P < 0.001). On the other hand, using KT had psychological effects at pre-fatigue which resulting significantly greater in perceived stability compared to other conditions (F_2,58=9.65, P < 0.001). The post-hoc test showed that using KT increased perceived stability than LB (P = 0.004) and control (P < 0.001). Moreover, perceived stability improved significantly in KT and LB compared to the control condition at the post-fatigue (P ≤ 0.001).

Conclusions

Despite the positive psychological impact of the prophylactic ankle supports, there were no positive effect on the vertical time to stabilization, PvGRF, and time to PvGRF. Further studies are needed to distinguish the psychological and actual effects of prophylactic ankle supports on athletes with chronic ankle instability.

EFFECTS OF WEARING AN ANKLE BRACE ON GROUND REACTION FORCES DURING JUMPS IN BASKETBALL GAME SIMULATION

ABSTRACT Introduction: The use of ankle braces reduces the risk of ankle injuries in basketball players. However, the mechanisms of injury protection provided by the ankle braces in the basketball game are still unknown. Objectives: To analyze the effects of wearing a lace-up ankle brace, and to conduct an exercise protocol that simulated the intensity of the basketball game on ground reaction force (GRF) during basketball-specific vertical jumps. Methods: Eleven male younger basketball players aged under 18 completed 48 vertical jumps, with and without ankle braces, during an exercise protocol composed of four 10-minute periods, simulating the activity profile and intensity of the basketball game as well as the typical intervals between periods. Mediolateral (variables: the greatest medial and lateral peaks) and vertical (variables: vertical peak, impulse peak, impulse at 50 ms of landing, loading rate and jump height) GRF were measured during takeoff and landing for all the jumps performed in the exercise protocol. Results: The use of the ankle brace reduced mediolateral GRF in all periods of the exercise protocol during takeoff and landing ( P < 0.05), without affecting the vertical GRF ( P > 0.05). Mediolateral and vertical GRF (takeoff mediolateral vertical peaks, landing mediolateral peaks, landing impulse peak, takeoff and landing loading rate) increased significantly during four subsequent 10-minute periods ( P < 0.05). However, for mediolateral GRF, the increase overtime was higher without braces. Conclusions: The use of the ankle brace reduced the mediolateral GRF on the lower limb, while there was a progressive increase in the external load applied to the body during the vertical jumps in the subsequent periods of the exercise protocol performed at the same intensity of the basketball game. Level of evidence I; Randomized clinical trial .

Restricting ankle dorsiflexion does not mitigate the benefits of external focus of attention on landing biomechanics in healthy females

PURPOSE

Restricted ankle dorsiflexion can promote aberrant biomechanics associated with risk for knee injury during dynamic activities. Attentionally focused instructions have been used to improve high-risk knee biomechanics during landing tasks. Yet, it is unknown whether attentionally focused instruction can effectively improve landing patterns in the presence of a mechanical restriction on the ankle. Therefore, our purpose was to determine whether restricting ankle dorsiflexion by use of bracing mitigated the effects of attentional foci on landing biomechanics in healthy females.

METHODS

We used a crossover design to investigate lower extremity biomechanics in 19 healthy females between the ages of 18-35 during a series of jump-landing tasks. Participants completed 6 blocks of 3 jump-landings on separate force platforms in a randomized order based on brace condition (brace, no brace) and mode of attentional foci (neutral, internal focus [IF], external focus [EF]). Attentionally focused instructions were provided immediately prior to 3 practice jump-landings, followed by 5 test jump-landings with self-controlled feedback only.

RESULTS

Ankle bracing decreased peak dorsiflexion and sagittal range of motion (ROM) (mean difference: 5.7-5.8°), and peak inversion and frontal ROM (mean difference: 2.4-3.0°). However, hip flexion ROM (mean difference: 1.8°) increased compared to the no brace condition. Regardless of ankle bracing, EF instruction increased peak hip flexion (mean difference: 4.9°) and hip flexion range of motion (mean difference: 3.8-4.6°), while decreasing peak knee valgus (mean difference: 0.8-1.0°) and knee valgus moment (mean difference: 0.04 Nm/kg). Additionally, EF instruction increased peak hip abduction to a similar degree when braced (mean difference: 3.6-4.0°) and not braced (mean difference: 2.1-2.5°). Lastly, EF instruction increased hip abduction ROM only when braced (mean difference: 2.3-2.4°), but decreased peak knee valgus power only when not braced (mean difference: 0.18 W/kg).

CONCLUSIONS

Our findings indicate that mechanically restricting ankle dorsiflexion does not mitigate the ability of EF instruction to enhance jump-landing performance by means of improving hip and knee biomechanics in healthy females. However, our findings suggest an improved ability to control the rate of knee valgus loading when not braced. Therefore, we conclude that EF instruction remains a viable clinical strategy to improve landing patterns in the presence of restricted ankle dorsiflexion, yet this approach may be ineffective to reduce the rate of knee joint loading.

Passive Exercise Adaptation for Ankle Rehabilitation Based on Learning Control Framework

Ankle injuries are among the most common injuries in sport and daily life. However, for their recovery, it is important for patients to perform rehabilitation exercises. These exercises are usually done with a therapist's guidance to help strengthen the patient's ankle joint and restore its range of motion. However, in order to share the load with therapists so that they can offer assistance to more patients, and to provide an efficient and safe way for patients to perform ankle rehabilitation exercises, we propose a framework that integrates learning techniques with a 3-PRS parallel robot, acting together as an ankle rehabilitation device. In this paper, we propose to use passive rehabilitation exercises for dorsiflexion/plantar flexion and inversion/eversion ankle movements. The therapist is needed in the first stage to design the exercise with the patient by teaching the robot intuitively through learning from demonstration. We then propose a learning control scheme based on dynamic movement primitives and iterative learning control, which takes the designed exercise trajectory as a demonstration (an input) together with the recorded forces in order to reproduce the exercise with the patient for a number of repetitions defined by the therapist. During the execution, our approach monitors the sensed forces and adapts the trajectory by adding the necessary offsets to the original trajectory to reduce its range without modifying the original trajectory and subsequently reducing the measured forces. After a predefined number of repetitions, the algorithm restores the range gradually, until the patient is able to perform the originally designed exercise. We validate the proposed framework with both real experiments and simulation using a Simulink model of the rehabilitation parallel robot that has been developed in our lab.

Is an Elastic Ankle Support Effective in Improving Jump Landing Performance, and Static and Dynamic Balance in Young Adults With and Without Chronic Ankle Instability?

CONTEXT

In some patients, ankle sprains lead to chronic symptoms like pain or muscular weakness called chronic ankle instability (CAI). External ankle supports have shown to be effective in preventing sprains and reducing recurrence, but the underlying mechanisms are unclear. As sensorimotor variables are associated with injury incidence, an influence of external ankle support on landing performance and balance seems plausible.

OBJECTIVE

To analyze the effects of an elastic ankle support on jump landing performance and static and dynamic balance in patients with CAI and healthy controls.

DESIGN

Crossover study.

SETTING

Functional tests in a laboratory setting.

PATIENTS OR OTHER PARTICIPANTS

Twenty healthy students and 20 patients with CAI were included for study participation based on their scores in ankle stability and function questionnaires.

INTERVENTION

Healthy and CAI participants performed each test with and without an elastic ankle support.

MAIN OUTCOME MEASURES

(1) Jump landing performance was measured with the Landing Error Scoring System, (2) static balance was assessed with the Balance Error Scoring System, and (3) dynamic balance was assessed using the Y Balance Test. Linear mixed models were used to analyze the effects of the elastic ankle support on sensorimotor parameters.

RESULTS

Healthy controls performed significantly better in the Landing Error Scoring System (P = .01) and Y Balance Test anterior direction (P = .01). No significant effects of elastic ankle support on Landing Error Scoring System, Balance Error Scoring System, or Y Balance Test performance were observed in the CAI or control group. There were no significant group-by-ankle support interactions.

CONCLUSIONS

In the current study, the acute use of elastic ankle support was ineffective for enhancing jump landing performance, and static and dynamic balance. Further research is needed to identify the underlying mechanisms of the preventive effects of elastic ankle support.

Effects of 4-week impairment-based rehabilitation on jump-landing biomechanics in chronic ankle instability patients

OBJECTIVE

To determine effects of 4-weeks of impairment-based rehabilitation on lower extremity neuromechanics during jump-landing.

DESIGN

Descriptive laboratory study.

PARTICIPANTS

Twenty-six CAI subjects (age = 21.4 ± 3.1 sex=(M = 7,F = 19), height = 169.0 ± 8.8 cm, weight = 71.0 ± 13.8 kg) completed 15 jump-landing trials prior to and following 12 supervised rehabilitation sessions.

MAIN OUTCOME MEASURES

Frontal and sagittal lower extremity kinematics and kinetics and sEMG amplitudes (anterior tibialis, peroneus brevis, peroneus longus, and medial gastrocnemius). Means and 90% confidence intervals (CIs) were calculated for 100 ms prior to and 200 ms following ground contact. Areas where pre- and post-rehabilitation CIs did not overlap were considered significantly different. Kinematic and kinetic peaks and kinematic excursion were compared with paired t-test (P ≤ 0.05).

RESULTS

Following rehabilitation, CAI subjects exhibited less ankle (2.1° (0.8, 3.4), P < 0.01) and hip (2.0° (0.5, 3.7), P = 0.01) frontal plane excursion and lower peak hip abduction (2.5° (0.0, 5.0), P = 0.05). There was less ankle (5.0° (1.7, 8.3), P < 0.01) and knee (3.4° (0.8, 6.0), P = 0.01) sagittal plane excursion following rehabilitation. There was decreased peroneus longus activity from 9 ms to 135 ms post ground contact and decreased peak plantar flexion moment (0.08 N∗m/kg (0.01, 0.13), P = 0.02) following rehabilitation.

CONCLUSION

Progressive impairment-based rehabilitation resulted in reductions in kinematic excursion and peroneus longus muscle activity, suggesting a more efficient landing strategy.

The effect of silicone ankle sleeves and lace-up ankle braces on neuromuscular control, joint torque, and cutting agility

Objective

To evaluate the effects of silicone ankle sleeves (SASs) and lace-up ankle braces (LABs) on neuromuscular control, net joint torques, and cutting agility in healthy, active individuals.

Design

Markerless motion-capture technology tracked subjects fitted with SASs, LABs, or no brace while they performed the movements: Y-excursion, left cutting, right cutting, single-leg drop vertical jump (SLDVJ), 45-degree bound, and single-leg squat (SLS).

Setting

University Laboratory.

Participants

Ten healthy, active individuals (5 males and 5 females, mean ± SD 23.60 ± 1.43 years of age).

Main outcome measures

Degrees of joint range of motion (ROM), Newton-meters of joint torque, time to perform a cutting maneuver.

Results

SASs and LABs resulted in significantly different knee and ankle ROM and hip internal rotation in the SLDVJ, SLS, Y-excursion, cutting maneuver, and 45-degree bound when compared to control (p < .05). Both ankle and knee torque were significantly reduced in the 45-degree bound and cutting movements with both types of PABs (p < .05). There were minimal differences between the SASs and LABs for all conditions. There were no statistically significant differences in cutting times for any of the 3 conditions.

Conclusion

Both SAS and LAB positively impacted neuromuscular control, reduced net joint torque, and neither impaired cutting agility when compared to control.

Ankle bracing's effects during a modified agility task: analysis of sEMG, impulse, and time to complete using a crossover, repeated measures design

This study explored the effects of no braces, softshell (AE), and semi-rigid (T1) ankle braces on time to complete a modified agility task, as well as lower extremity muscle activity and impulse during the change of direction component of the task. Thirty-nine healthy, active individuals completed a modified agility task under the three brace conditions. Time to complete the modified agility task, along with mean surface electromyographic activity (sEMG) and impulse during the deceleration and propulsive phases of the task were measured. There were no significant differences across conditions with respect to sEMG or impulse measures during the deceleration or propulsive phases. There was a significant change in time to complete the modified agility task, F(2,76) = 17.242, p< 0.001, ηp² = 0.312. Post-hoc analysis revealed a significant increase in time to complete the modified agility task when wearing the AE (0.16 (95% CI, 0.062 to 0.265) seconds, p< 0.001) and T1 (0.20 (95% CI, 0.113 to 0.286) seconds, p< 0.001) ankle braces compared to no braces. It appears that performance on a modified agility task may be diminished when wearing ankle braces, although sEMG activity and impulse are unaffected.

Influence of Foot-Landing Positions at Initial Contact on Knee Flexion Angles for Single-Leg Drop Landings

Purpose: Small knee flexion angles are associated with increased non-contact anterior cruciate ligament (ACL) injury risks. The purpose of this study was to provide insights into how ankle plantar flexion angles influenced knee flexion angles at initial contact during single-leg drop landings. Method: Thirteen male recreational basketball players performed single-leg drop landings from a 30-cm high platform using three randomized foot-landing positions (natural, fore-foot, and flat-foot). A motion capture system and a force plate were used to measure lower extremity kinematics and vertical ground reaction force (VGRF). A one-way repeated measures Analysis of Variance and the Friedman test were conducted (α = .05). Results: Foot-landing position had a significant effect on knee flexion angles at initial contact (p < .001). As compared to flat-foot landings (18° (SD 5°), significantly smaller knee flexion angles were found for natural (mean 12° (SD 5°), p = .004) and fore-foot landings (mean 12° (SD 3°), p = .001). There was however significantly smaller knee flexion range of motion in flat-foot landings (mean 42° (SD 3°), as compared to natural landings (mean 48° (SD 4°) (p < .001). Flat-foot landings also resulted in a 1.4 times higher maximum VGRF than fore-foot landings (p < .001) and 1.3 times higher than natural landings (p = .005). Conclusions: Natural and fore-foot landings are better for force absorption but are associated with smaller knee flexion angles at initial contact. These findings have important implications for non-contact ACL injuries.

Ankle Bracing Alters Coordination and Coordination Variability in Individuals With and Without Chronic Ankle Instability

CONTEXT

Ankle bracing is an effective form of injury prophylaxis implemented for individuals with and without chronic ankle instability, yet mechanisms surrounding bracing efficacy remain in question. Ankle bracing has been shown to invoke biomechanical and neuromotor alterations that could influence lower-extremity coordination strategies during locomotion and contribute to bracing efficacy.

OBJECTIVE

The purpose of this study was to investigate the effects of ankle bracing on lower-extremity coordination and coordination dynamics during walking in healthy individuals, ankle sprain copers, and individuals with chronic ankle instability.

DESIGN

Mixed factorial design.

SETTING

Laboratory setting.

PARTICIPANTS

Forty-eight recreationally active individuals (16 per group) participated in this cross-sectional study.

INTERVENTION

Participants completed 15 trials of over ground walking with and without an ankle brace.

MAIN OUTCOME MEASURES

Coordination and coordination variability of the foot-shank, shank-thigh, and foot-thigh were assessed during stance and swing phases of the gait cycle through analysis of segment relative phase and relative phase deviation, respectively.

RESULTS

Bracing elicited more synchronous, or locked, motion of the sagittal plane foot-shank coupling throughout swing phase and early stance phase, and more asynchronous motion of remaining foot-shank and foot-thigh couplings during early swing phase. Bracing also diminished coordination variability of foot-shank, foot-thigh, and shank-thigh couplings during swing phase of the gait cycle, indicating greater pattern stability. No group differences were observed.

CONCLUSIONS

Greater stability of lower-extremity coordination patterns as well as spatiotemporal locking of the foot-shank coupling during terminal swing may work to guard against malalignment at foot contact and contribute to the efficacy of ankle bracing. Ankle bracing may also act antagonistically to interventions fostering functional variability.

THE INFLUENCE OF HEEL HEIGHT ON MUSCLE ELECTROMYOGRAPHY OF THE LOWER EXTREMITY DURING LANDING TASKS IN RECREATIONALLY ACTIVE FEMALES: A WITHIN SUBJECTS RANDOMIZED TRIAL

BACKGROUND

An increased risk of ACL injury has been shown in female athletes who land from jumping maneuvers with knee angles close to extension and in those who demonstrate a hamstring-to-quadriceps muscle recruitment imbalance.

HYPOTHESIS/PURPOSE

The purpose of this study was to determine if added heel lift height would alter electromyography (EMG) magnitude and timing of the quadriceps (vastus medialis, vastus lateralis), hamstrings (semitendinosus, biceps femoris) and gastroc (medial gastroc, lateral gastroc) musculature during forward jump and drop-rebound jump landing tasks in females. The authors hypothesized increased heel lift height would promote recruitment of the hamstring and gastrocnemius muscles and increase the time to peak muscle activity in the quadriceps muscles.

STUDY DESIGN

Prospective randomized trial.

METHODS

60 recreationally active females participated. Participants performed five repetitions of forward jump and drop-rebound jump landing tasks while wearing different heel lifts heights (0, 12, 18, 24 mm) placed on the under-side of an athletic shoe. Task order and heel lift height were randomized. Dependent measures were average magnitude of muscle recruitment (AMR), peak magnitude of muscle recruitment (PMR), and time to reach PMR for six lower extremity muscle groups as measured by surface EMG.

RESULTS

Repeated measures ANOVAs were used to determine the influence of heel lift height on the dependent measures. There were no signficant differences in the AMR, PMR, or time to reach PMR with the four different heel heights during the landing maneuvers, with one exception. A significant difference was found in the time to achieve PMR in the semitendinosis muscle during a forward jump landing (p = .024). Post hoc analysis found significant differences with both the 18mm and 24mm heel lift height compared to 0mm.

CONCLUSIONS

Utilization of larger heel lifts (18mm and 24mm) to influence landing biomechanics may be of potential benefit; however, only when performing forward jump landing tasks. Further investigation into the protective effects of a quicker onset of semitendinosis peak magnitude is warranted.

LEVEL OF EVIDENCE

2.

The Influence of Ankle Braces on Functional Performance Tests and Ankle Joint Range of Motion

CONTEXT

The lateral ankle sprain is one of the most common lower-extremity injuries in sports. Previous research has found that some prophylactic ankle supports reduce the risk of recurrent ankle sprains and provide extra support to the joint. However, there is a continued concern that these supports may negatively influence performance.

OBJECTIVE

To determine if wearing an ankle brace influences athlete performance and ankle kinematics during functional performance tests.

DESIGN

Repeated measures.

SETTING

University gymnasium.

OTHER PARTICIPANTS

Male and female recreational or competitive athletes (n = 20).

INTERVENTION

Participants performed 3 trials of a standing long jump, vertical jump, 40-yard sprint, and T-drill under each of the following 3 conditions: wearing traditional lace-up brace (brace 1), modified lace-up brace (brace 2), and no-brace.

MAIN OUTCOME MEASURES

A 2-dimensional motion capture camera was used to measure ankle range of motion (ROM) in the sagittal plane during the vertical and standing long jumps and in the frontal plane during the cutting phase of the T-drill. Performance of each test and ankle ROM were compared between each of the braced conditions.

RESULTS

Ankle braces did not influence performance in speed or agility functional performance tests (P > .05). Ankle braces negatively affected performance of the standing long jump (P = .01) and vertical jump (P = .01). There was no significant difference between brace or no-brace conditions in ankle inversion ROM during the T-drill (P > .05). Both brace conditions restricted ROM in the sagittal plane during the vertical and standing long jumps (P < .05).

CONCLUSIONS

Braced conditions restricted sagittal plane ROM during the vertical jump and long jump. This decrease in ROM explains the decline in functional performance also seen during these tests.

Ultrasonography of Gluteal and Fibularis Muscles During Exercises in Individuals With a History of Lateral Ankle Sprain

CONTEXT

Individuals with a history of lateral ankle sprains (LASs) have ankle and hip neuromuscular changes compared with those who do not have a history of LAS.

OBJECTIVE

To compare gluteus maximus (GMax), gluteus medius (GMed), and fibularis longus and brevis muscle activation using ultrasound imaging during tabletop exercises and lateral resistance-band walking in individuals with or without a history of LAS or chronic ankle instability (CAI).

DESIGN

Cross-sectional study.

PATIENTS OR OTHER PARTICIPANTS

Sixty-seven young adults (27 males, 40 females). Groups were healthy = 16, coper = 17, LAS = 15, CAI = 19. The number of previous sprains was 0 ± 0 in the healthy group, 1.1 ± 0.3 in the coper group, 2.9 ± 2.4 in the LAS group, and 5.3 ± 5.9 in the CAI group.

MAIN OUTCOME MEASURE(S)

Ultrasound imaging measures of fibularis cross-sectional area (CSA) were collected during nonresisted and resisted ankle eversion. Gluteal muscle thicknesses were imaged during nonresisted and resisted side-lying abduction and during lateral resistance-band walking exercises (lower leg and forefoot band placement). Separate 4 × 2 repeated-measures analyses of variance and post hoc Fisher least significant difference tests were used to assess activation across groups and resistance conditions.

RESULTS

All groups demonstrated 3.2% to 4.1% increased fibularis CSA during resisted eversion compared with nonresisted. During side-lying abduction, the LAS and CAI groups displayed increased GMax thickness (6.4% and 7.2%, respectively), and all but the CAI group (-0.4%) increased GMed thickness (5.3%-11.8%) with added resistance in hip abduction. During band walking, the healthy and LAS groups showed increased GMax thickness (4.8% and 8.1%, respectively), and all groups had increased GMed thickness (3.0%-5.8%) in forefoot position compared with the lower leg position. Although the values were not different, copers exhibited the greatest amount of GMed thickness during band-walking activities (copers = 23%-26%, healthy = 17%-23%, LAS = 11%-15%, CAI = 15%-19%).

CONCLUSIONS

All groups had increased fibularis CSA with resisted eversion. In side-lying hip abduction, individuals with CAI had greater GMax thickness than GMed thickness. Ultrasound imaging of fibularis CSA and gluteal muscle thickness may be clinically useful in assessing and treating patients with LAS or CAI.

Effects of an ankle brace on the in vivo kinematics of patients with chronic ankle instability during walking on an inversion platform

BACKGROUND

As in vivo tibiotalar and subtalar joint kinematics are not currently known following the application of an ankle brace, an investigation of these kinematics may provide insight into the mechanisms of ankle braces.

RESEARCH QUESTION

This study aimed to determine the effect of an ankle brace on in vivo kinematics of patients with chronic ankle instability.

METHODS

Eleven patients with chronic ankle instability were recruited in this study. A dual fluoroscopic imaging system and a solid modeling software were utilized to calculate the joint positions of the participants as they walked barefooted on a level platform, walked barefooted on a 15° inversion platform, and walked with an ankle brace on a 15° inversion platform. The joint positions during the three walking conditions were compared.

RESULTS

Tibiotalar joints were more inverted (pose 2, p = .004), and subtalar joints were more anteriorly translated (pose 2-6, p = .003), more plantarflexed (pose 2, p = .008; pose 3, p = .013; pose 5, p = .008; pose 6, p = .016) and more inverted (pose 1-5, p = .003; pose 6, p = .013) during barefooted walking on the inversion platform than during walking on the level platform. The inversion of subtalar joints was decreased after the brace application (pose 2-4, p = .003; pose 5, p = .004; pose 7, p = .016).

SIGNIFICANCE

Brace application reduced the increased subtalar inversion induced by the inversion platform. Nevertheless, increased subtalar anterior translation and plantarflexion persisted after brace application. The ankle brace might be beneficial for clinical populations with increased subtalar inversion.

The Effects of Ankle Braces on Lower Extremity Electromyography and Performance During Vertical Jumping: A Pilot Study

Ankle braces have been hypothesized to prevent ankle injuries by restricting range of motion (ROM) and improving proprioception at the ankle. As such, ankle braces are commonly worn by physically active individuals to prevent ankle injuries. Despite their widespread use, the effects that ankle braces have on athletic performance measures, such as vertical jumping, remains unclear. Furthermore, although ankle braces are known to restrict normal ROM at the ankle, little is known about the effects that ankle braces have on the lower extremity proximal to the ankle, specifically muscular activation. Therefore, the purpose of this pilot study was to determine if lower extremity surface electromyographic activity (sEMG) and performance was affected in 5 males and 5 females by wearing softshell (AE) and semi-rigid (T1) ankle braces during a Vertical Jump Test, and to establish a basis for future investigation. Vertical jump height was not significantly affected (p > .05) in the AE (37.49 ± 11.61 cm) and T1 (36.3 ± 11.77 cm) ankle brace conditions, relative to the no brace (38.17 ± 12.01 cm) condition. No significant differences in sEMG of the lateral gastrocnemius and biceps femoris were present across conditions. There was a tendency for sEMG of the rectus femoris to decrease when wearing AE (195.71 ± 100.43 %MVC) and T1 (183.308 ± 92.73 %MVC) braces, compared to no braces (210.08 ± 127.46 %MVC), and warrants further investigation using a larger sample. Until more research is conducted, however, clinicians should not be concerned about ankle braces significantly affecting proximal muscle activation during vertical jumping.

The effects of instrument-assisted soft tissue mobilization on active range of motion, functional fitness, flexibility, and isokinetic strength in high school basketball players

Although many studies have focused on stretching techniques for athletes, no comprehensive studies have investigated the use of the instrument-assisted soft tissue mobilization (IASTM) technique in young basketball players. The active properties of muscle and subjective reporting of functional ability were used to identify the effects of IASTM on the calf muscle. Active range of motion (AROM), functional fitness, and isokinetic lower strength in the knees and ankles were measured in 40 healthy young basketball players. They were divided into the IASTM group (n= 20) and a control group (CG, n= 20). Twenty asymptomatic young basketball players were treated with IASTM six times per week for 8 weeks. The remaining 20 participants did not receive a treatment intervention between tests and served as the control. Ankle AROM (two knee positions of 0∘ and 45∘ flexion), functional fitness at the knee and ankle (side-step and vertical jump), and isokinetic peak torque were determined during ankle dorsiflexion (DF) and plantar flexion (PF) and knee extension (EX) and flexion (FX). The data were analyzed using repeated-measures analysis of variance. Significant differences were observed between the two groups in IASTM and control AROM 0∘ knee flexion (right: DF; p< 0.001 and PF; p< 0.001; left: DF; p< 0.001 and PF; p= 0.011), AROM 45∘ knee flexion (right: DF; p< 0.001 and PF; p= 0.009; left: DF; p< 0.001 and PF; p= 0.001), functional fitness (side step; p= 0.001, sit and reach; p= 0.025, vertical jump; p= 0.001), ankle isokinetic strength 30∘/sec (right: DF; p= 0.001 and PF; p= 0.001; left: DF; p< 0.001 and PF; p= 0.002), ankle isokinetic strength 120∘/sec (right: DF; p= 0.049 and PF; p= 0.001; left: DF; p= 0.023 and PF; p< 0.001), knee isokinetic strength 60∘/sec (right: EX; p= 0.001, FX; p= 0.001 and hamstring and quadriceps ratio [H/Q]; p= 0.001, left: EX; p= 0.001, FX; p= 0.001 and H/Q; p= 0.001), and knee isokinetic strength 180∘/sec (right: EX; p= 0.001, FX; p= 0.001 and H/Q; p= 0.001; left: EX; p= 0.001, FX; p= 0.010 and H/Q; p= 0.001). These results suggest that IASTM improves functional fitness and lower body muscle strength in young basketball players.

External ankle taping does not alter lower extremity side-step cut and straight sprint biomechanics in young adult males

Lateral ankle sprains (LAS) are one of the most common musculoskeletal injuries and as a response, clinicians often use external ankle taping prophylactically to reduce the prevalence of injuries. External ankle taping techniques have been shown to significantly reduce passive ankle range of motion; however, there is limited research on the effects of external ankle taping on lower extremity kinematics or kinetics during sport specific tasks. Therefore, our objective was to compare the effects of external ankle taping on ankle, knee and hip kinematics and kinetics compared to no taping during an anticipated sidestep cutting task and a straight sprint task. We conducted a cross-over laboratory study with 16 healthy males. Three-dimensional kinematics and kinetics were collected with a motion capture system and in-ground force plate during 5 trials of a sprint and anticipated side-step cut with or without external ankle taping. Group means and associated 90% confidence intervals were plotted across 100 data points for each task, significance being identified when the confidence intervals did not overlap for three consecutive data points. No significant kinetic or kinematic differences were identified between conditions for the tasks. External ankle taping does not influence lower extremity biomechanics during a control cutting task.

Effects of a semi-rigid ankle brace on ankle joint loading during landing on inclined surfaces

Ankle bracing is commonly used to prevent ankle sprain occurrences. The present study investigated the effects of a semi-rigid ankle brace on the ankle joint complex during landing on inclined surfaces. Seventeen recreational athletes performed a single leg landing task onto three different surface alignments (everted, neutral, inverted), with and without the brace. Ground reaction forces (GRF), kinematics, and brace pressure were recorded. Six two-way repeated measures MANOVA tested for differences in GRF, talocrural and subtalar kinematics and kinetics. Participants landed with a significantly less plantar flexed (P < 0.001) and more everted (P = 0.001) foot during the braced condition. Although no differences were observed for the joint moments, an increased subtalar compression force (P = 0.009) was observed with the brace. Landing on the inverted surface resulted in significantly higher peak magnitudes of the vertical and the mediolateral GRF and the talocrural inversion moment compared to landing on the neutral surface. Ankle bracing altered ankle kinematics by restricting the ROM of the ankle joint complex. This study confirmed that landing on inverted surfaces may increase the risk for lateral ankle ligaments injuries. The significantly higher subtalar compression force during the brace condition might contribute to overuse injuries.

Effect of prophylactic ankle taping on ankle and knee biomechanics during basketball-specific tasks in females

OBJECTIVE

The aim of this study was to investigate the effects of ankle taping on ankle and knee joint biomechanics during cutting and rebound activities in females.

DESIGN

Cross-sectional.

SETTING

Laboratory.

PARTICIPANTS

Twenty semi-professional female basketball players performed a cut and rebound task under two conditions (taped and no-tape).

MAIN OUTCOME MEASURES

Kinematic and ground reaction force data were collected during the deceleration phase of each movement task.

RESULTS

Taping resulted in a significant reduction in peak ankle dorsiflexion, inversion and internal rotation angles and range of motion (ROM) at the ankle joint; and reduced knee ROM in the sagittal plane during the rebound task only. Taping significantly reduced peak knee flexion moment (0.29 Nm/kg, P = 0.013) and increased knee internal rotation moment (0.63 Nm/kg, P = 0.026) during the cutting task compared to control. Taping also significantly reduced the internal rotation moment (0.07 Nm/kg, P = 0.025), and medial shear forces (0.14 N/kg, P = 0.012) in the rebound task.

CONCLUSION

Results of the study suggest that ankle taping restrict ankle range of movement in the rebound task only and ankle taping appears to have upstream effects on the knee, which may have injury implications.

Peak Lower Extremity Landing Kinematics in Dancers and Nondancers

CONTEXT

  Anterior cruciate ligament (ACL) injuries often occur during jump landings and can have detrimental short-term and long-term functional effects on quality of life. Despite frequently performing jump landings, dancers have lower incidence rates of ACL injury than other jump-landing athletes. Planned versus unplanned activities and footwear may explain differing ACL-injury rates among dancers and nondancers. Still, few researchers have compared landing biomechanics between dancers and nondancers.

OBJECTIVE

  To compare the landing biomechanics of dancers and nondancers during single-legged (SL) drop-vertical jumps.

DESIGN

  Cross-sectional study.

SETTING

  Laboratory.

PATIENTS OR OTHER PARTICIPANTS

  A total of 39 healthy participants, 12 female dancers (age = 20.9 ± 1.8 years, height = 166.4 ± 6.7 cm, mass = 63.2 ± 16.4 kg), 14 female nondancers (age = 20.2 ± 0.9 years, height = 168.9 ± 5.0 cm, mass = 61.6 ± 7.7 kg), and 13 male nondancers (age = 22.2 ± 2.7 years, height = 180.6 ± 9.7 cm, mass = 80.8 ± 13.2 kg).

INTERVENTION(S)

  Participants performed SL-drop-vertical jumps from a 30-cm-high box in a randomized order in 2 activity (planned, unplanned) and 2 footwear (shod, barefoot) conditions while a 3-dimensional system recorded landing biomechanics.

MAIN OUTCOME MEASURE(S)

  Overall peak sagittal-plane and frontal-plane ankle-, knee-, and hip-joint kinematics (joint angles) were compared across groups using separate multivariate analyses of variance followed by main-effects testing and pairwise-adjusted Bonferroni comparisons as appropriate ( P < .05).

RESULTS

  No 3-way interactions existed for sagittal-plane or frontal-plane ankle (Wilks λ = 0.85, P = .11 and Wilks λ = 0.96, P = .55, respectively), knee (Wilks λ = 1.00, P = .93 and Wilks λ = 0.94, P = .36, respectively), or hip (Wilks λ = 0.99, P = .88 and Wilks λ = 0.97, P = .62, respectively) kinematics. We observed no group × footwear interactions for sagittal-plane or frontal-plane ankle (Wilks λ = 0.94, P = .43 and Wilks λ = 0.96, P = .55, respectively), knee (Wilks λ = 0.97, P = .60 and Wilks λ = 0.97, P = .66, respectively), or hip (Wilks λ = 0.99, P = .91 and Wilks λ = 1.00, P = .93, respectively) kinematics, and no group × activity interactions were noted for ankle frontal-plane (Wilks λ = 0.92, P = .29) and sagittal- and frontal-plane knee (Wilks λ = 0.99, P = .81 and Wilks λ = 0.98, P = .77, respectively) and hip (Wilks λ = 0.88, P = .13 and Wilks λ = 0.85, P = .08, respectively) kinematics. A group × activity interaction (Wilks λ = 0.76, P = .02) was present for ankle sagittal-plane kinematics. Main-effects testing revealed different ankle frontal-plane angles across groups ( F_2,28 = 3.78, P = .04), with male nondancers having greater ankle inversion than female nondancers ( P = .05).

CONCLUSIONS

  Irrespective of activity type or footwear, female nondancers landed with similar hip and knee kinematics but greater peak ankle eversion and less peak ankle dorsiflexion (ie, positions associated with greater ACL injury risk). Ankle kinematics may differ between groups due to different landing strategies and training used by dancers. Dancers' training should be examined to determine if it results in a reduced occurrence of biomechanics related to ACL injury during SL landing.

The effects of ankle protectors on lower limb kinematics in male football players: a comparison to braced and unbraced ankles

Football (soccer) players have a high risk of injuring the lower extremities. To reduce the risk of ankle inversion injuries ankle braces can be worn. To reduce the risk of ankle contusion injuries ankle protectors can be utilised. However, athletes can only wear one of these devices at a time. The effects of ankle braces on stance limb kinematics has been extensively researched, however ankle protectors have had little attention. Therefore, the current study aimed to investigate the effects of ankle protectors on lower extremity kinematics during the stance phase of jogging and compare them with braced and uncovered ankles. Twelve male participants ran at 3.4 m/s in three test conditions; ankle braces (BRACE), ankle protectors (PROTECTOR) and with uncovered ankles (WITHOUT). Stance phase kinematics were collected using an eight-camera motion capture system. Kinematic data between conditions were analysed using one-way repeated measures ANOVA. The results showed that BRACE (absolute range of motion (ROM) = 10.72° and relative ROM = 10.26°) significantly (P<0.05) restricted the ankle in the coronal plane when compared to PROTECTOR (absolute ROM=13.44° and relative ROM =12.82°) and WITHOUT (absolute ROM=13.64° and relative ROM=13.10°). It was also found that both BRACE (peak dorsiflexion=17.02° and absolute ROM=38.34°) and PROTECTOR (peak dorsiflexion =18.46° and absolute ROM =40.15°) significantly (P<0.05) reduced sagittal plane motion when compared to WITHOUT (peak dorsiflexion =19.20° and absolute ROM =42.66°). Ankle protectors’ effects on lower limb kinematics closely resemble that of an unbraced ankle. Therefore, ankle protectors should only be used as a means to reduce risk of ankle contusion injuries and not implemented as a method to reduce the risk of ankle inversion injuries. Furthermore, the reductions found in sagittal plane motion of the ankle could possibly increase the bodies energy demand needed for locomotion when ankle protectors are utilised.

The effects of ankle braces and taping on lower extremity running kinematics and energy expenditure in healthy, non-injured adults

Ankle braces and taping are commonly used to prevent ankle sprains and allow return to play following injury, however, it is unclear how passive restriction of joint motion may effect running gait kinematics and energy expenditure during exercise. The purpose of this study was to determine the effect of different types of ankle supports on lower extremity kinematics and energy expenditure during continuous running. Thirteen healthy physically active adults ran at self-selected speed on the treadmill for 30min in four different ankle support conditions: semi-rigid hinged brace, lace-up brace, tape and control. Three-dimensional lower extremity kinematics and energy expenditure were recorded every five minutes. The semi-rigid hinged brace was most effective in restricting frontal plane ankle motion. The lace-up brace and tape restricted sagittal plane ankle motion, while semi-rigid hinged bracing allowed for normal sagittal plane ankle kinematics. Kinematic changes from all three ankle supports were generally persistent through 25-30min of exercise. Only tape influenced knee kinematics, limiting flexion velocity and flexion-extension excursion. Small but significant increased in energy expenditure was found in tape and semi-rigid hinged brace conditions; however, the increases were not to any practically significant level (<0.5kcal/min).

Ankle brace attenuates the medial-lateral ground reaction force during basketball rebound jump

ABSTRACT Introduction: The jump landing is the leading cause for ankle injuries in basketball. It has been shown that the use of ankle brace is effective to prevent these injuries by increasing the mechanical stability of the ankle at the initial contact of the foot with the ground. Objective: To investigate the effects of ankle brace on the ground reaction force (GRF) during the simulation of a basketball rebound jump. Method: Eleven young male basketball players randomly carried out a simulated basketball rebound jump under two conditions, with and without ankle brace (lace-up). Dynamic parameters of vertical GRF (take-off and landing vertical peaks, time to take-off and landing vertical peaks, take-off impulse peak, impulse at 50 milliseconds of landing, and jump height) and medial-lateral (take-off and landing medial-lateral peaks, and time to reach medial-lateral peaks at take-off and landing) were recorded by force platform during rebound jumps in each tested condition. The comparisons between the tested conditions were performed by paired t test (P<0.05). Results: The use of ankle braces reduced the medial and lateral peaks of the GRF by -15.7% (P=0.035) and -24.9% (P=0.012), respectively, during the landing of the rebound jump. Additionally, wearing the brace did not affect any dynamic parameters of vertical GRF or temporal parameters of the medial-lateral GRF (P>0.05). Conclusion: The use of ankle brace during basketball rebound jumps attenuates the magnitude of medial-lateral GRF on the landing phase, without changing the vertical GRF. This finding indicates that the use of brace increases the medial-lateral mechanical protection by decreasing the shear force exerted on the athlete’s body without change the application of propulsive forces in the take-off and the impact absorption quality in the landing during the basketball rebound jump.

Effect of External Ankle Support on Ankle and Knee Biomechanics During the Cutting Maneuver in Basketball Players

BACKGROUND

Despite the high prevalence of lower extremity injuries in female basketball players as well as a high proportion of athletes who wear ankle braces, there is a paucity of research pertaining to the effects of ankle bracing on ankle and knee biomechanics during basketball-specific tasks.

PURPOSE

To compare the effects of a lace-up brace (ASO), a hinged brace (Active T2), and no ankle bracing (control) on ankle and knee joint kinematics and joint reaction forces in female basketball athletes during a cutting maneuver.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty healthy, semi-elite female basketball players performed a cutting task under both ankle brace conditions (lace-up ankle brace and hinged ankle brace) and a no-brace condition. The 3-dimensional kinematics of the ankle and knee during the cutting maneuver were measured with an 18-camera motion analysis system (250 Hz), and ground-reaction force data were collected by use of a multichannel force plate (2000 Hz) to quantify ankle and knee joint reaction forces. Conditions were randomized using a block randomization method.

RESULTS

Compared with the control condition, the hinged ankle brace significantly restricted peak ankle inversion (mean difference, 1.7°; P = .023). No significant difference was found between the lace-up brace and the control condition ( P = .865). Compared with the lace-up brace, the hinged brace significantly reduced ankle and knee joint compressive forces at the time of peak ankle dorsiflexion (mean difference, 1.5 N/kg [ P = .018] and 1.4 N/kg [ P = .013], respectively). Additionally, the hinged ankle brace significantly reduced knee anterior shear forces compared with the lace-up brace both during the deceleration phase and at peak ankle dorsiflexion (mean difference, 0.8 N/kg [ P = .018] and 0.9 N/kg [ P = .011], respectively).

CONCLUSION

The hinged ankle brace significantly reduced ankle inversion compared with the no-brace condition and reduced ankle and knee joint forces compared with the lace-up brace in a female basketball population during a cutting task. Compared with the lace-up brace, the hinged brace may be a better choice of prophylactic ankle support for female basketball players from a biomechanical perspective. However, both braces increased knee internal rotation and knee abduction angles, which may be problematic for a population that already has a high prevalence of knee injuries.

Effects of Prophylactic Ankle Supports on Vertical Ground Reaction Force During Landing: A Meta-Analysis

There has been much debate on how prophylactic ankle supports (PASs) may influence the vertical ground reaction force (vGRF) during landing. Therefore, the primary aims of this meta-analysis were to systematically review and synthesize the effect of PASs on vGRF, and to understand how PASs affect vGRF peaks (F1, F2) and the time from initial contact to peak loading (T1, T2) during landing. Several key databases, including Scopus, Cochrane, Embase, PubMed, ProQuest, Medline, Ovid, Web of Science, and the Physical Activity Index, were used for identifying relevant studies published in English since inception to April 1, 2015. The computerized literature search and cross-referencing the citation list of the articles yielded 3,993 articles. Criteria for inclusion required that 1) the study was conducted on healthy adults; 2) the subject number and trial number were known; 3) the subjects performed landing with and without PAS; 4) the landing movement was in the sagittal plane; 5) the comparable vGRF parameters were reported; and 6) the F1 and F2 must be normalized to the subject's body weight. After the removal of duplicates and irrelevant articles, 6, 6, 15 and 11 studies were respectively pooled for outcomes of F1, T1, F2 and T2. This study found a significantly increased F2 (.03 BW, 95% CI: .001, .05) and decreased T1 (-1.24 ms, 95% CI: -1.77, -.71) and T2 (-3.74 ms, 95% CI: -4.83, -2.65) with the use of a PAS. F1 was not significantly influenced by the PAS. Heterogeneity was present in some results, but there was no evidence of publication bias for any outcome. These changes represented deterioration in the buffering characteristics of the joint. An ideal PAS design should limit the excessive joint motion of ankle inversion, while allowing a normal range of motion, especially in the sagittal plane. Key pointsPAS can effectively protect the ligamentous structure from spraining by providing mechanical support and cutaneous proprioceptive benefits.Using of PAS can significantly elevate F2 and reduce T1 and T2 during landing. These changes represented deterioration in the buffering characteristics of the joint.An ideal PAS design should limit the excessive joint motion of the ankle inversion, while allow normal range of motion, especially in the sagittal plane.

The effect of ankle bracing on landing biomechanics in female netballers

OBJECTIVES

Investigate the impact of lace-up ankle braces on landing biomechanics.

DESIGN

Within-subject repeated measures. Participants completed a drop jump, drop land, and netball-specific task in braced and unbraced conditions.

SETTING

Biomechanical research laboratory.

PARTICIPANTS

Twenty female high school netballers.

MAIN OUTCOME MEASURES

Leg, knee, and ankle stiffness, knee/ankle stiffness ratio, knee and ankle sagittal excursion, peak vertical ground reaction force, time-to-peak vertical ground reaction force, and loading rate.

RESULTS

In the brace condition leg stiffness increased bilaterally during the drop land (ES = 0.21, 0.22), ankle stiffness increased bilaterally during the drop jump (ES = 0.37, 0.29) and drop land (ES = 0.40, 0.60), and knee/ankle stiffness ratio decreased in all three tasks (ES = -0.22 to -0.45). Ankle sagittal excursion decreased bilaterally during the drop jump (ES = -0.35, -0.53) and drop land (ES = -0.23, -0.46), and decreased in the lead limb during the netball jump (ES = -0.36). Knee excursion decreased bilaterally during the drop jump (ES = -0.36, -0.40) and in the lead limb during netball task (ES = -0.59). Lead limb TTP was greater during the netball jump (ES = 0.41).

CONCLUSIONS

Lace-up ankle braces may increase leg and joint stiffness and reduce joint excursion during landing but do not appear to affect landing forces. The observed effect on landing biomechanics may predispose young netballers to injury.

Effect of kinesiotaping, non-elastic taping and bracing on segmental foot kinematics during drop landing in healthy subjects and subjects with chronic ankle instability

OBJECTIVE

To evaluate the effects of kinesiotape, non-elastic tape, and soft brace on segmental foot kinematics during drop landing in subjects with chronic ankle instability and healthy subjects.

DESIGN

Controlled study with repeated measurements.

SETTING

Three-dimensional motion analysis laboratory.

PARTICIPANTS

Twenty participants with chronic ankle instability and 20 healthy subjects.

INTERVENTIONS

The subjects performed drop landings with 17 retroreflective markers on the foot and lower leg in four conditions: barefoot, with kinesiotape, with non-elastic tape and with a soft brace.

MAIN OUTCOME MEASURES

Ranges of motion of foot segments using a foot measurement method.

RESULTS

In participants with chronic ankle instability, midfoot movement in the frontal plane (inclination of the medial arch) was reduced significantly by non-elastic taping, but kinesiotaping and bracing had no effect. In healthy subjects, both non-elastic taping and bracing reduced that movement. In both groups, non-elastic taping and bracing reduced rearfoot excursion in inversion/eversion significantly, which indicates a stabilisation effect. No such effect was found with kinesiotaping. All three methods reduced maximum plantar flexion significantly.

CONCLUSIONS

Non-elastic taping stabilised the midfoot best in patients with chronic ankle instability, while kinesiotaping did not influence foot kinematics other than to stabilise the rearfoot in the sagittal plane.

CLINICAL TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT01810471.

The effect of ankle bracing on lower extremity biomechanics during landing: A systematic review

OBJECTIVES

To examine the evidence for effect of ankle bracing on lower-extremity landing biomechanics.

DESIGN

Literature review.

METHODS

Systematic search of the literature on EBSCO health databases. Articles critiqued by two reviewers.

RESULTS

Ten studies were identified which investigated the effect of ankle bracing on landing biomechanics. Overall results suggest that landing biomechanics are altered with some brace types but studies disagree as to the particular variables affected.

CONCLUSIONS

There is evidence that ankle bracing may alter lower-extremity landing biomechanics in a manner which predisposes athletes to injury. The focus of studies on specific biomechanical variables rather than biomechanical patterns, analysis of pooled data means in the presence of differing landing styles between participants, variation in landing-tasks investigated in different studies, and lack of studies investigating goal-directed sport-specific landing tasks creates difficulty in interpreting results. These areas require further research.

Altered knee and ankle kinematics during squatting in those with limited weight-bearing-lunge ankle-dorsiflexion range of motion

CONTEXT

Ankle-dorsiflexion (DF) range of motion (ROM) may influence movement variables that are known to affect anterior cruciate ligament loading, such as knee valgus and knee flexion. To our knowledge, researchers have not studied individuals with limited or normal ankle DF-ROM to investigate the relationship between those factors and the lower extremity movement patterns associated with anterior cruciate ligament injury.

OBJECTIVE

To determine, using 2 different measurement techniques, whether knee- and ankle-joint kinematics differ between participants with limited and normal ankle DF-ROM.

DESIGN

Cross-sectional study.

SETTING

Sports medicine research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Forty physically active adults (20 with limited ankle DF-ROM, 20 with normal ankle DF-ROM).

MAIN OUTCOME MEASURE(S)

Ankle DF-ROM was assessed using 2 techniques: (1) nonweight-bearing ankle DF-ROM with the knee straight, and (2) weight-bearing lunge (WBL). Knee flexion, knee valgus-varus, knee internal-external rotation, and ankle DF displacements were assessed during the overhead-squat, single-legged squat, and jump-landing tasks. Separate 1-way analyses of variance were performed to determine whether differences in knee- and ankle-joint kinematics existed between the normal and limited groups for each assessment.

RESULTS

We observed no differences between the normal and limited groups when classifying groups based on nonweight-bearing passive-ankle DF-ROM. However, individuals with greater ankle DF-ROM during the WBL displayed greater knee-flexion and ankle-DF displacement and peak knee flexion during the overhead-squat and single-legged squat tasks. In addition, those individuals also demonstrated greater knee-varus displacement during the single-legged squat.

CONCLUSIONS

Greater ankle DF-ROM assessed during the WBL was associated with greater knee-flexion and ankle-DF displacement during both squatting tasks as well as greater knee-varus displacement during the single-legged squat. Assessment of ankle DF-ROM using the WBL provided important insight into compensatory movement patterns during squatting, whereas nonweight-bearing passive ankle DF-ROM did not. Improving ankle DF-ROM during the WBL may be an important intervention for altering high-risk movement patterns commonly associated with noncontact anterior cruciate ligament injury.

Weight-Bearing Dorsiflexion Range of Motion and Landing Biomechanics in Individuals With Chronic Ankle Instability

CONTEXT

People with chronic ankle instability (CAI) exhibit less weight-bearing dorsiflexion range of motion (ROM) and less knee flexion during landing than people with stable ankles. Examining the relationship between dorsiflexion ROM and landing biomechanics may identify a modifiable factor associated with altered kinematics and kinetics during landing tasks.

OBJECTIVE

To examine the relationship between weight-bearing dorsiflexion ROM and single-legged landing biomechanics in persons with CAI.

DESIGN

Cross-sectional study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Fifteen physically active persons with CAI (5 men, 10 women; age = 21.9 ± 2.1 years, height = 168.7 ± 9.0 cm, mass = 69.4 ± 13.3 kg) participated.

INTERVENTION(S)

Participants performed dorsiflexion ROM and single-legged landings from a 40-cm height. Sagittal-plane kinematics of the lower extremity and ground reaction forces (GRFs) were captured during landing.

MAIN OUTCOME MEASURE(S)

Static dorsiflexion was measured using the weight-bearing-lunge test. Kinematics of the ankle, knee, and hip were observed at initial contact, maximum angle, and sagittal displacement. Sagittal displacements of the ankle, knee, and hip were summed to examine overall sagittal displacement. Kinetic variables were maximum posterior and vertical GRFs normalized to body weight. We used Pearson product moment correlations to evaluate the relationships between dorsiflexion ROM and landing biomechanics. Correlations (r) were interpreted as weak (0.00-0.40), moderate (0.41-0.69), or strong (0.70-1.00). The coefficient of determination (r(2)) was used to determine the amount of explained variance among variables.

RESULTS

Static dorsiflexion ROM was moderately correlated with maximum dorsiflexion (r = 0.49, r(2) = 0.24), ankle displacement (r = 0.47, r(2) = 0.22), and total displacement (r = 0.67, r(2) = 0.45) during landing. Dorsiflexion ROM measured statically and during landing demonstrated moderate to strong correlations with maximum knee (r = 0.69-0.74, r(2) = 0.47-0.55) and hip (r = 0.50-0.64, r(2) = 0.25-0.40) flexion, hip (r = 0.53-0.55, r(2) = 0.28-0.30) and knee (r = 0.53-0.70, r(2) = 0.28-0.49) displacement, and vertical GRF (-0.47- -0.50, r(2) = 0.22-0.25).

CONCLUSIONS

Dorsiflexion ROM was moderately to strongly related to sagittal-plane kinematics and maximum vertical GRF during single-legged landing in persons with CAI. Persons with less dorsiflexion ROM demonstrated a more erect landing posture and greater GRF.

Effect of ankle braces on lower extremity muscle activation during functional exercises in participants with chronic ankle instability

BACKGROUND

Ankle bracing and rehabilitation are common methods to reduce the rate of recurrent ankle sprain in participants with chronic ankle instability (CAI). CAI participants utilize less muscle activity when performing functional exercises compared to healthy controls. The effect of ankle braces on muscle activity during functional exercises in participants with CAI has not been previously studied.

PURPOSE

To determine the effect of bracing on motor output as demonstrated by surface EMG amplitudes in participants with CAI during single limb, eyes closed balance, star excursion balance, forward lunge, and lateral hop exercises.

METHODS

A descriptive laboratory study was performed. Fifteen young adults with CAI performed functional exercises with and without ankle braces while surface EMG signals were recorded from the tibialis anterior, peroneus longus, lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius. The main outcome measures were normalized surface EMG amplitudes (root mean square area) for each muscle, muscles of the shank (distal three muscles), muscles of the thigh (proximal three muscles), and total muscle activity (all six muscles) of the lower extremity. A paired t-test was performed for each dependent variable to compare conditions. The level of significance was set a priori at p ≤ 0.05 for all analyses.

RESULTS

During the forward lunge, bracing significantly reduced muscle activity pre-initial contact in the lateral gastrocnemius and post-initial contact in the peroneus longus. During the star excursion balance anterior reach the peroneus longus, lateral gastrocnemius, rectus femoris, and gluteus medius had significantly less muscle activity during braced trials. Bracing significantly reduced thigh and total muscle activity during the anterior reach and gluteus medius activity during the posterolateral reach. There were no differences between braced and unbraced conditions during the single limb eyes closed balance, star excursion balance posteromedial reach, or during lateral hop exercises.

CONCLUSIONS

Clinicians should be aware of the decreased muscle activity that occurs during common rehabilitation exercises when patients with CAI complete those activities while wearing ankle braces.

LEVEL OF EVIDENCE

Level III.

Gait kinematics after taping in participants with chronic ankle instability

CONTEXT

Chronic ankle instability is characterized by repetitive lateral ankle sprains. Prophylactic ankle taping is a common intervention used to reduce the risk of ankle sprains. However, little research has been conducted to evaluate the effect ankle taping has on gait kinematics.

OBJECTIVE

To investigate the effect of taping on ankle and knee kinematics during walking and jogging in participants with chronic ankle instability.

DESIGN

Controlled laboratory study.

SETTING

Motion analysis laboratory.

PATIENTS OR PARTICIPANTS

A total of 15 individuals (8 men, 7 women; age = 26.9 ± 6.8 years, height = 171.7 ± 6.3 cm, mass = 73.5 ± 10.7 kg) with self-reported chronic ankle instability volunteered. They had an average of 5.3 ± 3.1 incidences of ankle sprain.

INTERVENTION(S)

Participants walked and jogged in shoes on a treadmill while untaped and taped. The tape technique was a traditional preventive taping procedure. Conditions were randomized.

MAIN OUTCOME MEASURE(S)

Frontal-plane and sagittal-plane ankle and sagittal-plane knee kinematics were recorded throughout the entire gait cycle. Group means and 90% confidence intervals were calculated, plotted, and inspected for percentages of the gait cycle in which the confidence intervals did not overlap.

RESULTS

During walking, participants were less plantar flexed from 64% to 69% of the gait cycle (mean difference = 5.73° ± 0.54°) and less inverted from 51% to 61% (mean difference = 4.34° ± 0.65°) and 76% to 81% (mean difference = 5.55° ± 0.54°) of the gait cycle when taped. During jogging, participants were less dorsiflexed from 12% to 21% (mean difference = 4.91° ± 0.18°) and less inverted from 47% to 58% (mean difference = 6.52° ± 0.12°) of the gait cycle when taped. No sagittal-plane knee kinematic differences were found.

CONCLUSIONS

In those with chronic ankle instability, taping resulted in a more neutral ankle position during walking and jogging in shoes on a treadmill. This change in foot positioning and the mechanical properties of the tape may explain the protective aspect of taping in preventing lateral ankle sprains.

Asymmetrical loading demands associated with vertical jump landings in people with unilateral transtibial amputation

Loading symmetry during vertical jump landings between a person with amputation's intact and prosthetic limbs was assessed to determine the role of each limb in controlling the downward momentum of the center of mass during landing. Six participants with unilateral transtibial amputation (TTA) and ten nondisabled participants completed 10 maximal vertical jumps, of which the highest jump was analyzed. Contralateral symmetry was assessed through the Symmetry Index (SI), while symmetry at the group level was assessed through a Mann-Whitney U test. Participants with TTA performed quasi-unilateral landings onto the intact limbs, resulting from either the incapability of the prosthetic ankle to plantar flex or increased residual-limb knee and hip flexion. In the loading phase, the participants with TTA displayed reduced prosthetic-side peak vertical forces (p = 0.04) along with reduced prosthetic-side ankle range of motion (p < 0.001), extensor moments (p = 0.03), and negative work generated (p = 0.00). Individual asymmetries were evident in the peak vertical force magnitudes (SI = 51%-140%), duration from touchdown to peak vertical force (SI = 52%-157%), ankle joint angles at touchdown (SI = 100%-538%), ranges of motion (SI = 147%-200%), knee (SI = 66%-179%) and hip (SI = 87%-132%) extensor moments, and work done at the ankle (SI = 155%-199%) and hip (SI = 83%-204%). High peak forces (25.25 +/- 4.89 N·kg(-1) intact limb and 14.61 +/- 8.28 N·kg(-1) prosthetic limb) from significantly lower (p < 0.001) landing heights than the nondisabled participants indicate a potential injury risk associated with landing for people with TTA.

Effect of lace-up ankle braces on electromyography measures during walking in adults with chronic ankle instability

BACKGROUND

Lace-up ankle braces reduce the incidence of ankle sprains and have been hypothesized to do so through both mechanical and neuromuscular mechanisms.

OBJECTIVE

To determine the effect of lace-up ankle braces on surface electromyography (sEMG) measures during walking in adults with chronic ankle instability (CAI).

DESIGN

Randomized crossover.

SETTING

Laboratory.

PARTICIPANTS

Fifteen adults with CAI.

MAIN OUTCOME MEASURES

Surface EMG activity was recorded from the anterior tibialis, peroneus longus, lateral gastrocnemius, rectus femoris, biceps femoris and gluteus medius during treadmill walking with and without lace-up ankle braces. The dependent variables were sEMG amplitude 100 ms pre- and 200 ms post-initial contact, time of activation relative to initial contact, and percent of activation across the stride cycle.

RESULTS

When compared to no brace, ankle bracing resulted in lower pre-contact amplitude of the peroneus longus (p = 0.02). The anterior tibialis, peroneus longus, rectus femoris, and gluteus medius were activated later relative to initial contact (p < 0.03). The peroneus longus and rectus femoris were activated for a shorter percentage of the stride cycle (p < 0.05).

CONCLUSION

Braces cause a change in neuromuscular activity during walking. Clinicians should be aware of these changes when prescribing braces, as it may relate to the mechanism in which braces decrease sprains.

Basketball coaches' utilization of ankle injury prevention strategies

BACKGROUND

Ankle injuries are the most common high school basketball injury. Little is known regarding the utilization of ankle injury prevention strategies in high school settings.

OBJECTIVE

To determine high school basketball coaches' utilization of ankle injury prevention strategies, including prophylactic ankle bracing (PAB) or an ankle injury prevention exercise program (AIEPP).

STUDY DESIGN

Cross-sectional survey.

METHODS

The survey was distributed to all high school basketball coaches in Wisconsin. Fisher exact and Wilcoxon rank sum tests were used to determine if the injury prevention strategies utilized differed according to school size, sex of the team, years of coaching experience, and the coach's education level.

RESULTS

Four hundred eighty (55%) coaches from 299 (74%) high schools completed the survey. Thirty-seven percent of the coaches encouraged or required their players to use PAB. School enrollment of the coaches' teams did not affect their stance on the use of PAB (P = 0.30), neither did the sex of the team (P = 0.16), years coaching (P = 0.09), nor the coach's education (P = 0.49). Fifty percent (n = 242) of the coaches indicated they do not utilize an AIEPP, with no difference based on school enrollment (P = 0.47), team sex (P = 0.41), years coaching (P = 0.78), or the education level (P = 0.44). Barriers to utilization of AIEPP included a lack of time, awareness, and expertise. Coaches preferred an AIEPP that was specific to basketball, combined injury prevention and performance enhancement components, was performed 2 to 3 days per week, and lasted 5 to 15 minutes.

CONCLUSION

Less than half of the coaches encouraged use of PAB, and half did not utilize an AIEPP. Coaches had specific preferences for the type of AIEPP they would implement.

CLINICAL RELEVANCE

Sports medicine providers should promote ankle injury prevention strategies but need to address why prevention strategies may not be utilized in high school basketball settings.

Does Wearing a Prophylactic Ankle Brace During Drop Landings Affect Lower Extremity Kinematics and Ground Reaction Forces?

The objective of the study was to determine if prophylactic ankle bracing worn by females during landings produces abnormal lower extremity mechanics. Angular kinematic and ground reaction force (GRF) data were obtained for 16 athletically experienced females who performed brace and no-brace drop landings. The brace condition displayed reduced in/external rotation and flexion displacements about the ankle and knee joints and increased vertical and mediolateral GRF peak magnitudes and rate of vertical GRF application (pairedttest,P< .05). The ankle and knee joints landed in a less plantar flexed and more flexed position, respectively. No significant ab/adduction outcomes may have occurred due to interparticipant variability and/or a lack of brace restriction. Conclusion: During typical landings, this lace-up brace increases vertical GRF, decreases ankle and knee joint displacements of flexion and int/external rotation, but minimally affects ab/adduction displacements.

The influence of heel height on vertical ground reaction force during landing tasks in recreationally active and athletic collegiate females

PURPOSE

To determine if heel height alters vertical ground reaction forces (vGRF) when landing from a forward hop or drop landing.

BACKGROUND

Increased vGRF during landing are theorized to increase ACL injury risk in female athletes.

METHODS

Fifty collegiate females performed two single-limb landing tasks while wearing heel lifts of three different sizes (0, 12 & 24 mm) attached to the bottom of a athletic shoe. Using a force plate, peak vGRF at landing was examined. Repeated measures ANOVAs were used to determine the influence of heel height on the dependent measures.

RESULTS

Forward hop task- Peak vGRF (normalized for body mass) with 0 mm, 12 mm, and 24 mm lifts were 2.613±0.498, 2.616±0.497 and 2.495±0.518% BW, respectively. Significant differences were noted between 0 and 24 mm lift (p<.001) and 12 and 24 mm lifts (p=.004), but not between the 0 and 12 mm conditions (p=.927). Jump-landing task- No significant differences were found in peak vGRF (p=.192) between any of the heel lift conditions.

CONCLUSIONS

The addition of a 24 mm heel lift to the bottom of a sneaker significantly alters peak vGRF upon landing from a unilateral forward hop but not from a jumping maneuver.

The effect of lace-up ankle braces on injury rates in high school football players

BACKGROUND

Although ankle injuries occur frequently in high school football players, no prospective studies have been performed to determine if wearing lace-up ankle braces will reduce the incidence and severity of ankle and other lower extremity injuries in these athletes.

PURPOSE

This study was conducted to determine if lace-up ankle braces reduce the incidence and severity of lower extremity injuries sustained by high school football players.

DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 2081 players from 50 high schools were randomly assigned to a braced or control group. Braced group players wore lace-up ankle braces during the 2010 football season. Athletic trainers recorded brace compliance, athlete-exposures, and injuries. Cox proportional hazards models were utilized to compare injury rates between groups. Injury severity (days lost) was tested with Wilcoxon rank sum.

RESULTS

The rate of acute ankle injury (per 1000 exposures) was 0.48 in the braced group compared with 1.12 in the control group (Cox hazard ratio [HR] = 0.39; 95% confidence interval [CI], 0.24-0.65; P < .001). The severity (median days lost) of acute ankle injuries was the same (5 days) in both groups (P = .985). The rate of acute knee injury was 0.70 in the braced group compared with 0.69 in the control group (HR = 0.92; 95% CI, 0.57-1.47; P = .721). There was no difference (P = .242) in the severity of knee injuries between the groups (controls = 11.5 days, braced = 17 days). The rate of other lower extremity injuries was 0.95 in the braced group and 1.32 in the control group (HR = 0.72; 95% CI, 0.48-1.09; P = .117), while the severity was similar in both groups (6 days vs 7 days; P = .295).

CONCLUSION

Players who used lace-up ankle braces had a lower incidence of acute ankle injuries but no difference in the incidence of acute knee or other lower extremity injuries. Braces did not reduce the severity of ankle, knee, or other lower extremity injuries.