Factors contributing to ankle instability

Chronic ankle instability, repetitive giving way of the ankle, commonly develops from an initial ankle sprain. Our purpose was to identify factors contributing to ankle sprain, and whether or not kinematic, kinetic, and surface electromyography differences existed between mechanically unstable (MAI), functionally unstable (FAI), and comparison groups of subjects performing five different tasks (walking, stepping up and over, running, drop jumping, and stop jumping). There were 11 male and 10 female subjects in each of the three groups, matched by gender, age, height, mass, and limb dominance. An electromagnetic tracking system, coupled with a forceplate and telemetered surface electromyography were used to collect data. Unstable ankle subjects reported repeated episodes of spraining, and MAI subjects displayed positive anterior drawer and/or talar tilt tests. Using estimates of adjusted means, 95% confidence intervals, and effect sizes, we noted the MAI group displayed a pattern across tasks of increased dorsiflexion and eversion, increased frontal plane displacement and decreased sagittal plane displacement, with slower time to peak anterior ground reaction force in comparison with the FAI and comparison group. The FAI group demonstrated increased tibialis anterior mean amplitude as a percentage of maximum voluntary isometric contraction, but decreased lateral gastrocnemius mean amplitude. The coefficient of variation and standard deviation (SD) were obtained from an ensemble curve of each variable from the 8 test trials. The unstable groups displayed greater loge SD in the ankle inversion-eversion motion than the comparison group. The MAI group demonstrated smaller SD values for each the tibialis anterior, peroneals, and lateral gastrocnemius in comparison to the FAI group. The altered movement pattern may be a coping mechanism designed to keep the ankle in a stable position, perhaps by relying on bony stability and not stressing the anterior talofibular ligament. The increased variability observed in the unstable groups may predispose them to experience "risky" joint positions, closer to the limits of injury, and the FAI group may not activate their leg muscles enough to sufficiently rely on the muscles as dynamic stabilizers. These findings provide an explanation for the pathomechanics of ankle instability and need to be considered in rehabilitation programs

Comparison Between Single and Combined Clinical Postural Stability Tests in Individuals With and Without Chronic Ankle Instability

Objective: To determine if a single or/and combined clinical tests match group membership based on self-reported ankle function. Design: Cross-sectional. Setting: Biomechanics Laboratory. Participants: From participants, 58 meeting inclusion/exclusion criteria were divided into a chronic ankle instability (CAI) group (n = 25) who reported ≤25 on the Cumberland Ankle Instability Tool (CAIT) and a history of moderate–severe ankle sprain(s) and a control group (n = 33) who reported ≥29 on the CAIT and no history of ankle sprain(s). Interventions: Participants completed the following clinical tests: Foot Lift Test (FLT), the Star Excursion Balance Test (SEBT), the Single-Leg Hop Test (SLHT), and the Time in Balance Test (TIB) in a randomized order. A linear regression model was applied to determine measures that matched ankle group membership. Main Outcome Measures: The mean of SEBT reach distance was normalized to percentage leg length. The mean of number of errors in the FLT was recorded. The SLHT and TIB were reported as time in seconds, and the means were calculated. Results: The most parsimonious combination of tests (SLHT and SEBT) resulted in correctly matching 70.69% (41/58) of participants into groups, which was significantly better than chance. The multiple correlation coefficients (R value) for combining the SLHT and SEBT was 0.39. Conclusions: Using SLHT and SEBT resulted in improved recognition of participants designated into the CAI or control groups. Self-report perception of ankle function provides limited information for clinicians and researchers. Using multiple clinical function tests may be more helpful in determining deficits and intervention effectiveness

The relationship between acute pain and dynamic postural stability indices in individuals with patellar tendinopathy

Background Patellar tendinopathy is a common condition resulting in persistent pain, frequently reported during physical activity. The relationship between dynamic postural stability and pain in these individuals is unclear and how it may affect postural stability. Research Question Is there a relationship between acute pain and dynamic postural stability indices in individuals with patellar tendinopathy? Methods Twenty-two recreationally active individuals with patellar tendinopathy participated. Participants performed a two-legged jump and landed on a single test-limb on a force platform. They completed 100 mm visual analogue scales (VAS) before and after landing trials. Anterior-posterior (APSI), medial-lateral (MLSI), vertical (VSI), and composite (DPSI) stability indices were calculated from ground reaction force data. The relationship between stability indices and VAS for pain as well as pain change scores were assessed via non-parametric Spearman’s rho (ρ) rank correlations (p≤.05). Results Baseline pain was not significantly correlated with any stability indices. Post-landing pain was significantly correlated with MLSI (ρ = 0.540, p = 0.004) while, VSI (ρ = 0.353, p = 0.053) and DPSI (ρ = 0.347, p = 0.057) had moderate, yet insignificant correlations. Pain change scores demonstrated a large correlation with MLSI (ρ = 0.598, p = 0.002). Significance As pain increased in individuals with patellar tendinopathy, dynamic postural stability indices values increased, indicating more difficulty transitioning from a dynamic to static state. Although balance deficits are not typically associated with patellar tendinopathy, it appears pain and dynamic postural stability may be related in these individuals

Single-limb landing biomechanics are altered and patellar tendinopathy related pain is reduced with acute infrapatellar strap application

Background Patellar tendinopathy, a common condition of the knee, is often treated with patellar tendon straps to control pain during dynamic activity. Little is known regarding their effect on pain, landing kinematics and kinetics with their application. The purpose of this study was to determine if patellar tendon straps influenced pain, kinematics at landing and ground reaction forces in individuals with patellar tendinopathy versus healthy controls. Methods Thirty participants with patellar tendinopathy and 30 controls participated. They completed single-limb landings with and without patellar tendon straps while pain, three-dimensional kinematics and vertical ground reaction forces were measured. A multivariate analysis of variance was completed to determine the differences in strapping condition and group for the dependent variables. Results Individuals with patellar tendinopathy demonstrated a significant decrease in pain (no strap = 37.1 ± 22.1 mm (mean ± SD), strap = 28.0 ± 18.5 mm (mean ± SD)). With the strap at landing all participants displayed less hip rotation (F = 7.16, p = .01), knee adduction (F = 10.20, p = .002), ankle inversion (F = 4.60, p = .04), and peak vertical ground reaction force (F = 7.30, p = .009). Conclusions Patellar tendon straps reduced pain in those with patellar tendinopathy. Additionally, with the strap, individuals landed in a more neutral alignment and decreased landing forces which could provide a benefit to those with patellar tendinopathy

Functional performance deficits in adolescent athletes with a history of lateral ankle sprain(s)

Objective To determine if adolescent athletes with a history of lateral ankle sprain(s) (LAS) displayed deficits on functional performance tests (FPTs) and if deficits on FPT were related to the number of previous LAS. Design Cross-sectional study. Setting Biomechanics Laboratory. Participants The injured group (n = 24) had a history of ≥1 moderate-severe LAS. The uninjured group (n = 34) had no history of LAS. Main outcome measure(s) The average reach distance of three trials in each direction of the star excursion balance test (SEBT) was normalized to leg length (%). The average of two trials of single-leg-hop test (SLHT) was calculated in seconds. Results The injured group performed significantly worse in 3 directions of SEBT than the uninjured group (P \u3c 0.05). SLHT was significantly slower in the injured group compared to the uninjured group (P \u3c 0.05). Statistically significant, strong to moderate inverse relationships were found between the numbers of LAS and each of the three directions of the SEBT (P ≤ 0.01). No relationship was revealed between the number of LAS and the SLHT (P \u3e 0.05). Conclusion(s) Adolescent athletes with a history of LAS exhibit functional performance deficits on the SEBT and SLHT. Therefore, the SEBT and SLHT may provide clinicians cost- and time-effective objective tools

Cross-cultural adaptation, reliability, and validation of the Korean version of the identification functional ankle instability (IdFAI)

Purpose: To cross-culturally adapt the Identification Functional Ankle Instability for use with Korean-speaking participants. Methods: The English version of the IdFAI was cross-culturally adapted into Korean based on the guidelines. The psychometric properties in the Korean version of the IdFAI were measured for test-retest reliability, internal consistency, criterion-related validity, discriminative validity, and measurement error 181 native Korean-speakers. Results: Intra-class correlation coefficients (ICC2,1) between the English and Korean versions of the IdFAI for test–retest reliability was 0.98 (standard error of measurement = 1.41). The Cronbach’s alpha coefficient was 0.89 for the Korean versions of IdFAI. The Korean versions of the IdFAI had a strong correlation with the SF-36 (rs = −0.69, p \u3c .001) and the Korean version of the Cumberland Ankle Instability Tool (rs = −0.65, p \u3c .001). The cutoff score of \u3e10 was the optimal cutoff score to distinguish between the group memberships. The minimally detectable change of the Korean versions of the IdFAI score was 3.91. Conclusion: The Korean versions of the IdFAI have shown to be an excellent, reliable, and valid instrument. The Korean versions of the IdFAI can be utilized to assess the presence of Chronic Ankle Instability by researchers and clinicians working among Korean-speaking populations. Implications for rehabilitation The high recurrence rate of sprains may result into Chronic Ankle Instability (CAI). The Identification of Functional Ankle Instability Tool (IdFAI) has been validated and recommended to identify patients with Chronic Ankle Instability (CAI). The Korean version of the Identification of Functional Ankle Instability Tool (IdFAI) may be also recommend to researchers and clinicians for assessing the presence of Chronic Ankle Instability (CAI) in Korean-speaking population

Patellar tendon straps decrease pre-landing quadriceps activation in males with patellar tendinopathy

Objective: To determine if patellar tendon straps altered quadriceps’ muscle activity during a drop-jump landing in males with and without patellar tendinopathy. Design: Case-control. Settings: Biomechanics Research Laboratory. Participants: Twenty recreationally-active males participated: ten (age=21.3±2.4 years, height=182.8±5.3cm, mass=81.7±8.6kg) with patellar tendinopathy; ten (age=22.0±1.6 years, height=185.7±4.5 cm, mass=82.2±9.8kg) were healthy with no history of tendinopathy. Main Outcome Measures: Electromyography (EMG) data for the vastus medialis (VM), rectus femoris (RF), and vastus lateralis (VL) muscles were collected. Five 2-legged 40cm drop-jumps were performed wearing a patellar tendon strap and 5 with no-strap in a counterbalanced order. Root-mean square EMG (REMG) values of the VM, RF, and VL were averaged for a pre-landing and post-landing interval. Multiple mixed-model two-way ANOVAs were performed to determine the effect of tendinopathy and strapping condition on REMG values for each muscle. Results: For the pre-landing interval, all participants displayed lesser VL EMG activation (0.44±0.19%, 0.53±0.27%, respectively; p=.007, d=0.39) in the no-strap compared with the strap condition. Conclusions: When wearing a strap, all participants demonstrated lower VL activation prior to landing which may be helpful in reducing tensile stress at the tendon. These effects may be clinically important in modulating pain in those with patellar tendinopathy

Patellar Tendon Straps Decrease Pain and May Alter Lower Extremity Kinetics in Those With Patellar Tendinopathy During Jump Landing

Patellar tendinopathy is often managed with a patellar tendon strap, however, their effectiveness is unsubstantiated. The purpose of this study was to determine if straps altered pain or lower extremity kinetics of individuals with patellar tendinopathy during landing. Thirty participants with patellar tendinopathy and 30 controls completed drop jumps with and without patellar tendon straps. Wearing the strap, tendinopathy participants demonstrated significantly decreased pain and reduced knee adductor moment; all participants displayed significantly decreased anterior ground reaction force while wearing a strap. Patellar tendon strapping may reduce pain due to alterations in direction and magnitude of loading

Review of Physical Activity Benefits and Potential Considerations for Individuals with Surgical Fusion of Spine for Scoliosis

International Journal of Exercise Science 10(2): 166-177, 2017 Evidence-based recommendations for physical activity following spinal fusion surgeries for idiopathic scoliosis are limited, specifically in the adolescent population. Individuals with scoliosis treated operatively or non-operatively have been reported to participate in less than 1-3 days/week of even mildly strenuous physical exercises. Over 40% of individuals with scoliosis returned to sports at a level lower than pre-operative participation levels or did not return at all post spinal fusion. It is particularly important for human movement specialists, such as physical therapists, occupational therapists, athletic trainers and kinesiologists to assist these individuals effectively transition to and maintain engagement in physical activity. This review provides a snapshot of common considerations and potential factors influencing individuals with spinal-fusion for scoliosis to participate in safe physical activity

Lower Extremity Kinematics During a Drop Jump in Individuals With Patellar Tendinopathy

Background: Patellar tendinopathy (PT) is a common degenerative condition in physically active populations. Knowledge regarding the biomechanics of landing in populations with symptomatic PT is limited, but altered mechanics may play a role in the development or perpetuation of PT. Purpose: To identify whether study participants with PT exhibited different landing kinematics compared with healthy controls. Study Design: Controlled laboratory study. Methods: Sixty recreationally active participants took part in this study; 30 had current signs and symptoms of PT, including self-reported pain within the patellar tendon during loading activities for at least 3 months and ≤80 on the Victorian Institute of Sport Assessment Scale–Patella (VISA-P). Thirty healthy participants with no history of PT or other knee joint pathology were matched by sex, age, height, and weight. Participants completed 5 trials of a 40-cm, 2-legged drop jump followed immediately by a 50% maximum vertical jump. Dependent variables of interest included hip, knee, and ankle joint angles at initial ground contact, peak angles, and maximum angular displacements during the landing phase in 3 planes. Independent-samples t tests (P ≤ .05) were utilized to compare the joint angles and angular displacements between PT and control participants. Results: Individuals with PT displayed significantly decreased peak hip (PT, 59.2° ± 14.6°; control, 67.2° ± 13.9°; P = .03) and knee flexion angles (PT, 74.8° ± 13.2°; control, 82.5° ± 9.0°; P = .01) compared with control subjects. The PT group displayed decreased maximum angular displacement in the sagittal plane at the hip (PT, 49.3° ± 10.8°; control, 55.2° ± 11.4°; P = .04) and knee (PT, 71.6° ± 8.4°; control, 79.7° ± 8.3°; P \u3c .001) compared with the control group. Conclusion: Participants with PT displayed decreased maximum flexion and angular displacement in the sagittal plane, at both the knee and the hip. The altered movement patterns in those with PT may be perpetuating symptoms associated with PT and could be due to the contributions of the rectus femoris during dynamic movement. Clinical Relevance: Based on kinematic alterations in symptomatic participants, rehabilitation efforts may benefit from focusing on both the knee and the hip to treat symptoms associated with PT