Coper Groups Research Articles

Differences in lower extremity kinematics during single-leg lateral drop landing of healthy individuals, injured but asymptomatic patients, and patients with chronic ankle instability- a cross-sectional observational study.

The lower-extremity kinematics associated with forward jump landing after an ankle injury is known to differ for patients with Chronic Ankle Instability (CAI), copers (injured but asymptomatic patients), and healthy individuals. However, the differences in the lower extremity kinematics of these groups associated with a Single-leg Lateral Drop Landing (SLDL) are unknown. The purpose of this study is to characterize the lower limb and foot kinematics during SLDL in CAI patients and to compare these characteristics with those of the copers and healthy individuals. This was a cross-sectional observational study. Nineteen participants, each, were selected from the CAI, Coper, and control groups. The lower-extremity kinematics during SLDL was measured using three-dimensional motion analysis over an interval progressing from 200 ms before landing to 200 ms after landing. Either one-way ANOVA or the Kruskal-Wallis test was used to compare the attributes of the respective groups, with each parameter measured every 10 ms. The maximum values and excursions of the parameters were established over time intervals progressing from 200 ms before landing to 200 ms after landing. Significant observations were subjected to post hoc analysis. Compared to the Coper group, the CAI group exhibited significantly smaller hip adduction angles at 160 ms, ankle dorsiflexion angles in the 110-150 ms interval, and maximum ankle dorsiflexion angles after landing. Compared to the control group, the CAI group exhibited significantly smaller excursions of MH inversion/eversion after landing. Our findings confirm the necessity of focusing on the kinematics of hip adduction/abduction and plantar/dorsiflexion during SLDL in evaluating patients with ankle injuries.

Single-legged landing behavior of high school basketball players with chronic ankle instability

ObjectivesAnterior cruciate ligament injury is one of the most serious ligamentous injuries. The purpose is to compare the impact of the ankle joint on the knee during landing between athletes with chronic instability and a control group (coper group) and to verify the effects of the kinetic chain from other joints. DesignProspective study. SettingHigh school basketball. ParticipantsParticipants were 62 female high school basketball players who had participated in team sports for >6 months. Main outcome measuresPlayer joint angles, movements, and moments. ResultsThe knee valgus moment was significantly higher in the chronic ankle instability group than in the coper group (20%–60% [p < 0.01]; 80%–100% [p < 0.05]) during landing motion. The knee valgus moment was also significantly higher during the change from the maximum knee joint flexion position to the maximum extension (p < 0.05). In addition, the landing motions of the chronic instability group may have utilized suboptimal compensatory motor strategy on the sagittal plane, depending heavily on the knee joint's abduction moment. ConclusionsOur findings indicate that the chronic ankle instability group uses a different landing strategy pattern than the coper group by changing the joint moment and joint angle during landing, which may increase the risk of anterior cruciate ligament injury.

Balance, strength and physical activity after ankle sprain: Comparison between children with chronic ankle instability and copers

ObjectiveThe aim of this study was to compare muscle strength, balance, and physical activity between children with chronic ankle instability and copers. DesignCross-sectional study. SettingPediatric Physical Therapy laboratory. ParticipantsChildren aged between 7 and 12 years old from regular schools who had a history of unilateral ankle sprain. Main outcome measuresLower extremity strength, Static and dynamic standing balance, and Level of physical activity. ResultsFifteen children with chronic ankle instability and 15 copers were recruited. Demographic data showed no differences between group except for sex and the Cumberland Ankle Instability Tool-Youth (CAITY) score. Children with CAI had a significantly lower score during the standing long jump test (p < 0.05), poorer performance of single leg stance test (p < 0.001) and Y-Balance test in the anterior, posteromedial, and posterolateral directions (p < 0.05) when compared to copers. Total METs per week was significantly higher in the copers (p < 0.05). ConclusionChildren with chronic ankle instability exhibited weaker lower limb strength, poorer static and dynamic standing balance, and participate in less physical activity compared to those in a coper group which may have future negative health consequences. Knowledge about the differences between the two groups may provide guidance for physical educators and physical therapists. (200 words)

Postural control measured before and after simulated ankle inversion landings among individuals with chronic ankle instability, copers, and controls

BackgroundPostural control measured during single-leg stance and single-leg hop stabilization has been used to estimate sensorimotor function in CAI individuals and copers. To date, studies have not used postural control tasks as a way of measuring responses to sudden changes in sensory information after simulated ankle inversion landings. Research questionA cross-sectional study was performed to identify any differences in static and dynamic postural control before and after simulated ankle inversion landings among individuals with chronic ankle instability (CAI), copers, and healthy controls. MethodsNineteen CAI individuals, 19 copers, and 19 controls participated in this study. Participants performed 3 static and dynamic balance tasks before and after simulated ankle inversion landings onto a 25° tilted platform from a height of 30 cm. The main outcome measures were the center of pressure (COP) velocity and range from the single-leg stance, as well as the dynamic postural stability index from the single-leg hop stabilization. The Wilcoxon signed-rank test was used to compare posttest and pretest differences in static and dynamic postural control between groups. ResultsIn the static postural control measures, the CAI group had a higher difference in COP velocity and COP range in the frontal plane (p < 0.05 and p < 0.05, respectively) than the coper group. In the dynamic postural control measures, the CAI group demonstrated a higher difference in the vertical stability index (p < 0.05) than the healthy control group. SignificanceCAI individuals have persistent worse postural control after somatosensory modulation due to their inability to adapt to sudden somatosensory modulation. Relative to CAI individuals, copers may have different abilities not only the integration of somatosensory input about ankle inversion modulation, but also the adaptation of the entire motor control system, preventing recurrent ankle sprains after an initial LAS. Therefore, somatosensory modulation may be the indicator of understanding CAI and coper.

Factors associated with persistent pain in college athletes with a history of lateral ankle sprain

ObjectivesTo determine the factors associated with and prevalence of persistent pain in college athletes with chronic ankle instability (CAI) and with previous lateral ankle sprain (LAS) without CAI. DesignCross-Sectional Study. SettingOnline survey at one university. ParticipantsOf the 385 respondents surveyed online, 140 were identified as having experienced at least one LAS (CAI group: 69, coper group: 24, LAS group not classified as either: 47). Main outcome measuresFactors associated with the presence of pain during activities of daily living (ADL) and sports were identified using multivariate logistic regression analyses. Independent variables were demographics, injury characteristics, the Identification of Functional Ankle Instability (IdFAI) score, the Foot and Ankle Ability Measure Sports (FAAM-Sports) and ADL subscales, and the Tampa Scale for Kinesiophobia-11 score. ResultsThe prevalence of pain during ADL and sports in the three groups was 16.7%–42.0% and 33.3%–56.5%, respectively. FAAM-Sports and IdFAI score were significantly associated with pain during ADL and sports in the CAI group (odd ratio: 0.923 and 1.145), respectively. No significant pain-related factors were found in the coper and LAS groups. ConclusionsLower self-reported function and greater perceived ankle instability may be important factors in pain management in athletes with CAI.

Characteristics of the static muscle stiffness of ankle plantar flexors in individuals with chronic ankle instability.

Individuals with chronic ankle instability (CAI) have deficits in closed kinetic chain dorsiflexion that may perpetuate injury. Determining the characteristics of muscle stiffness in the plantar flexors of individuals with CAI may help in developing appropriate treatments. We aimed to highlight the characteristics of static muscle stiffness in ankle plantar flexor muscles during the passive dorsiflexion of the ankle joint in individuals with CAI. A total of 30 patients were included in the study based on the International Ankle Consortium criteria. The patients were categorized evenly into healthy, coper, and CAI groups (i.e., 10 patients in each group). After measuring the dorsiflexion range of motion (non-weight-bearing/weight-bearing) of the ankle joint, the static muscle stiffness measurements of the medial gastrocnemius, lateral gastrocnemius, soleus, and peroneus longus were obtained. The measurements were performed during the knee joint's extension and 50° flexion and passive dorsiflexion between the range of 40° plantar flexion and 20° dorsiflexion. The dorsiflexion range of motion of the CAI group was significantly smaller than that of the healthy and coper groups in the weight-bearing position. No interaction was observed for muscle stiffness in both the knee flexion and extension positions, and no significant differences were identified among the three groups. The shear modulus of the soleus at 20° ankle dorsiflexion with knee flexion had a significant negative correlation with the weight-bearing range of motion of the ankle. The limitation in the weight-bearing dorsiflexion range of motion in CAI was largely due to factors other than the increased elasticity of the ankle plantar flexor muscles.

Disrupted vision impairs force steadiness and accuracy in chronic ankle instability patients.

The primary purpose of this study was to examine the effect of visual disruption on submaximal force steadiness and accuracy among three groups including chronic ankle instability (CAI) patients, lateral ankle sprain copers, and healthy controls. Twentypatients with CAI, 20 copers, and 20 matched-healthy controls volunteered to participate in the study. Submaximal force steadiness and accuracy for evertors, invertors, and hip abductors (10% and 20% of their maximal voluntary isometric contraction) were measured with an isokinetic dynamometer. All groups performed the tasks with and without stroboscopic glasses. The CAI group showed worse steadiness and accuracy in evertors with visual disruption compared to nonvisual disruption (p < 0.0001 and = 0.02, respectively). Relative to the control group, the CAI group showed worse force steadiness and accuracy in evertors (p < 0.0001, both), worse force accuracy in hip abductors (p = 0.02), and the coper group also showed worse accuracy in evertors (p = 0.02). Individuals with CAI demonstrated impaired force steadiness and accuracy in evertors and hip abductors compared to healthy controls. In addition, they tended to rely more on visual feedback during the force steadiness task than copers and healthy controls.

The Effect of Leg Dominance and Group Difference in Star Excursion Balance Test between Individuals with Chronic Ankle Instability, Ankle Sprain Copers and Healthy Controls.

To evaluate patients with chronic ankle instability (CAI), copers who had a sprain without instability, and healthy controls using the Star Excursion Balance Test (SEBT). In addition, the reach distance was assessed between the both legs in terms of dominant and non-dominant in all groups. A total of 75 subjects (25 healthy, 25 CAI, and 25 Coper) participated. The maximum reach distance in SEBT was assessed in anterior (ANT), postero-medial (PM), and postero-lateral (PL) directions in both legs for each subject. All data were analyzed by SPSS version 21. Tukey post hoc test was used to compare all groups. Paired T-test was used to compare dominant and non-dominant legs in each group. In 75 subjects have participated in the data collection, no significant differences were reported among all groups for age and BMI measurements. Significant lower reach distance in scores of ANT in the dominant leg of the CAI was demonstrated when compared with the control and the coper groups (P=0.008). No statistical significant difference was determined between the dominant and non-dominant legs in each group (P>0.05). It seems that relevant strategies for postural control should be taken into account in the rehabilitation setup of individuals with CAI.

Foot and Shank Coordination During Walking in Copers Compared With Patients With Chronic Ankle Instability and Controls

Chronic ankle instability (CAI) alters sensorimotor function and joint coordination, but ankle coordination during walking in copers (patients with a history of ankle sprain without any residual symptoms of CAI) remains unknown. To identify foot and shank coordination patterns that discriminate among individuals with CAI, copers, and healthy controls and to investigate whether copers display a different strategy to overcome altered sensorimotor function after a lateral ankle sprain compared with individuals with CAI and healthy controls. Controlled laboratory study. A total of 51 participants (17 participants with CAI, 17 copers, 17 healthy controls) walked on an instrumented treadmill at a fixed speed of 1.20 m/s for a 10-second trial, from which 8 consecutive gait cycles were extracted for analysis. Heel strike and toe-off were identified for each stance phase, and each stance phase was normalized to 100 time frames. A curve analysis was performed to detect group mean differences in vector coding coupling angles and coordination variabilities for sagittal plane ankle motion/transverse plane tibial plane motion (SAK/TT) and frontal plane ankle motion/transverse plane tibial motion (FAK/TT) with 90% CIs. During the terminal stance, CAI and coper groups demonstrated an inversion-tibial external rotation coupling, while controls displayed a dorsiflexion-tibial internal rotation strategy. During midstance, there were no differences between the coper, CAI, or control groups. At 0% to 20% of stance, the CAI group showed the most variability, while copers showed the least. During midstance, both copers and controls displayed an increase in variability earlier than the CAI group. The CAI group displayed a peak in variability from 39% to 43% of stance, which was greater than copers. During the propulsive phase (from heel-off to toe-off), the CAI group showed greater SAK/TT variability than both copers and controls. Similar to SAK/TT variability, the CAI group showed an earlier peak in FAK/TT variability compared with controls. The CAI, coper, and control groups displayed different ankle joint coupling patterns and coordination variability during a walking gait cycle. Copers may have the ability to alter their coordination during walking, which may help us understand the underlying mechanism of CAI.

Coper has altered foot joint coordination pattern compared to individuals with chronic ankle instability during running

BackgroundThere is limited information regarding the cause for the different etiologies in individuals with initial lateral ankle sprains (LAS) who have chronic ankle instability (CAI) and no recurrence or instability for > 12 months (copers) following initial LAS. Assessing the movement patterns of copers and individuals with CAI and LAS recurrence is essential for identifying the mechanical factors that affect patient outcomes. Research questionDoes coordination and coordination variability of rearfoot, midfoot, and forefoot present a potentially causative pattern for CAI or coper? MethodsThis cross-sectional study included 35 males who were divided into the CAI (n = 13), coper (n = 12), and control group (n = 10). Participants performed rearfoot strike running on the treadmill at a fixed speed of 3.5 m/s. The coupling angle between the rearfoot, midfoot, and forefoot, representing intersegmental coordination, was calculated using the modified vector coding technique and categorized into four coordination patterns. The coupling angle standard deviation served represented coordination variability during the stance phase. ResultsOne control participant and one CAI participant were excluded, and final analyses were performed on the CAI (n = 12), coper (n = 12), and control (n = 9) groups. During late stance, the coper group showed a significantly greater proportion of in-phase with distal dominancy (p = 0.02, effect size=0.17) and a significantly lower proportion of in-phase with proximal dominancy (p = 0.05, effect size=0.17), than the CAI group. During the early stance, the coper group showed a significantly lower proportion of anti-phase with distal dominancy than the CAI group (p = 0.03, effect size=0.18). There were no differences in intra-foot variability among the groups. SignificanceThe intra-foot coordination observed in the coper group suggests that this movement pattern may reduce the risk of ankle sprains.

Higher Leg and Trunk Muscle Activation during Balance Control in Copers versus People with Chronic Ankle Instability and Healthy Female Athletes.

HighlightsAthletes with a history of ankle sprain that do not suffer from ankle instability (copers) exhibit similar balance and neuromuscular control compared to healthy athletes.Athletes with chronic ankle instability show a deficit in neuromuscular control and balance, which may increase the risk of subsequent injuries.Athletes with chronic ankle instability are advised to use neuromuscular training in their rehabilitation program to improve balance and neuromuscular performance to reduce the risk of injury.More than 70% of people with ankle sprain experience chronic ankle instability. However, some people are well adapted to this damage (copers) and do not suffer from chronic ankle instability (CAI). This cross-sectional study involved 34 female athletes, who were classified into three groups (athletes with CAI, copers, and healthy athletes) and tested on a Biodex Balance System. Surface electromyography (EMG) and balance scores were monitored. The coper and healthy group exhibited higher medial gastrocnemius (MG) EMG activity during unstable balance conditions. The rectus abdominus (RA) in the coper group and rectus femoris (RF) in the healthy group showed greater EMG activity compared to CAI during unstable conditions. During stable conditions, the coper group showed greater RA EMG activity compared to CAI, as well as higher tibialis anterior (TA) EMG activity compared to the healthy group. Additionally, balance error scores were higher in the CAI group than those in the healthy group under unstable conditions. In conclusion, decreased EMG activity of the MG, RF, and RA in CAI athletes may contribute to impaired balance in these individuals. The increased EMG activity of the MG, TA, and RA in copers might result in more trunk and ankle stability.

Copers adopt an altered dynamic postural control compared to individuals with chronic ankle instability and controls in unanticipated single-leg landing

BackgroundSeveral prior studies involving “expected” single-leg landings have not succeeded in establishing a difference between copers and a control group. Research questionDoes expected and unanticipated single-leg landing affect dynamic postural stability in lateral ankle sprain individuals with chronic ankle instability (CAI), copers, and controls? MethodsIn this prospective cross-sectional study, physically active adults with CAI (n = 12), copers (n = 12), and controls (n = 12) were included. Participants performed expected single-leg landing by stepping off a 30-cm box. They also performed unanticipated landings including side-step cutting, side-step cutting at 60°, single-leg landing, and forward stepping. The expected and unanticipated conditions of each groups were compared in terms of time to stabilization (TTS) and center of pressure (COP) for the anterior-posterior (AP) and medial-lateral (ML) conditions. To analyze the data, a mixed-model one-way analysis of variance and a Tukey-Kramer post hoc test were performed. ResultsA significant condition × group interaction was observed in only TTS ML, with the CAI group demonstrating a significantly longer TTS ML than the coper (p < 0.001) and control (p < 0.001) groups during unanticipated trials. In addition, group interaction effects were observed for COP AP and TTS AP. The coper group demonstrated significantly longer COP AP and TTS AP than the control group (p < 0.001). SignificanceThe CAI group demonstrated a significantly longer TTS ML than the coper and control groups during the unanticipated condition, and the coper group demonstrated significantly longer TTS AP and COP AP than the control group. Thus, longer COP AP and TTS AP sway time in the coper group may be a protection mechanism, allowing greater freedom in the AP plane while quickly controlling ML sway and preventing lateral ankle sprains. These findings can help in the prevention of lateral ankle sprains and assessment of dynamic postural control.

Running gait biomechanics in females with chronic ankle instability and ankle sprain copers

ABSTRACT Limited evidence exists comparing running biomechanics between individuals with chronic ankle instability (CAI) and those who fully recover (copers). The purpose of this study was to simultaneously analyse running gait kinematics, kinetics, and surface electromyography (sEMG) between ankle sprain copers and individuals with CAI. Twenty-six (13 CAI, 13 Coper) recreationally active females participated and ran shod on an instrumented treadmill at 2.68 m/s. We assessed lower extremity kinematics and kinetics and sEMG amplitude for the fibularis longus, tibialis anterior, medial gastrocnemius, and gluteus medius muscles. Ten consecutive strides from the beginning of the trial were analysed using statistical parametric mapping (SPM) independent t-test. The CAI group had significantly more ankle inversion during 0–6%, 42–53%, and 96–100% of the running stride cycle compared to the coper group. At initial contact (0%), the CAI group was in an inverted ankle position (5.9°±6.8°) and the coper group was in an everted ankle position (−3.2°±5.5°; p = 0.01, d = 1.5). There were no significant differences identified for any other outcome measures. Increased ankle inversion during the swing phase leading into the loading phase is concerning because the ankle is in an open packed position and inversion is a primary mechanism of injury for sustaining a lateral ankle sprain.

Altered Biomechanics in Individuals With Chronic Ankle Instability Compared With Copers and Controls During Gait.

Given that motions of 1 segment affect those of an adjacent segment, the authors of biomechanical studies must thoroughly investigate the kinematics and kinetics of the proximal joints (hip and knee) as well as the ankle joints in patients with chronic ankle instability (CAI). However, few researchers have investigated the altered movement strategies of the lower extremities of patients with CAI compared with lateral ankle-sprain (LAS) copers and control participants throughout the full gait cycle of walking and jogging. To evaluate lower extremity biomechanical differences in patients with CAI, LAS copers, and control individuals during gait. Case-control study. Controlled laboratory setting. A total of 54 participants, consisting of 18 patients with CAI (age = 24.6 ± 2.8 years, height = 173.0 ± 8.0 cm, mass = 67.8 ± 14.6 kg), 18 LAS copers (age = 26.0 ± 4.6 years, height = 173.4 ± 7.5 cm, mass = 66.9 ± 10.3 kg), and 18 control individuals (age = 26.2 ± 2.3 years, height = 172.2 ± 8.2 cm, mass = 63.3 ± 11.2 kg). Three-dimensional kinematics and kinetics of the lower extremity during walking and jogging. The CAI group exhibited dorsiflexion deficits and more inverted ankles compared with the LAS coper and control groups during walking and jogging. In addition, the LAS coper group generated greater knee internal-rotation moments than did the CAI group during jogging. The other variables did not differ among groups. Participants with CAI demonstrated altered biomechanics, which need to be addressed via intervention programs.

Comparison Between Spatiotemporal Parameters and Vertical Ground Reaction Force in Ankle Sprain Coper and Healthy Athletes: A Cross Sectional Study

Purpose: It is essential to maintain dynamic stability during walking to perform daily tasks independently. The present study aimed at comparing the spatiotemporal parameters and the values of the vertical Ground Reaction Force (vGRF) as well as determining the time to reach them in ankle-sprain coper and healthy athletes during the stance phase of gait. Methods: A total of 28 female university athletes were recruited in this cross-sectional study and assigned into two groups: ankle-sprain coper (n=14) and healthy control (n=14). The gait cycle analysis was then performed on a 10-m path, and the information related to the stance phase was recorded by a foot scanning device. The spatiotemporal parameters (gait line and contact time) and the values of the vGRF along with the time to reach them were subsequently obtained from each test. The repeated measures Analysis of Variance (ANOVA) was additionally used to analyze the data (P≤0.05). Results: The study results revealed no differences between the injured and the healthy feet in the ankle-sprain coper group in any of the variables (P&gt;0.05). As well, the spatiotemporal gait cycle parameters between the ankle-sprain coper group and the healthy controls were not significantly different (P&gt;0.05). However, significant differences were observed between the ankle-sprain coper and healthy controls in terms of the variables of the vGRF in the mid-stance (F=5.25, P=0.03) and the time to reach the second peak of the vGRF (F=9.13, P=0.006). Conclusion: The spatiotemporal gait parameters were not significantly different between the ankle-sprain coper and the control groups, but the vGRF in the ankle-sprain coper was greater than that in the control group. With regard to the correlation between the reduction in the vGRF and the secondary injury, it is recommended to pay much attention to this point in rehabilitation programs following the first injury in female athletes.

Individuals with chronic ankle instability exhibit altered ankle kinematics and neuromuscular control compared to copers during inversion single-leg landing

ObjectivesThis study compares the ankle kinematics and muscle activities of the individuals with chronic ankle instability (CAI), coper, and control groups in normal and inversion single-leg landings. Designcross-sectional study; SettingBiomechanics laboratory. ParticipantsPhysically active adults with CAI (N = 12); and coper (N = 12) and control (N = 12) groups. Main outcome measuresThe participants performed normal and inversion single-leg landing. The muscle activity 200 ms before and after landing of the tibialis anterior, the medial gastrocnemius, and the fibularis longus (FL) were recorded. The FL latency, sagittal and frontal co-contraction indexes (CCI), ankle inversion angle at the initial contact, and the maximum inversion angle were recorded. ResultsSignificantly longer FL latency, decreased FL muscle activity, frontal CCI, and an increased maximum inversion angle at post-landing were discovered during inversion single-leg landing in the CAI group compared to the coper and control groups. However, no significant difference was observed among the CAI and coper groups during normal single-leg landing. ConclusionThese results suggest prolonged FL latency and altered ankle kinematics suggest an increased risk of recurrent lateral ankle sprains in CAI with inversion single-leg landing.

CAN PROXIMAL HIP STRENGTH AND DYNAMIC CONTROL DIFFERENTIATE FUNCTIONAL ANKLE STABILITY CLASSIFICATIONS?

Ankle instability can be problematic in an active population with multiple risk factors associated with recurrence. The aim of this study was to determine if deficits in weight-bearing and non-weight bearing assessment of hip strength or dynamic balance in lower extremity reaching tasks from flat and inclined surfaces can differentiate subjects classified as controls, ankle sprain copers, or those with chronic, recurrent ankle sprains. Quasiexperimental, Ex post facto. A convenience sample of 60 subjects was classified into control, coper, or chronic ankle sprain groups based on the results of the Identification of Functional Ankle Instability Questionnaire. Subjects were tested for peak force production of their hip extensors, hip abductors, and a composite of hip extension and external rotation while in a standing position using a hand-held dynamometer. Additionally, each subject performed a modified Star Excursion Balance Test in anterior, posterolateral, and posteromedial directions from both a flat and 15 ° inverted stance position. One-way analysis of variance was calculated for between group differences of hip strength and balance reach ability and ankle stability classification. Pearson product-moment correlation coefficients were derived to evaluate relationships between hip strength and dynamic balance tests. Twenty-one subjects were assigned to the control group, 23 to the coper group, and 16 to the chronic group. There were no significant differences between groups in self-report of Foot and Ankle Ability Measures or Tegner activity levels. Mean hip strength was not significantly different between ankle sprain classification groups (p = 0.66 - 0.82). The mean limb symmetry index for hip strength comparing injured and uninjured ankles was nearly symmetrical in all ankle stability groups (p = 0.34 - 0.97). The same symmetry was present when comparing injured and uninjured abilities for all dynamic balance reach tasks from both flat and inclined surfaces. (p = 0.16 - 0.62). There was a fair relationship between hip extension and weight-bearing hip extension/external rotation strength and the posteromedial and posterolateral reach tasks with correlation coefficients in the range of 0.33 - 0.43. Performance measures of tri-planar, static, isometric hip strength and lower extremity reach in dynamic balance tasks could not differentiate subjects without a history of injury from those subjects with one or more lateral ligamentous ankle sprains. 2b; Ex post facto.

Health-Related Quality of Life Among Middle-Aged Adults With Chronic Ankle Instability, Copers, and Uninjured Controls.

People with chronic ankle instability (CAI) display a lower regional and global health-related quality of life (HRQoL). Examinations of HRQoL outcomes associated with CAI have addressed younger adults, restricting our understanding of the long-term consequences of CAI. To compare ankle regional and global HRQoL in middle-aged participants with and those without CAI. Cross-sectional study. Laboratory. A total of 59 middle-aged volunteers, consisting of 18 with CAI (age = 50.2 ± 9.3 years), 17 who were ankle-sprain copers (age = 54.5 ± 8.7 years), and 24 uninjured controls (age = 56.7 ± 10.0 years). Participants completed the Foot and Ankle Disability Index (FADI) and the Patient-Reported Outcomes Measurement Information System Adult Profile. Regional HRQoL was assessed using the FADI Activities of Daily Living and Sport subscales. Global HRQoL was measured using the 43-item Patient-Reported Outcomes Measurement Information System Adult Profile, which contains 7 short forms-Physical Function, Pain Interference, Fatigue, Depression, Sleep Disturbance, Anxiety, and Ability to Participate in Social Roles and Activities. Separate Kruskal-Wallis tests were used to determine between-groups differences. Middle-aged participants with CAI had lower scores on both subscales of the FADI than the coper and control groups (all P values <.001). Participants with CAI scored lower on the Physical Function (U = 116.0, z = -2.78, P = .005) and Ability to Participate in Social Roles and Activities (U = 96.0, z = -3.09, P = .002) subscales but higher on the Pain Interference (U = 144.0, z = -2.36, P = .02), Fatigue (U = 110.0, z = -2.72, P = .006), and Depression (U = 110.5, z = -2.91, P = .004) subscales than the control group. Participants with CAI also scored lower on the Physical Function (U = 74.5, z = -2.79, P = .005) and Ability to Participate in Social Roles and Activities (U = 55.0, z = -3.29, P = .001) subscales but higher on the Fatigue (U = 90.0, z = -2.09, P = .04) and Depression (U = 96.5, z = -1.97, P = .048) subscales than the coper group. Middle-aged participants with CAI displayed worse ankle regional and global HRQoL than their age-matched healthy counterparts and copers. These results demonstrated that CAI can affect HRQoL outcomes in middle-aged adults.

Gluteus medius dysfunction in females with chronic ankle instability is consistent at different walking speeds

BackgroundPatients with chronic ankle instability often present with altered gait mechanics compared to ankle sprain copers. There is increasing evidence to suggest proximal neuromuscular alterations contribute to the injury etiology, however little is known about how these changes manifest during gait. The purpose of this study was to investigate ipsilateral gluteus maximus and medius functional activity ratios throughout treadmill walking at three speeds (preferred, 120% preferred, and 1.35 m per second) in chronic ankle instability patients compared to copers. Methods28 females (14 chronic ankle instability, 14 copers) walked at the three gait speeds in randomized order. Ground reaction forces and 10-s gluteal ultrasound clips were simultaneously recorded. Clips were reduced using ground reaction forces to extract 55 measurement frames. Normalized gluteal thickness measures were used to determine functional activity ratios. 2 × 3 analyses of variance were run to assess group and speed effects on gluteal outcomes throughout walking using statistical parametric mapping. Post-hoc t-tests, mean differences, and Cohen's d effect sizes were assessed for significant findings (P ≤ .05). FindingsThe chronic ankle instability group had significantly decreased gluteus medius activity throughout the entire gait cycle when compared to the coper group, independent of gait speed (P < .001, mean differences: 0.10–0.18; d: 1.00–3.17). There were no significant group or speed main effects, nor an interaction for gluteus maximus activity. InterpretationGluteal dysfunction throughout walking was identified in chronic ankle instability. The coper group remained within healthy reference muscle activity ranges, suggesting that proximal muscle activation alterations are associated chronic ankle impairments.

Alterations in Cortical Activation Among Individuals With Chronic Ankle Instability During Single-Limb Postural Control.

Chronic ankle instability (CAI) is characterized by repetitive ankle sprains and perceived instability. Whereas the underlying cause of CAI is disputed, alterations in cortical motor functioning may contribute to the perceived dysfunction. To assess differences in cortical activity during single-limb stance among control, coper, and CAI groups. Cross-sectional study. Biomechanics laboratory. A total of 31 individuals (10 men, 21 women; age = 22.3 ± 2.4 years, height = 169.6 ± 9.7 cm, mass = 70.6 ± 11.6 kg), who were classified into control (n = 13), coper (n = 7), and CAI (n = 11) groups participated in this study. Participants performed single-limb stance on a force platform for 60 seconds while wearing a 24-channel functional near-infrared spectroscopy system. Oxyhemoglobin (HbO2) changes in the supplementary motor area (SMA), precentral gyrus, postcentral gyrus, and superior parietal lobe were measured. Differences in averages and standard deviations of HbO2 were assessed across groups. In the CAI group, correlations were analyzed between measures of cortical activation and Cumberland Ankle Instability Tool (CAIT) scores. No differences in average HbO2 were present for any cortical areas. We observed differences in the standard deviation for the SMA across groups; specifically, the CAI group demonstrated greater variability than the control (r = 0.395, P = .02; 95% confidence interval = 0.34, 0.67) and coper (r = 0.38, P = .04; 95% confidence interval = -0.05, 0.69) groups. We demonstrated a strong correlation that was significant in the CAI group between the CAIT score and the average HbO2 of the precentral gyrus (ρ = 0.64, P = .02) and a strong correlation that was not significant between the CAIT score and the average HbO2 of the SMA (ρ = 0.52, P = .06). The CAI group displayed large differences in SMA cortical-activation variability. Greater variations in cortical activation may be necessary for similar static postural-control outcomes among individuals with CAI. Consequently, variations in cortical activation for these areas provide evidence for an altered neural mechanism of postural control among populations with CAI.