Ankle Kinematics Research Articles

Stance and swing phase ankle phenotypes in youth with Charcot-Marie-Tooth type 1: An evaluation using comprehensive gait analysis techniques

BackgroundCharcot-Marie-Tooth disease (CMT) results in muscle weakness and contracture leading to a wide variety of gait issues including atypical ankle kinematics in both stance and swing. Knowledge of the stance and swing phase kinematic patterns for CMT type 1 (CMT1), the most common CMT type, will improve our understanding of expected gait outcomes and treatment needs to improve gait function. Research questionWhat are the stance/swing phase ankle phenotypes in CMT1? MethodsA prospective convenience sample of 25 participants with CMT1, ages 7–19 years, underwent comprehensive gait analysis following standard procedures. Ankle phenotypes based on peak ankle dorsiflexion in terminal stance and mid-swing were defined and compared using linear mixed models. ResultsPatients with CMT1 presented with three stance phase ankle phenotypes: 21 limbs (42 %) with reduced (mean 5°, SD 2°), 19 limbs (38 %) with typical (mean 11°, SD 1°) and 10 limbs (20 %) with excessive (mean 15°, SD 2°) peak dorsiflexion in terminal stance (p < 0.05). There were two swing phase phenotypes: 19 limbs (38 %) with typical (mean −1.7°, SD 1.5°) and 31 limbs (62 %) with excessive (mean −5.6°, SD 1.4°) plantarflexion in mid-swing (p < 0.002). Eleven patients (44 %) had ankles that were classified into different stance groups, and 9 patients (36 %) had ankles that were classified into different swing groups. The most common combination of stance/swing ankle phenotypes was decreased dorsiflexion in terminal stance with increased plantarflexion in mid-swing (16 sides, 32 %). SignificanceThis study shows that youth with CMT1 have multiple combinations of combined ankle kinematics for stance and swing. The ankle phenotypes identified in this study reflect contributions of both dorsi/plantarflexor weakness and plantarflexor contracture, which require different treatment approaches. Comprehensive gait analysis can distinguish between multiple ankle phenotypes to assist in determining the most appropriate treatment to improve gait for individual patients.

Differences in causes of stiff knee gait in knee extensor activity or ankle kinematics: A cross-sectional study

BackgroundStiff knee gait (SKG), a common occurrence after the onset of stroke, is caused by hyperactivity of the rectus femoris during the swing phase. Another cause of SKG is the weakness of push-off in hemiparetic gait. Prior research did not consider the effect of the magnitude of knee extensors in their subjects. Research questionDoes the cause of SKG differ between patients with high and low knee extensor activities during the swing phase? MethodsWe examined 38 patients with chronic stroke hemiplegia who presented with SKG. After placing an inertia sensor and an electromyogram, patients walked 10 m at a comfortable speed. All patients were categorized per the sign of the principal component 2 (PC2) as a component with large factor loadings of knee extensors attained from the electromyographic amplitude during the early swing phase of the paretic limb. Then, the kinematic parameters of knee flexion and other gait parameters in each group were compared, and a correlation analysis was performed. ResultsIn the high PC2 group, the timing of peak knee flexion during the swing phase was early, and vastus lateralis activity during the preswing phase negatively correlated with the knee-flexion angle during the swing phase. In the low PC2 group, the angular velocity of ankle plantar flexion at the toe-off was slow, which positively correlated with the knee-flexion angle during the swing phase. SignificanceThe cause of SKG could be an inappropriate activity of the vastus lateralis rather than the rectus femoris in patients with high knee extensor activity and slow plantar-flexion velocity at toe-off in patients with low knee extensor activity. Not all causes of SKG in patients with hemiplegia are common, and different treatment strategies are needed per the individuality of spastic knee extensor activity.

The effects of the tension of figure-8 straps of a soft ankle orthosis on the ankle joint kinematics while walking in healthy young adults: A pilot study

BackgroundFigure-8 straps are commonly used in ankle orthoses, which are provided to reduce the risks of primary and recurrent sprain by providing functional support. Functional treatment with ankle orthoses can provide better rehabilitation than immobilization for a mild ankle sprain. However, it is not known how much tension should be applied to the straps while donning the orthosis to optimize its effectiveness. Research questionThe aim of this study was to investigate the effects of figure-8 strap tension of a soft ankle orthosis on ankle joint kinematics in the sagittal, coronal, and transverse planes during gait in healthy young adults. MethodsTen healthy adults (five males and five females) were enrolled in this study. The 3-dimensional motion analysis system was used to evaluate the ankle kinematics of the participants during gait under five conditions: no soft ankle orthosis, soft ankle orthosis with no figure-8 straps tension (lace-up only), 50 N, 80 N, and 110 N tension of the figure-8 straps, respectively. All participants walked in a straight path at a comfortable speed. ResultsPlantarflexion angles were significantly reduced with 110 N of tension in the figure-8 straps when compared to the lace-up only and a moderate correlation with r = 0.34 (p = 0.03) was observed between the tensions of figure-8 straps and maximum plantarflexion angles at pre-swing of a gait cycle. No significant effects on ankle joint angles were demonstrated in the coronal and transverse planes. SignificanceThis study showed that increasing the tension of the figure-8 straps could restrict the ankle joint plantarflexion angle during pre-swing in gait. However, it might not affect inversion/eversion or internal/external rotation angles of the ankle joint in individuals without ankle pathologies.

Biosignal processing methods to explore the effects of side-dominance on patterns of bi- and unilateral standing stability in healthy young adults.

We examined the effects of side-dominance on the laterality of standing stability using ground reaction force, motion capture (MoCap), and EMG data in healthy young adults. We recruited participants with strong right (n = 15) and left (n = 9) hand and leg dominance (side-dominance). They stood on one or two legs on a pair of synchronized force platforms for 50 s with 60 s rest between three randomized stance trials. In addition to 23 CoP-related variables, we also computed six MoCap variables representing each lower-limb joint motion time series. Moreover, 39 time- and frequency-domain features of EMG data from five muscles in three muscle groups were analyzed. Data from the multitude of biosignals converged and revealed concordant patterns: no differences occurred between left- and right-side dominant participants in kinetic, kinematic, or EMG outcomes during bipedal stance. Regarding single leg stance, larger knee but lower ankle joint kinematic values appeared in left vs right-sided participants during non-dominant stance. Left-vs right-sided participants also had lower medial gastrocnemius EMG activation during non-dominant stance. While right-side dominant participants always produced larger values for kinematic data of ankle joint and medial gastrocnemius EMG activation during non-dominant vs dominant unilateral stance, this pattern was the opposite for left-sided participants, showing larger values when standing on their dominant vs non-dominant leg, i.e., participants had a more stable balance when standing on their right leg. Our results suggest that side-dominance affects biomechanical and neuromuscular control strategies during unilateral standing.

Donor-Site Morbidity after Osteocutaneous Free Fibula Transfer: Longitudinal Analysis of Stair Climbing Asymmetry and Functional Outcome

The autologous vascularised free fibula flap is currently considered the best option for facial reconstruction after oncological surgery, but its donor-site morbidity has not been fully examined. The purpose was to evaluate donor-site changes in temporal and spatial kinematic gait parameters during stair climbing, as well as the gait symmetry. Fourteen patients (48 ± 16 years) were evaluated before and six months after harvest of a vascularised free fibula flap. Temporal gait variables for both the ascent and descent phases did not change after surgery (2-way ANOVA, p &gt; 0.05). During stair ascent, ankle flexion (healthy side, increased; donor side, reduced; low effect size) had a significant time × side interaction. During stair descent, hip flexion was significantly larger on the donor side (medium effect size). Significant time × side interactions were observed for ankle inversion (healthy side, reduced; donor side, increased; and low effect size) and knee flexion (healthy side, increased; donor side, unchanged; and low effect size). Medium effect sizes were found for hip flexion side differences (significant). No relevant spatio-temporal nor kinematic asymmetry emerged apart from ankle joint kinematics. Overall, only the side effect of hip flexion during descent was both statistically significant and practically meaningful. Considering the slight modifications of the gait variables, no major functional limitations were found following vascularised free fibula flap reconstruction during stair climbing and descent.

Ankle Kinematics In New And Old Footwear During An Inversion Ankle Sprain Perturbation

Ankle Kinematics In New And Old Footwear During An Inversion Ankle Sprain Perturbation

Kinematic alterations of the ankle in subjects with generalized joint hypermobility compared with the controls: A cross-sectional study.

Generalized joint hypermobility (GJH) is a hereditary connective tissue disease in which the range of motion (ROM) of multiple joints exceeds the normal range, and the ROM varies with age, gender, and ethnicity. At present, the six-degree-of-freedom (6-DOF) of ankle kinematics among people with GJH have not been studied. To investigate the kinematic characteristics in the ankle during treadmill gait of university students with generalized joint hypermobility compared to normal participants. We hypothesized that compared to the participants in the control group, those with GJH would exhibit kinematic characteristics of poorer active motion stability in the ankle during treadmill gait. Healthy university student volunteers aged 18-24 (excluding those with a history of ankle trauma, etc.) were recruited and divided into a control group (50 volunteers) and a GJH group (Beighton score ≥4, 50 volunteers). Data of the 6-DOF kinematics of ankle was collected using a 3D gait analysis system. Variables were evaluated using independent t-tests and Wilcoxon signed-rank tests. In the proximal/distal parameter, proximal displacement was significantly increased in the GJH group compared with the control group during 4-9% and 96-97% of the gait phase (loading response and terminal swing phase), with an increase of (0.1-0.2cm, p < .05). Regarding the proximal/distal, internal/external, plantarflexion/dorsiflexion, and anterior/posterior parameters, the participants with GJH exhibited greater ROM than those in the control group throughout the gait cycle (0.24 ± 0.22cm vs. 0.19 ± 0.15cm, p = 0.047, 5.56 ± 2.90° vs. 4.48 ± 3.30°, p = .020, 23.05 ± 5.75° vs. 20.36 ± 4.91°, p < .001, 0.65 ± 0.30cm vs. 0.55 ± 0.27cm, p = .018). However, ROM of inversion/eversion translation was found to be decreased in the GJH group compared to the control group (8.92 ± 1.59° vs. 9.47 ± 1.37°, p = .009). In addition, there was no statistical difference between the GJH group and the control group in ROM of medial/lateral translation (0.05 ± 0.06cm vs. 0.04 ± 0.05cm, p = .131). Our results confirm that our hypothesis is not valid. Although there were a few differences in each gait parameter of the ankle between the GJH group and the control group, the difference was not significant. These results indicate that the presence of GJH has less effect on ankle kinematics and enhance our knowledge of the relationship between GJH and 6-DOF of ankle kinematics.

Knee Joint Loading Distribution With Vest-borne Loads

Vest borne loads increase tibiofemoral joint (TFJ) contact forces, but the TFJ contact forces do not always increase proportionally to the increase in load (Lenton et al., 2018). It is unclear if and how increase in TFJ contact forces are attenuated during load carriage.PURPOSE: To determine the effects of load carriage on total, medial (MTFJ), and lateral (LTFJ) tibiofemoral joint contact forces, and to determine if increases in joint loads are attenuated via gait adaptations. METHODS: Twelve young, healthy adults (6 males [BMI = 22.19] and 6 females [BMI = 20.38]; 22 + 1.6 yrs), walked for 5 minutes per condition at 1.4 m·s-1 on an instrumented treadmill while carrying vest borne loads of 0%, 15%, and 30% body weight during 3D motion capture. Hip, knee, and ankle kinematic and kinetic data were used as inputs to an inverse-dynamics informed musculoskeletal model of axial TFJ contact force. Kinematic and TFJ contact force comparisons were made via repeated measures ANOVA. RESULTS: From 0% load to 15% and from 0% to 30%, total peak TFJ increased 14% and 32% (3.44 vs 3.92 vs 4.55 body weights (BW) p < 0.001); peak MTFJ increased 12% and 26.5% (2.42 vs 2.72 vs 3.05 BW, p < 0.001); peak LTFJ increased 13% and 38% (1.29 vs 1.46 vs 1.79 BW, p < 0.001), and leg stiffness decreased 10% and 28% (7.17 vs 6.46 vs 5.10 N/mm, p < 0.001), respectively. CONCLUSION: Young, healthy participants do not attenuate the increase in total and medial knee joint contact forces with increasing magnitude of load carriage. They respond to load by decreasing joint stiffness through small increases in dorsiflexion, knee flexion, and hip flexion, which does increase shock absorption and assists with energy transfer (Kinoshital, 1985). These minor increases in flexion coupled with increases in vertical ground reaction forces led to the approximately proportional relative percent increase in TFJ and MTFJ as compared to the increase in load. However, the increase in LTFJ from 0% load to 30% load was 8% greater indicating a disproportional increase in the lateral compartment, assuming that “disproportional” is greater or less than 5%. Further research should investigate if greater increases in load magnitude continue to lead to proportional increases in total TFJ and MTFJ, and disproportional increases LTFJ, especially in military populations who frequently carry heavy loads.

Knee Joint Loading And Realtime Vertical Ground Reaction Force Biofeedback With Vest-Borne Loads

Realtime biofeedback has been used to modify gait and decrease knee joint loading. Vertical ground reaction force (vGRF) may offer broad utility as a feedback option to alter tibiofemoral joint (TFJ) contact forces during gait. For example, individuals that carry heavy loads experience increased TFJ contact force. vGRF feedback may reduce effect at the TFJ. PURPOSE: To investigate the effectiveness of vGRF feedback for reducing axial TFJ contact force during load carriage. METHODS: Twelve healthy adults (22 + 1.6 yrs), walked for 5 minutes per condition at 1.4 m·s-1 on an instrumented treadmill while carrying vest borne loads of 0%, 15%, and 30% body weight during 3D motion capture, with and without vGRF feedback to reduce peak vGRF below a set threshold. Hip, knee, and ankle kinematic and kinetic data were used as inputs to an inverse dynamics informed musculoskeletal model of axial TFJ contact force. Comparisons of peak TFJ contact force were made via 3x2 repeated measures ANOVA and post hoc paired T-Tests. RESULTS: vGRF feedback led to a total peak TFJ contact force increase of 25% at no load, 55% at 15% load, and 82% at 30% load as compared to no load no feedback. Each load condition with feedback elicited greater peak TFJ contact force than no feedback. (0% [3.44 vs 4.30 Body Weights (BW), p = 0.008]; 15% [3.92 vs 5.34 BW, p = 0.002]; 30% [4.55 vs 6.27 BW, p < 0.001], Figure 1). CONCLUSION: To reduce peak vGRF, participants slightly reduced their stride length and adopted a crouched gait characterized by increased knee and hip flexion. The increase in flexion increased estimated quadriceps and hamstrings force, ultimately leading to large increases in total TFJ contact forces. Although readily available than more sophisticated options to alter TFJ contact force, feedback of peak vGRF is not effective for reducing TFJ contact force with or without load carriage. Realtime feedback of TFJ contact forces would likely be an optimal choice of feedback if attempting to decrease knee joint loads.

Gait-related Factors That Explain Power Production In Patients Before And After Total Ankle Arthroplasty

Total ankle arthroplasty (TAA) reduces pain and improves joint function, including power production at the ankle. Patients can ambulate at higher velocities and generate greater joint power after TAA. To date, little is known about which factors – angular velocity (AV), ground reaction force (GRF), or range of motion (ROM) – most influence power production before and after TAA. Identifying the factors that affect power production and their relative contribution can provide rehabilitation targets. PURPOSE: To examine the role of ankle kinematics and kinetics in generating power in the last third of the stance phase and to evaluate which factors play the most important role in generating increased power after surgery. It is hypothesized that reduction in pain will primarily increase GRF and AV to a greater degree than ankle ROM. METHODS: Two hundred and eighteen patients (101 male and 117 female; age = 63.1 + 9.4) with requiring TAA were studied using a motion analysis system and force plates before and after TAA. Peak ankle power and associated vertical GRF (vGRF), center of pressure (COP) position, ankle angle, moment and AV were compared before and after surgery using Wilcoxon signed rank tests. Predictive models for pre and post surgical power generation were created using AIC multiple stepwise regression. RESULTS: Following TAA, ankle plantarflexion power increased on both the surgical and nonsurgical limbs (0.83 to 1.1, p < 0.001; 0.97 to 1.4, p < 0.001 respectively). To increase power, patients increased surgical and non-surgical side vGRF (0.51 to 0.58, p < 0.001; 0.51 to 0.57, p = 0.002 respectively) and AR (1.1 to 1.7, p < 0.001; 1.1 to 1.8, p < 0.001 respectively). Ankle ROM did not change significantly on either limb following surgery. Ankle AV and vGRF are the best predictors of peak plantar flexion power across all models, with AV being the strongest single predictor. CONCLUSIONS: TAA improves power production at the ankle by allowing patients to generate a greater force at a higher rate. Increased power production relates to faster and more efficient gait, relieving other joints of the need to generate compensatory power. Pre and post-TAA treatment strategies should focus on helping patients increase vGRF and plantarflexion angular velocity during terminal stance to improve physical functional before and after TAA.

Alterations to plantar loading and ankle range of motion of the contralateral foot during assisted walking in patients with Type 2 Diabetes Mellitus

AimsPatients with diabetic foot ulcers are instructed to be non-weight bearing on the affected limb to promote healing. Therefore, the aim of this study was to investigate the effect of different assistive devices on whole foot plantar loading, peak forefoot force, ankle range of motion, and locomotion speed during gait in patients with Type 2 Diabetes Mellitus. MethodsParticipants walked normally, with crutches, a walker, and a wheeled knee walker (WKW) in randomized order. Force sensitive insoles and 3D motion capture were used to record plantar normal force and ankle kinematics. Force sensitive pads were wrapped around handles of the crutches and walker to measure bodyweight offloaded onto the assistive device. An instrumented WKW was used to measure bodyweight offloaded onto the handlebars and knee cushion. ResultsLocomotion with the WKW produced the lowest whole foot plantar loading and peak forefoot force in the propulsive limb, while also producing the greatest ankle range of motion and locomotion speed amongst assistive devices. ConclusionsThis pre-clinical study found that the WKW could be the preferred assistive device for total unilateral offloading of diabetic foot ulcers as it reduced propulsive limb whole foot and forefoot plantar loading while retaining ankle range of motion and locomotion speed.

Gait Pathology in Subjects with Patellofemoral Instability: A Systematic Review.

Identifying potential gait deviations in patellofemoral instability (PI) can help with the development of effective rehabilitation strategies. The purpose of this systematic review was to examine whether there are specific gait alterations in subjects with PI. The present review followed the PRISMA guidelines and was initially registered at PROSPERO (CRD42021236765). The literature search was carried out in the databases of PubMed, the Cochrane library, Web of Science, ClinicalTrials.gov, and Medline. The search strategy resulted in the identification of seven relevant publications. Subjects with PI show decreased walking speed, stride length, and cadence. Some studies reported changes not only in knee kinematics and kinetics but also in hip and ankle kinematics and kinetics. There is evidence that most subjects with PI walk with a quadriceps avoidance gait and show increased genu valgum posture, but there is still great variability in the coping responses within individuals with PI. The discrepancy among the study results might underpin the fact that PI is a multifactorial problem, and subjects cope with the different underlying morphological as well as functional deficits using a variety of gait strategies, which makes the interpretation and understanding of the gait of subjects with PI a clinically challenging task.

Effectiveness of a wearable ankle-tubing gait training on ankle kinematics and motor control in hemiparetic stroke.

While excessive ankle plantarflexion is a common neuromuscular impairment resulting from insufficient coordination of selective ankle neuromotor control and kinematics during gait. We recently developed a wearable, inexpensive and sustainable wearable ankle-tubing gait training (WAGT) aimed at improving selective ankle motor control and kinematic coordination. We investigated the effects of WAGT on tibialis anterior (TA) and gastrocnemius (GCM) muscle electromyography (EMG) activity, TA: GCM muscle imbalance ratio, and ankle joint kinematics during gait in hemiparetic stroke patients. A convenience sample of 33 participants (15 non-stroke healthy adults and 18 hemiparetic stroke patients) underwent standardized electromyography and kinematic biomechanical tests under conventional gait training (CGT) and WAGT conditions. Analysis of variance (ANOVA) was used to determine the significance of differences in the TA: GCM muscle activation, muscle imbalance ratio, and ankle joint kinematics before and after the intervention and between the two groups at P < 0.05. WAGT was more effective than CGT in improving TA muscle activation (P < 0.01), TA: GCM muscle imbalance ratio (P < 0.01), and kinematic movement (P < 0.01) in adults with or without hemiparetic stroke. This study demonstrated that WAGT is relatively ease to design, wear and affordable to most clinicians and patients, hence it is suitable for many health care applications to correct gait-related movement abnormalities presented in the hemiparetic stroke patients.

The ankle kinematic reference of normal gait pattern in Thai adults.

ObjectiveThis study was aimed to establish the reference values of ankle kinematics and factors associated with ankle kinematics of healthy Thai adults.MethodsA prospective cohort was conducted among healthy volunteers aged between 18 and 40 years and evaluated gait analysis between 2016 and 2020. After applying the modified Halen Hayes marker set, participants were assigned to walk 8–10 rounds with their preferred speed. Demographic data i.e., age, gender and body mass index (BMI) and ankle kinematics (varus-valgus, dorsiflexion-plantar flexion, foot progression, and ankle rotation) using motion analysis software were recorded and analyzed.Results98 volunteers (60 females and 38 males) aged 28.6 ± 5.4 years with body mass index 21.2 ± 2.0 kg/m2 were included. The average ranges of ankle kinematics entire gait cycle were varus-valgus −1.62 to 3.17 degrees, dorsiflexion-plantar flexion 0.67 to 14.52 degrees, foot progression −21.73 to −8.47 degrees, and ankle rotation 5.22 to 9.74 degrees. The ankle kinematic data in this study population was significantly different from the normal values supplied by OrthoTrak software of the motion analysis program, especially more ankle internal rotation at mid-stance (5.22 vs. −12.10 degrees) and terminal stance (5.48 vs. −10.74 degrees) with P < 0.001. Foot progression significantly exhibited more external rotation for 1.5 degrees on the right compared to the left side, and for 5 degrees more in males than females. One increment in age was significantly correlated with ankle internal rotation at mid-swing (coefficient 0.21 degrees, P = 0.039). BMI had no statistical association with ankle kinematics. Statistical parametric mapping for full-time series of angle assessments showed significantly different foot progression at initial contact and terminal stance between sides, and our ankle kinematics significantly differed from the reference values of the motion analysis program in all planes (P < 0.05).ConclusionThe reference of ankle kinematics of Thai adults was established and differences between sides and the normal values of the motion analysis program were identified. Advanced age was associated with ankle internal rotation, and male gender was related to external foot progression. Further studies are needed to define all-age group reference values.

Ultrasound-Guided Anterior Talofibular Ligament Repair With Augmentation Can Restore Ankle Kinematics: A Cadaveric Biomechanical Study.

Background:Anterior talofibular ligament (ATFL) repair of the ankle is a common surgical procedure. Ultrasound (US)-guided anchor placement for ATFL repair can be performed anatomically and accurately. However, to our knowledge, no study has investigated ankle kinematics after US-guided ATFL repair.Hypothesis:US-guided ATFL repair with and without inferior extensor retinaculum (IER) augmentation will restore ankle kinematics.Study Design:Controlled laboratory study; Level of evidence, 4.Methods:A 6 degrees of freedom robotic testing system was used to apply multidirectional loads to fresh-frozen cadaveric ankles (N = 9). The following ankle states were evaluated: ATFL intact, ATFL deficient, combined ATFL repair and IER augmentation, and isolated US-guided ATFL repair. Three loading conditions (internal-external rotation torque, anterior-posterior load, and inversion-eversion torque) were applied at 4 ankle positions: 30° of plantarflexion, 15° of plantarflexion, 0° of plantarflexion, and 15° of dorsiflexion. The resulting kinematics were recorded and compared using a 1-way repeated-measures analysis of variance with the Benjamini-Hochberg test.Results:Anterior translation in response to an internal rotation torque significantly increased in the ATFL-deficient state compared with the ATFL-intact state at 30° and 15° of plantarflexion (P = .022 and .03, respectively). After the combined US-guided ATFL repair and augmentation, anterior translation was reduced significantly compared with the ATFL-deficient state at 30° and 15° of plantarflexion (P = .0012 and .005, respectively). Anterior translation was not significantly different for the isolated ATFL-repair state compared with the ATFL-deficient or ATFL-intact states at 30° and 15° of plantarflexion.Conclusion:Combined US-guided ATFL repair with augmentation of the IER reduced lateral ankle laxity due to ATFL deficiency. Isolated US-guided ATFL repair did not reduce laxity due to ATFL deficiency, nor did it increase instability compared with the intact ankle.Clinical Relevance:US-guided ATFL repair with IER augmentation is a minimally-invasive technique to reduce lateral ankle laxity due to ATFL deficiency. Isolated US-guided ATFL repair may be a viable option if accompanied by a period of immobilization.

Utility of Gait Biofeedback Training to Improve Walking Biomechanics in Patients With Chronic Ankle Instability: A Critically Appraised Topic.

Chronic ankle instability (CAI) is a condition that involves feelings of the ankle "giving way," pain, and decreased self-reported function. Individuals with CAI often demonstrate persistent biomechanical impairments during gait that are associated with repetitive lateral ankle sprains (LAS) and the development of early onset ankle posttraumatic osteoarthritis (OA). Traditional rehabilitation strategies have not successfully improved these reported aberrant gait biomechanics; thus, traditional rehabilitation may not effectively reduce the risk of recurrent LAS and ankle OA among individuals with CAI. Conversely, targeted gait training with biofeedback may be effective at decreasing the risk of recurring LAS and ankle OA if these rehabilitation strategies can promote individuals with CAI to develop a gait strategy that protects against subsequent LAS and ankle OA. Can targeted gait biofeedback interventions cause individuals with CAI to implement a walking gait pattern that is not associated with recurrent LAS and ankle OA? Five studies assessed gait biofeedback interventions targeting plantar pressure and/or ankle kinematics involving visual biofeedback (n = 3), auditory biofeedback (n = 1), and haptic biofeedback (n = 1). Plantar pressure was medially shifted during a single session while receiving biofeedback (n = 2), immediately after biofeedback (n = 1), and 5 minutes after receiving biofeedback (n = 1) in 3 studies. One study demonstrated reduced ankle inversion after 8 sessions of biofeedback training. One study did not substantially improve plantar pressure while receiving visual feedback. Targeted gait training strategies appear effective in acutely altering gait biomechanics in individuals with CAI while receiving, and immediately after, biofeedback has been removed. Long-term outcomes are not currently established for gait training strategies in those with CAI. Limited evidence (grade B) suggests that targeted gait biofeedback strategies can alter specific CAI gait biomechanics to a strategy not associated with recurrent LAS, and ankle OA immediately, and after, multiple sessions of gait training.

Lower limb kinematics during single leg landing in three directions in individuals with chronic ankle instability

ObjectivesTo compare the lower limb kinematics of participants with chronic ankle instability (CAI) and healthy participants during forward, lateral, and medial landings. DesignCross-sectional study. SettingLaboratory. ParticipantsEighteen athletes with CAI and 18 control athletes. Main outcome measuresHip, knee, and ankle joint kinematics during forward, lateral, and medial single-leg landings were compared between the groups using two-way ANOVA for discrete values and statistical parametric mapping two-sample t-tests for time-series data. ResultsThe CAI group had significantly greater ankle dorsiflexion than the control group (P ≤ 0.013), which was observed from the pre-initial contact (IC) for lateral and medial landings and post-IC for forward landing. The CAI group showed greater knee flexion than the control group from the IC for lateral landing and post-IC for forward landing (P ≤ 0.014). No significant differences in ankle inversion kinematics were found between the CAI and control groups. Lateral landing had a greater peak inversion angle and velocity than forward and medial landings (P < 0.001). Medial landing had a greater inversion velocity than forward landing (P < 0.001). ConclusionsThis study suggests that individuals with CAI show feedforward protective adaptations in the pre-landing phase for lateral and medial landings.

Females with knee osteoarthritis use a detrimental knee loading strategy when squatting

BackgroundThe purpose of this study was to identify sex differences in lower limb kinematics, kinetics, and muscle activation patterns between individuals with osteoarthritis and healthy controls during a two-legged squat. MethodThirty OA (15 females) and 30 healthy (15 females) participants performed three 2-legged squats. Sagittal and frontal plane hip, knee, and ankle kinematics and kinetics were calculated. Two-way ANOVAs (Sex X OA Status) were used to characterize differences in squatting strategies between sexes and between those with and without knee OA. ResultsA greater decrease in sagittal hip, knee, and ankle range of motion and knee joint power was observed in the OA participants compared to the healthy controls. Females with OA had significantly reduced hip and knee adduction angles compared to the healthy females and males with OA. Females also had decreased hip power, hip flexion, and hip adduction moments and knee adduction moments compared to their male counterparts, with the greatest deficits observed in the females with OA. Females with OA also had the highest magnitude of muscle activation for the quadriceps, hamstrings, and gastrocnemius throughout the squat, while males with OA showed increased activation of the vastus lateralis and medial gastrocnemius compared to the healthy males. ConclusionsOA significantly altered biomechanics and neuromuscular control during the squat, with males employing a hip-dominant strategy, allowing them to achieve a greater lower limb range of motion.

Poster 267: The Impact of Posterior Malleolar Fixation on Syndesmotic Stability

Objectives:Trans-syndesmotic fixation with suture buttons, posterior malleolar fixation (PMF) with screws and anterior inferior tibiofibular ligament (AITFL) augmentation with suture tape have all been suggested as potential treatments in the setting of a malleolar fracture. However, there is no consensus on the optimal treatment for small vs. large malleolar fractures. The purpose of this study was to determine which combination of: 1) posterior malleolar screw fixation, 2) syndesmotic fixation with suture button (SB), and 3) AITFL augmentation with suture tape (ST) best restored native tibio-fibular and ankle joint kinematics following a small and large posterior malleolar fracture.Methods:Twenty fresh frozen cadaveric lower leg specimens were divided into two groups and underwent biomechanical testing using a 6-degrees-of-freedom robotic arm in 7 states: 1) Native, 2) Syndesmosis Injury + Malleolar Fracture (Group 1: small fracture, Group 2: large fracture) 3) Screw fixation, 4) Screw + Suture Tape Augmentation, 5) Screw + Suture Tape Augmentation + Suture Button, 6) Suture Button + Suture Tape Augmentation, 7) Suture Button. Four biomechanical tests were performed at neutral and at 30 degrees of plantarflexion: 1) Internal Rotation, 2) External Rotation, 3) Lateral Drawer, 4) Posterior Drawer. The position of the tibia, fibula and talus were continuously recorded using a 5-camera motion capture system.Results:No differences were found in the efficacy of treatments between the small fracture and large fracture groups. In the external rotation test, screws with ST augmentation resulted in best stability of the fibula and ankle joint. In the internal rotation test, all repairs that included posterior malleolar screws stabilized the fibula and ankle. Posterior and lateral drawer of the foot resulted in only small differences between the intact and malleolar fracture states.Conclusions:Posterior malleolar fixation resulted in higher syndesmotic stability compared to trans-syndesmotic fixation with SBs. AITFL augmentation with ST provided additional external rotation stability when combined with screw fixation. Posterior malleolar screw fixation with AITFL augmentation using ST may be the preferred surgical method when treating patients with acute ankle injury involving an unstable syndesmosis injury and a posterior malleolar fragment.Figure 1.Sample of Syndesmosis Injury With Repair.Figure 2.Experimental Specimen Set-Up With the 6 D.O.F.Robotic Arm.

Paper 96: The Biomechanical Role of the Deltoid Ligament on Ankle Stability: Injury, Repair and Augmentation

Objectives:The deltoid ligament is frequently ruptured in association with ankle fractures and syndesmotic injuries. Despite the frequency of this ligamentous injury, surgical repair is not the current practice due to the belief that non-weightbearing during fracture recovery allows for adequate healing. However, conservative management has shown poor outcomes both acutely and over time with the development of arthritis. The contribution of the anterior and posterior bundles of the deltoid ligament to the stability of the ankle remains unknown, as does the effect of deltoid repair versus repair with augmentation.To determine the biomechanical role of the native anterior and posterior deltoid ligament in ankle stability and to determine the efficacy of simple suture vs augmented repair of each bundle. It was hypothesized that sectioning of the anterior and posterior deltoid ligaments would significantly increase ankle laxity in eversion, external rotation and anterior translation, repairing the anterior and posterior deltoid ligaments using suture anchors would significantly reduce ankle laxity compared to the sectioned states, and augmenting the repairs with an Internal Brace would further reduce ankle laxity compared to the suture anchor repair.Methods:Ten cadaveric ankles (50.9 mean age, male) were dissected free of soft tissue superficial to the medial ligamentous structures and mounted on a six-degrees-of-freedom robotic arm. The specimens underwent biomechanical testing in eight sequential states: 1) intact, 2) anterior deltoid cut, 3) anterior repair, 4) internal brace tibio-spring augmentation 5) internal brace tibio-calcaneal augmentation, 6) posterior deltoid cut, 7) posterior repair, 8) complete deltoid cut). Biomechanical testing consisted of three tests: 1) Anterior drawer 88 N, 2) Eversion 5 Nm, 3) External rotation 5 Nm, each run at 0° and 25° of plantarflexion under 100 N of joint compression. Anterior translation (mm) eversion (deg), external rotation (deg), were measured for each associated motion. A 1-factor random-intercepts linear mixed effect model was created for each test, and all pairwise comparisons were made between testing states, adjusting for multiple comparisons using Tukey’s method.Results:The complete deltoid cut state had significantly higher anterior translation, eversion, and external rotation at 0⁰ and 25⁰ of plantar flexion compared to all other states (+8.6mm ATT p=0.01-9, +34.1⁰ Eversion p=0.01-9, +14.7⁰ p=0.01-9 ER compared to native at 0⁰ plantar flexion, respectively). The anterior Deltoid cut showed a significant increase in eversion at 25⁰ of plantarflexion compared to the native state (+6.65⁰ P=0.0007). The anterior deltoid repair alone showed no significant decrease from the anterior deltoid cut, however both augmented anterior repairs showed significant decreases in eversion (-5.1⁰, p=0.023; -5.0, p=0.026, respectively). No other significant differences were observed between any states.Conclusions:The most important finding of this study was that the complete deltoid tear caused major ankle instability in anterior translation, external rotation and eversion. Therefore, deltoid repair is strongly recommended in the clinical setting of a complete tear. The anterior deltoid tear alone caused significant eversion instability at 25⁰ of plantarflexion, which was significantly reduced by the first augmented repair, the addition of a second augmentation showed no additional benefit over a single augmentation. Cutting the posterior deltoid in the setting of an augmented anterior repair showed no effect on ankle kinematics, therefore an augmented anterior repair can be seen a sufficient to stabilize a complete deltoid tear. Our findings suggest that surgeons may need to reconsider non-operative treatment on complete anterior deltoid injuries and that repair with augmentation offers superior stability.Figure 1.* is significantly different from all cut, # is significantly different from negative, $ is significantly different from anterior deltoid cutFigure 2.Location of augmented repairs.Figure 3.Setup.