The Ankle-Joint Complex: A Kinesiologic Approach to Lateral Ankle Sprains

Lower leg muscle activation during the ebbets foot drills

Lateral ankle sprains (LAS) often lead to chronic ankle instability (CAI). The Ebbets foot drills were created to strengthen the lower leg muscles and reduce the risk of LAS. The current study aimed to explore the activation of the lower leg muscles during the Ebbets foot drills. Twenty-two (22) college students without LAS participated in the study. Surface electromyography (sEMG) of the tibialis anterior (TA), tibialis posterior (TP), and peroneus longus (PL) was collected during each of the Ebbets foot drills and a normal walking trial. The sEMG mean root mean square (RMS) was calculated for each walking and Ebbets foot drill trial duration. The mean RMS was higher during the Ebbets foot drills compared to normal walking for all muscles. The TA sEMG mean RMS was greater (4.0-68.3%, P = 0.001-0.023) during all the Ebbets foot drills than during the walking trial. The TP had greater mean RMS during the toe-in (50.4%, P < 0.001), toe-out (55.0%, P < 0.001), and backward walking (47.3%, P < 0.001) drills, than during the walking trial. The PL had greater mean RMS during all Ebbets foot drills (19.4-53.7%, P < 0.001) except for the heel walking and inversion drills. Ebbets foot drills higher muscle activity than regular walking, suggesting that the Ebbets foot drills could aid in the strengthening of the TA, TP, and PL muscles. These results build evidence on Ebbets' theory and indicate that these drills may be used to rehabilitate LAS and CAI.

Assistance force-line of exosuit affects ankle multidimensional motion: a theoretical and experimental study

BACKGROUND

The talocrural joint and the subtalar joint are the two major joints of the ankle-joint complex. The position and direction of the exosuit force line relative to these two joint axes can influence ankle motion. We aimed to understand the effects of different force-lines on ankle multidimensional motion.

METHODS

In this article, three assistance force line schemes for ankle exosuits were proposed: perpendicular to the talocrural joint axis (PT), intersecting with the subtalar joint axis (IS), and parallel to the triceps surae (PTS). A theoretical model was proposed to calculate the exosuit's assistance moment. Seven participants completed four experimental tests of ankle plantarflexion, including three passive motions assisted by the PT, PTS and IS schemes, and one active motion without exosuit assistance (Active).

RESULTS

The simulation results demonstrated that all three exosuits were able to produce significant moments of ankle plantarflexion. Among these, the PT scheme exhibited the highest moments in all dimensions, followed by the PTS and IS schemes. The experimental findings confirmed the effectiveness of all three exosuit schemes in assisting ankle plantarflexion. Additionally, as the assistive force lines approached the subtalar joint, there was a decrease in ankle motion assisted by the exosuits in non-plantarflexion directions, along with a reduction in the average distance of ankle angle curves relative to active ankle motion. Furthermore, the linear correlation coefficients between inversion and plantarflexion, adduction and plantarflexion, and adduction and inversion gradually converged toward active ankle plantarflexion motion.

CONCLUSIONS

Our research indicates that the position of the exosuit force line to the subtalar joint has a significant impact on ankle inversion and adduction. Among all three schemes, the IS, which has the closest distance to the subtalar joint axes, has the greatest kinematic similarity to active ankle plantarflexion and might be a better choice for ankle assistance and rehabilitation.

Causal Relationships Between Physical Activity and Arthrokinematic Integrity of the Ankle Joint-Foot Complex Across Normal and Pathological Phenomena: A Case-Control Analysis

Introduction Muscles, ligaments, tendons, bones, and cartilage undergo age-related changes, affecting the foot-ankle joint complex biomechanics in both genders. While international studies have extensively researched these dynamics, Indian studies are limited. Our study aims to fill this gap by analyzing the anthropometric and biomechanical function of the foot-ankle joint complex in normal individuals and those with painful pathologies at All India Institute of Medical Sciences (AIIMS) Rajkot's OPD. Methods In a two-year case-control study of the cross-sectional type conducted at AIIMS Rajkot's OPD, 158 patients with similar pain intensity on the Numeric Pain Rating Scale were examined. Anthropometric and biomechanical measurements were taken for both affected and non-affected foot and ankle joints. Cases comprised patients with foot and ankle joint pain, while controls were selected based on predefined criteria and were without such pain. Ethical approval was acquired from the Institutional Ethical Committee of AIIMS Rajkot. Results The sprain of the ankle joint and foot was the most common musculoskeletal pathology (65 out of 158 cases, i.e., 41.13%) affecting the ankle joint-foot complex. Patients involved in occupations requiring higher physical inactivity suffer more commonly from ankle joint-foot pathologies. The mean difference in the range of motion, i.e., dorsiflexion, plantar flexion, inversion, and eversion, between affected and non-affected feet was found to be lower in the patients who belonged to occupations involving low physical activity compared to those patients having occupations with high physical activity. Conclusion Reduced physical activity increases the stiffness and reduces the flexibility of the tendons, muscles, and ligaments of any joint (the ankle joint-foot complex in this study) and is associated with a higher incidence of musculoskeletal pathologies.

Lateral Ankle Joint Injuries in Indoor and Court Sports: A Systematic Video Analysis of 445 Nonconsecutive Case Series

BACKGROUND

Lateral ankle sprains are one of the most common injuries in indoor and court sports. Self-reports and case studies have indicated that these injuries occur via both contact and noncontact injury mechanisms typically because of excessive inversion in combination with plantarflexion and adduction of the foot. Video-based documentation of the injury mechanism exists, but the number of cases reported in the literature is limited.

PURPOSE

To retrieve and systematically analyze a large number of video-recorded lateral ankle injuries from indoor and court sports, as well as describe the injury mechanism, injury motion, and injury pattern across different sports.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 445 unique video-recorded lateral ankle sprain injuries were retrieved from indoor and court sports of broadcasted levels of competition. The videos were independently analyzed by 2 different reviewers. Outcomes included classification of the injury mechanism according to the International Olympic Committee consensus guidelines, primary and secondary motions of ankle joint distortion, and documentation of the fixation point (fulcrum) around which the foot rotates.

RESULTS

Overall, 298 (67%) injuries were direct contact, 113 (25%) were noncontact, and 32 (7%) were indirect contact incidents. Direct contact injuries were especially prevalent in basketball (76%), handball (80%), and volleyball (85%), while noncontact injuries dominated in tennis and badminton (96% vs 95% across both). Inversion (65%) and internal rotation (33%) were the primary distortion motions, with the lateral forefoot (53%) and lateral midfoot (40%) serving as the main fulcrums. Landing on another player's foot was the leading cause of injury (n = 246; 55%), primarily characterized by inversion (79%) around a midfoot fulcrum (54%). The noncontact and indirect landings on floor (n = 144; 33%) were primarily characterized by a distortion around a forefoot fulcrum (69%).

CONCLUSION

Two of 3 ankle sprains from online video platforms were direct contact injuries, with most involving landing on another player's foot. The distortion motion seems to be related to the injury mechanism and the fixation point between the foot and the floor. The injury mechanisms varied greatly between sports, and future studies should clearly differentiate and investigate the specific injury mechanisms.

The relationship between joint kinematic patterns during single-leg drop landing and perceived instability in individuals with chronic ankle instability

BACKGROUND

Perceived instability is a primary symptom among individuals with chronic ankle instability. However, the relationship between joint kinematics during landing remains unclear. Therefore, we investigated the relationships between landing kinematics and perceived instability in individuals with chronic ankle instability.

METHODS

In 32 individuals with chronic ankle instability, we recorded ankle, knee, and hip joint angles during a single-leg drop landing. Joint angle waveforms during 200 ms before and after initial contact were summarized into single values using two methods: peak joint angles and principal component scores via principal component analysis. Using Spearman's rank correlation coefficient (ρ), we examined the relationships of peak joint angles and principal component scores with the Cumberland Ankle Instability Tool score, with a lower score indicating a greater perceived instability (α = 0.05).

FINDINGS

The second principal component scores of ankle angle in the horizontal and sagittal planes significantly correlated with the Cumberland Ankle Instability Tool score (Horizontal: ρ = 0.507, P = 0.003; Sagittal: ρ = -0.359, P = 0.044). These scores indicated the differences in the magnitude of angles before and after landing. Significant correlations indicated a greater perceived instability correlated with smaller internal rotation and plantarflexion before landing and smaller external rotation and dorsiflexion after landing. In contrast, no peak joint angles correlated with the Cumberland Ankle Instability Tool score (P > 0.05).

INTERPRETATION

In individuals with chronic ankle instability, ankle movements during landing associated with perceived instability may be a protective strategy before landing and potentially cause ankle instability after landing.

Effects of Peroneus Brevis versus Peroneus Longus Muscle Training on Muscle Function in Chronic Ankle Instability: A Randomized Controlled Trial

Chronic ankle instability (CAI) is a common injury that can occur in daily life or sporting events. Injuries to the anterior talofibular, posterior talofibular, and calcaneofibular ligaments are common, and the core of rehabilitation training involves strengthening the peroneus muscle. Many studies on rehabilitation training have focused on strengthening the peroneus brevis muscle, and few studies have focused on specific training to strengthen the peroneus longus muscle. Therefore, this study aims to investigate changes in the symptoms and functions of patients by applying training to strengthen the peroneus longus and peroneus brevis muscles. Home-based training and mobile monitoring were utilized for 12 weeks, divided into peroneus brevis training (PBT) and peroneus longus training (PLT), in 52 adult males with CAI. Participation was voluntary, with enrollment done through a bulletin board, and intervention training allocation was randomly assigned and conducted in a double-blind manner. This study was registered as a trial protocol (KCT 0008478). Foot and ankle outcome scores (FAOS), isokinetic ankle strength tests, and Y-balance tests were performed before and after the intervention. Both PLT and PBT significantly improved in FAOS, inversion, and eversion at angular velocities of 30°/s and 120°/s and in the anterior and posterolateral directions of the Y-balance test (p < 0.05). Interaction effects by time and group were not significant for the FAOS (p > 0.05). However, PLT improved eversion muscle strength and muscle power to a greater degree, compared with PBT, in the anterior and posterolateral directions of the Y-balance test (p < 0.05). In conclusion, both PLT and PBT were effective for CAI patients; in addition, PLT had greater potential for improving strength and balance.

Lateral Ankle Ligaments: An Insight Into Their Functional Anatomy, Variations, and Surgical Importance

BACKGROUND

Ankle sprains are prevalent injuries leading to functional impairment. The lateral ankle ligament complex (LLC), comprising the anterior talofibular ligament (ATFL), posterior talofibular ligament (PTFL), and calcaneofibular ligament (CFL), is weak and prone to injury. The morphometric data of these ligaments are essential for orthopedic practices, including techniques like direct repair or ATFL reconstruction with autograft/allograft, which are limited in the literature. The present study aims to document the anatomy and morphometry of the LLC.

METHODS

Fifteen adult Indian-origin embalmed cadavers were selected for the study. Ankles with antemortem or postmortem injuries or previous surgical interventions were excluded from the study. After precise dissection of the ankle's anterior and lateral aspects as per Cunningham's dissection manual, ligaments were exposed. Length and width were measured using a digital vernier caliper. Morphological attributes such as shape, orientation, and inter-fiber angles were documented.

RESULTS

The most common shape in ATFL was a single band (53.33%). Inner ATFL fibers merged with the ankle joint capsule in 73.33%. ATFL mean length and width were 14 ± 2.4 mm and 7.6 ± 2.0 mm. The angle between the fibula's long axis and ATFL fibers was 107 ± 22°, and the angle between tibiotalar joint lines and parallel ATFL fibers was 30 ± 9.5°. A single band of CFL was predominant (73.33%). The mean length and width of CFL were 18.4 ± 3.9 mm and 5.2 ± 1.3 mm; the angle between the anterior fibula border's long axes and parallel CFL line was 131°. PTFL length was 20.9 ± 3.3 mm and width was 6.2 ± 1.4 mm. The mean length and width of the anterior inferior talofibular ligament (AiTFL) were 11.7 ± 2.6 mm and 9.5 ± 1.6 mm, and of the posterior inferior talofibular ligament (PiTFL) were 12.8 ± 2.1 mm and 10.4 ± 2 mm.

CONCLUSION

Comprehensive knowledge of these ligaments' anatomy and relationships is vital for clinical examination and ultrasonography. Understanding LLC details aids radiologists and orthopedic surgeons in graft selection, sizing, and precise anatomical structure placement during surgical reconstruction.

Ankle Sprain History Does Not Significantly Alter Single- and Dual-Task Spatiotemporal Gait Mechanics

CONTEXT

Single- and dual-task walking gait assessments have been used to identify persistent movement and cognitive dysfunction among athletes with concussions. However, it is unclear whether previous ankle sprain injuries confound these outcomes during baseline testing. The purpose of this study was to determine the effects of (1) ankle sprain history and (2) time since prior ankle sprain injury on single- and dual-task spatiotemporal gait outcomes and cognitive measures.

DESIGN

Cross-sectional study.

METHODS

We assessed 60 college Division-I athletes (31 with ankle sprain history; 13 females and 18 males, 19.3 [0.8] y; 29 with no ankle sprain history, 14 females and 15 males, 19.7 [0.9] y) who completed injury history forms and underwent concussion baseline testing. Athletes completed single- and dual-task gait assessments by walking back and forth along an 8-m walkway for 40 seconds. Athletes wore a smartphone with an associated mobile application on their lumbar spine to record spatiotemporal gait parameters and dual-task cognitive performance. Separate multivariate analyses of variance were used to assess the effects of ankle sprain injury history on spatiotemporal measures, gait variability, and cognitive performance. We performed a multivariate regression subanalysis on athletes who reported time since injury (n = 23) to assess temporal effects on gait and cognitive performance.

RESULTS

Athletes with and without a history of ankle sprains had comparable spatiotemporal and gait variability outcomes during single- (P = .42; P = .13) and dual-task (P = .75; P = .55) conditions. Additionally, ankle sprain injury history did not significantly influence cognitive performance (P = .35). Finally, time since ankle sprain did not significantly affect single- (P = .75) and dual-task gait (P = .69), nor cognitive performance (P = .19).

CONCLUSIONS

Ankle sprain injury history did not significantly alter spatiotemporal gait outcomes nor cognitive performance during this common clinical assessment. Future studies may consider including athletes with ankle sprain injury history during concussion assessments.

Minimally Invasive Reconstruction of the Ankle Lateral Ligament Complex in Chronic Ankle Instability: Clinical Outcomes, Return to Sport and Recurrence Rate at Minimum Follow up of 5 Years

Background: Chronic ankle instability is a common condition that develops after lateral ankle sprains. Many surgical techniques have been described in case of failure of conservative treatment. The purpose of this paper is to present the results in terms of clinical outcomes, return to sport and recurrence rate after reconstruction of the lateral ligament complex of the ankle with a minimally invasive approach at a minimum follow up of five years. Methods: This retrospective study involved forty-seven patients treated for chronic ankle instability from January 2013 to November 2017. The clinical outcomes were evaluated with the American Orthopedic Foot and Ankle Society ankle and hindfoot score (AOFAS score), the University of California–Los Angeles Rating Scale (UCLA Rating Scale), the Karlsson–Peterson ankle instability score and the Halasi scale at a mean follow up time of 80 months. Results: The mean age of the patients was 42 years (23–63). The mean VAS pain score decreased from 5.6 (2–9) pre-operatively to 0.7 (0–7) post-operatively. The mean UCLA Rating Scale score improved from 7.7 (4–8) before surgical treatment to 9.2 (6–10) afterwards. The AOFAS score increased from a pre-operative mean value of 66.5 (40–95) to a post-operative mean value of 94 (88–100) and the Halasi scale from a pre-injury mean value of 4.3 (2–8) to 4.5 post-operatively (2–8). The mean Karlsson–Peterson ankle instability score increased from 71 (40–90) pre-operatively to 87.9 (70–90) post-operatively. During this period of follow up, the procedure survival rate was 95.7%, with two cases of recurrence of ankle sprain post-operatively after twelve months in one case and forty months in the other case. Conclusions: The described technique of reconstruction of the anterior talofibular and calcaneofibular ligament with a minimally invasive approach with a semitendinosus autograft is a viable treatment option for chronic ankle instability and enables the majority of patients to regain their activity and sport level with a low recurrence rate at a mid-term follow up.

Rehabilitation of a lateral ankle reconstruction in a male professional football player - A narrative case report

OBJECTIVES

Lateral ankle sprains involving the ATFL and CFL are common injuries in football with a high recurrence rate. There is a lack of research to guide post-operative rehabilitation of football players following lateral ligament ankle reconstructive surgery. This narrative case report discusses the management of a lateral ligament reconstruction in a male professional football player.

METHODS

A 25-year-old professional footballer underwent a lateral ankle reconstruction following recurrent lateral ankle sprains leading to an unstable ankle.

RESULTS

Following 11-weeks of rehabilitation the player was cleared to return to full-contact training. The player competed in his first competitive match 13-weeks post-injury and completed a 6-month full-training block, without episodes of pain or instability.

CONCLUSION

This case report illustrates the rehabilitation process of a football player following a lateral ankle ligament reconstruction within a timeframe expected in elite sport.

Acute and Chronic Subtalar Joint Instability: Does It Really Exist?

Acute and chronic subtalar instability and commonly coexistent with other hindfoot pathology but can be difficult to diagnose. A high degree of clinical suspicion is required as most imaging modalities and clinical maneuvers are poor at detecting isolated subtalar instability. The initial treatment is similar to ankle instability, and a wide variety of operative interventions have been presented in the literature for persistent instability. Outcomes are variable and limited.

A Unique Physical Therapy Approach in a Complex Case of Pott's Fracture: A Case Report

The ankle joint is a complex joint that bears the human body's weight throughout daily activities. Unimalleolar, bimalleolar, and trimalleolar fractures are the three subgroups that make up the category of ankle fractures. Determining the risk-benefit tradeoffs between non-operative and surgical therapy still requires a thorough initial examination of the fracture pattern, soft tissue condition, and patient characteristics. Ankle fractures that are stable and well-aligned respond well to conservative therapy. Open reduction and internal fixation is the current gold standard of treatment for displaced and unstable fracture patterns, with historical data revealing good to outstanding outcomes for the majority of these patients. We present a case of a 19-year-old female sustaining a Pott's fracture following a road traffic accident. The overall treatment technique used included the overload principle, task-specific training, and an impairment-based strategy. The patient's impairments with regard to the range of motion, strength, edema, discomfort, wound healing, and functional limitations were handled by the therapist using exercises, manual therapy, and compressive cryotherapy. A clinically significant rehabilitation protocol for treating Pott's fracture is established in this case report.

Lower Extremity Somatosensory Function Throughout Concussion Recovery: A Prospective Cohort Study

OBJECTIVE

Balance impairments may suggest somatosensory disruption beyond concussion clinical recovery, but somatosensory subsystems have never been directly assessed. Our objective was to examine somatosensory function between individuals with a concussion and healthy matched-controls at acute (<7 days) and asymptomatic (<72 hours of being symptom-free) time points.

SETTING

Laboratory.

PARTICIPANTS

Participants with a concussion and matched controls ( n = 24; 58% male, age: 19.3 ± 1.1 years, mass: 70.3 ± 16.4 kg, height: 177.3 ± 12.7 cm).

DESIGN

Prospective cohort.

MAIN MEASURES

Somatosensory assessments on the dominant limb at both time points included: (1) plantar touch sensation threshold via Semmes-Weinstein monofilaments, (2) plantar pressure pain threshold via algometry, and (3) knee absolute passive joint repositioning (PJR) error via Biodex across 3 arcs (105°-75°, 30°-60°, 90°-45° knee-flexion). We used mixed-model analyses of variance, post hoc Tukey honestly significant difference t tests with mean difference, 95% CI, and Hedges' g effect sizes to examine outcomes.

RESULTS

Touch sensation had a group effect with the concussion cohort needing 0.95 grams of force (gf) more relative to controls (95% CI: 0.03 to 1.87; P = .043). No touch sensation interaction was present, but medium and large effects were observed for greater gf needed among the concussed cohort at the acute (1.11 gf; 95% CI: 0.17 to 2.05; g = 0.96) and asymptomatic time points (0.79 gf; 95% CI: -0.15 to 1.73; g = 0.73). No plantar pressure pain threshold effects were observed ( P ≥ .311), with negligible pressure difference magnitudes at the acute (0.26 pound force [lbf]/cm 2 ; 95% CI: -1.54 to 2.06; g = 0.13) and medium magnitudes at the asymptomatic time points (0.99 lbf/cm 2 ; 95% CI: -0.81 to 2.80; g = 0.42) for the concussed cohort needing more pressure to detect pain. The 30° to 60° PJR had a time effect, with asymptomatic time point having 3.12° better accuracy (95% CI: 1.23° to 5.02; P = .002). The concussed cohort had small-to-medium magnitude differences relative to controls at the acute time point for PJR during 105° to 75° (0.89°; g = 0.30) and 90° to 45° (0.62°; g = 0.17), but not 30° to 60° (-1.75°; g = -0.40).

CONCLUSIONS

Individuals with a concussion exhibited large effects for diminished plantar touch sensation and small to medium effects for inhibited plantar pressure pain sensation compared with controls, which may indicate altered somatosensory function. Negligible PJR differences suggest knee joint position sense is not altered post-concussion. Pre- and postconcussion examination is warranted to understand causal somatosensory mechanisms.

Mechanical and Sensorimotor Outcomes Associated With Talar Cartilage Deformation After Static Loading in Those With Chronic Ankle Instability

CONTEXT

Those with chronic ankle instability (CAI) demonstrate deleterious changes in talar cartilage composition, resulting in alterations of talar cartilage loading behavior. Common impairments associated with CAI may play a role in cartilage behavior in response to mechanical loading.

OBJECTIVE

To identify mechanical and sensorimotor outcomes that are linked with the magnitude of talar cartilage deformation after a static loading protocol in patients with and those without CAI.

DESIGN

Cross-sectional study.

SETTING

Laboratory setting.

PATIENTS OR OTHER PARTICIPANTS

Thirty individuals with CAI and 30 healthy individuals.

MAIN OUTCOME MEASURES(S)

After a 60-minute off-loading period, ultrasonographic images of the talar cartilage were acquired immediately before and after a 2-minute static loading protocol (single-legged stance). Talar cartilage images were obtained and manually segmented to enable calculation of medial, lateral, and overall average talar thickness. The percentage change, relative to the average baseline thickness, was used for further analysis. Mechanical (ankle joint laxity) and sensorimotor (static balance and Star Excursion Balance Test) outcomes were captured. Partial correlations were computed to determine associations between cartilage deformation magnitude and the mechanical and sensorimotor outcomes after accounting for body weight.

RESULTS

In the CAI group, greater inversion laxity was associated with greater overall (r = -0.42, P = .03) and medial (r = -0.48, P = .01) talar cartilage deformation after a 2-minute static loading protocol. Similarly, poorer medial-lateral static balance was linked with greater overall (r = 0.47, P = .01) and lateral (r = 0.50, P = .01) talar cartilage deformation. In the control group, shorter posterolateral Star Excursion Balance Test reach distance was associated with greater lateral cartilage deformation (r = 0.42, P = .03). No other significant associations were observed.

CONCLUSIONS

In those with CAI, inversion laxity and poor static postural control were moderately associated with greater talar cartilage deformation after a 2-minute static loading protocol. These results suggest that targeting mechanical instability and poor balance in those with CAI via intervention strategies may improve how the talar cartilage responds to static loading conditions.

Tertiary rehabilitation in acute ankle sprain caused by sports training

BACKGROUND

An ankle sprain is a common joint sprain in sports injury, which is closely related to its physiological position and anatomical characteristics, and may progress into chronic ankle instability after improper early treatment or premature exercise.

OBJECTIVE

To analyze the tertiary rehabilitation effect of acute lateral ankle sprain caused by sports training.

METHOD

Ninety-six athletes with acute lateral ankle sprain diagnosed from January 2019 to June 2020 were included and divided into the control group and the rehabilitation group using the random number table grouping method, with 48 cases in each group. The two groups received standardized treatment, and the rehabilitation group additionally received tertiary rehabilitation. The American Orthopedic Foot and Ankle Society (AOFAS ) scores, degree of ankle swelling, pain, and re-injury rate were compared between the two groups.

RESULTS

The AOFAS scores of the two groups increased after treatment (P< 0.05). The degree of swelling in both groups after treatment was improved (P< 0.05). The Visual Analogue Scale (VAS) scores in both groups declined two weeks after treatment, with lower results observed in the rehabilitation group The two groups showed similar results of the follow-up visit (P< 0.05).

CONCLUSION

Rehabilitation exercise on acute lateral ankle sprain effectively relieves ankle swelling and pain.

What have we learnt from quantitative case reports of acute lateral ankle sprains injuries and episodes of 'giving-way' of the ankle joint, and what shall we further investigate?

Lateral ankle sprains are a commonly incurred injury in sports. They have a high recurrence rate and can lead to the development of persistent injury associated symptoms. We performed a quantitative synthesis of published case reports documenting the kinematics of acute lateral ankle sprains and episodes of 'giving-way' of the ankle joint to provide a comprehensive description of the mechanisms. A systematic literature search was conducted to screen records within MEDLINE® and EMBASE®. Additional strategies included manual search of specific journals, as well as contacting researchers in relevant communities to retrieve unpublished data. Twenty-four cases were included in the quantitative synthesis, 11 from individual case reports and 13 from four separate case series. Two authors independently reviewed all the articles and extracted ankle joint kinematic data. Excessive ankle inversion was the most pronounced kinematic pattern observed across all included cases, with a mean peak inversion angle of 67.5° (range 2.0 to 142) and a mean peak inversion velocity of 974°/s (range 468 to 1752). This was followed by internal rotation and plantar flexion, respectively. A homogeneous linear function revealed a mean inversion velocity across all cases of 337°/s (range 117 to 1400; R² = 0.78; p < 0.0001).

Exosomes derived from platelet-rich plasma administration in site mediate cartilage protection in subtalar osteoarthritis

Subtalar osteoarthritis (STOA) is often secondary to chronic ankle sprains, which seriously affects the quality of life of patients. Due to its etiology and pathogenesis was not studied equivocally yet, there is currently a lack of effective conservative treatments. Although they have been used for tissue repair, platelet-rich plasma-derived exosomes (PRP-Exo) have the disadvantage of low retention and short-lived therapeutic effects. This study aimed to determine whether incorporation of PRP-Exo in thermosensitive hydrogel (Gel) increased their retention in the joint and thereby playing a therapeutic role on STOA due to chronic mechanical instability established by transecting lateral ligaments (anterior talofibular ligament (ATFL)/calcaneal fibular ligament (CFL)). PRP-Exo incorporated Gel (Exo-Gel) system, composed of Poloxamer-407 and 188 mixture-based thermoresponsive hydrogel matrix in an optimal ratio, was determined by its release ability of Exo and rheology of Gel response to different temperature. The biological activity of Exo-Gel was evaluated in vitro, and the therapeutic effect of Exo-Gel on STOA was evaluated in vivo. Exo released from Exo-Gel continuously for 28 days could promote the proliferation and migration of mouse bone mesenchymal stem cells (mBMSCs) and chondrocytes, at the same time enhance the chondrogenic differentiation of mBMSCs, and inhibit inflammation-induced chondrocyte degeneration. In vivo experiments confirmed that Exo-Gel increased the local retention of Exo, inhibited the apoptosis and hypertrophy of chondrocytes, enhanced their proliferation, and potentially played the role in stem cell recruitment to delay the development of STOA. Thus, Delivery of PRP-Exo incorporated in thermosensitive Gel provides a novel approach of cell-free therapy and has therapeutic effect on STOA.

Graphical Abstract

Changes in segment coordination variability and the impacts of the lower limb across running mileages in half marathons: Implications for running injuries

BACKGROUND

Segment coordination variability (CV) is a movement pattern associated with running-related injuries. It can also be adversely affected by a prolonged run. However, research on this topic is currently limited. The purpose of this study was to investigate the effects of a prolonged run on segment CV and vertical loading rates during a treadmill half marathon.

METHODS

Fifteen healthy runners ran a half marathon on an instrumental treadmill in a biomechanical laboratory. Synchronized kinematic and kinetic data were collected every 2 km (from 2 km until 20 km), and the data were processed by musculoskeletal modeling. Segment CVs were computed from the angle-angle plots of selected pelvis-thigh, thigh-shank, and shank-rearfoot couplings using a modified vector coding technique. The loading rate of vertical ground reaction force was also calculated. A one-way MANOVA with repeated measures was performed on each of the outcome variables to examine the main effect of running mileage.

RESULTS

Significant effects of running mileage were found on segment CVs (p ≤ 0.010) but not on loading rate (p = 0.881). Notably, during the early stance phase, the CV of pelvis frontal vs. thigh frontal was significantly increased at 20 km compared with the CV at 8 km (g = 0.59, p = 0.022). The CV of shank transverse vs. rearfoot frontal decreased from 2 km to 8 km (g = 0.30, p = 0.020) but then significantly increased at both 18 km (g = 0.05, p < 0.001) and 20 km (g = 0.36, p < 0.001).

CONCLUSION

At the early stance, runners maintained stable CVs on the sagittal plane, which could explain the unchanged loading rate throughout the half marathon. However, increased CVs on the frontal/transverse plane may be an early sign of fatigue and indicative of possible injury risk. Further studies are necessary for conclusive statements in this regard.

Reliability and usefulness of the single leg heel raise balance test in patients with chronic ankle instability

We aimed to analyze the differences in static (including conventional and modified [single-leg heel-raise balance]) and dynamic postural stability and muscle endurance between patients with chronic ankle instability (CAI) and healthy controls, and to determine the reliability and usefulness of the single-leg heel-raise balance test in patients with CAI. In total, 26 patients with CAI and 26 healthy controls were enrolled. Postural stability was assessed using a postural stabilometry system. Muscle endurance was measured in dorsiflexion and plantarflexion using an isokinetic device. Modified static postural stability (P < 0.001) and dynamic postural stability (P < 0.001) were significantly poorer in the affected ankles of patients with CAI than in the controls. Plantarflexion endurance was significantly lower in the affected ankles of the patients with CAI than in the controls (P = 0.023). Modified static postural stability significantly correlated with plantarflexion endurance in both groups (CAI group: r = - 0.470, P = 0.015; healthy controls group: r = - 0.413, P = 0.036). Plantarflexion endurance was a significant risk factor for modified static postural stability in both the CAI group (R² = 0.221, P = 0.015) and healthy controls (R² = 0.170, P = 0.036). Given the reliability of the modified static postural stability test, clinicians and therapists should consider using it to assess improvements in postural stability and muscle endurance in patients with CAI before and after rehabilitation.

A mouse model of ankle-subtalar joint complex instability induced post-traumatic osteoarthritis

BACKGROUND

Ankle-subtalar joint complex instability is not uncommonly presented in the clinic, but symptoms and signs similar to other conditions can easily lead to its misdiagnosis. Due to the lack of appropriate animal models, research on ankle-subtalar joint complex instability is limited. The aims of the present study were to establish an animal model of ankle-subtalar joint complex instability in mice and to explore its relationship with post-traumatic osteoarthritis (PTOA).

METHODS

Twenty-one male C57BL/6J mice were randomly divided into three groups: SHAM group (sham surgery group), transected cervical ligament + anterior talofibular ligament (CL+ATFL) group, and transected cervical ligament + deltoid ligament (CL+DL) group. Two weeks after surgery, all mice underwent cage running training. Balance beam and gait tests were used to evaluate the changes in self-movement in the mice after ankle-subtalar ligament injury. Micro-CT and histological staining were used to evaluate the progress of PTOA.

RESULTS

Compared with the SHAM group, balance and gait were affected in the ligament transection group. Twelve weeks after surgery, the time required to cross the balance beam in the CL+ATFL group was 35.1% longer and the mice slipped 3.6-fold more often than before surgery, and the mean step length on the right side was 7.2% smaller than that in the SHAM group. The time required to cross the balance beam in the CL+DL group was 32.1% longer and the mice slipped 3-fold more often than prior to surgery, and the average step length on the right side was 5.6% smaller than that in the SHAM group. CT images indicated that 28.6% of the mice in the CL+DL group displayed dislocation of the talus. Tissue staining suggested that articular cartilage degeneration occurred in mice with ligament transection 12 weeks after surgery.

CONCLUSIONS

Transected mice in the CL+ATFL and CL+DL groups displayed mechanical instability of the ankle-subtalar joint complex, and some mice in the CL+DL group also suffered from talus dislocation due to ligament injury leading to loss of stability of the bone structure. In addition, as time progressed, the articular cartilage displayed degenerative changes, which affected the ability of animals to move normally.

Serial Within-Session Improvements in Ankle Dorsiflexion During Clinical Interventions Including Mobilization-With-Movement and A Novel Manipulation Intervention - A Case Series

BACKGROUND

Persisting reductions in ankle dorsiflexion range of motion are commonly encountered clinically and seen to be associated with adverse outcomes after ankle and other lower extremity injuries. Accordingly improving identified deficits is a common goal for rehabilitation; however, little data exists documenting any improvement related to interventions in these patients.

PURPOSE

To document the change in dorsiflexion range of motion after stretching and mobilization-with-movement and exercise and a novel manipulation intervention in a population of injured athletes.

DESIGN

Case series in 38 consecutive injured athletes with persisting reductions in ankle dorsiflexion range of motion (42 "stiff" ankles, 34 uninjured) in an outpatient sports physiotherapy clinic.

METHOD

During a single treatment session, two baseline measurements of weight-bearing dorsiflexion were taken at the start of the session to establish reliability and minimum detectable change, and then the same measures were performed after stretching and a mobilization-with-movement intervention, and again after clinical exercise and a novel manipulation which was applied on both ankles.

RESULTS

Excellent reliability was demonstrated (ICC2,1>0.93, MDC=3.5°) for the dorsiflexion measure. Statistically significant (p<0.01), but clinically meaningless improvements were seen after stretching and the mobilization-with-movement intervention on the injured and uninjured legs (1.9° and 1.4° respectively) with greater improvements seen after exercise and the subsequent manipulation (6.9° and 4.7°).

CONCLUSIONS

The relatively simple clinical exercise and manipulation intervention program was associated improvement in dorsiflexion range of motion in this cohort with persisting ankle stiffness. The interventions described largely restored range of motion consistent with baseline levels of the uninjured ankles. Improvements were also seen in the uninjured ankles following intervention.

A review of the role of lower-leg strength measurements in ankle sprain and chronic ankle instability populations

Lower-leg strength training has been a cornerstone of ankle sprain and chronic ankle instability (CAI) rehabilitation and an important consideration for return-to-play in athletes with ankle injuries. The purpose of this literature review is to offer a contemporary, evidence-based overview of the role of ankle strength measurements as they relate to acute ankle sprain rehabilitation and those who have developed CAI. A comprehensive 20-year scan of the relevant research was conducted to assist us in providing this important update for clinicians and biomechanists working with patients and subjects with acute and chronic ankle sprains. While variability exists with measurement devices and methodology, strength assessment remains a critical component of ankle sprain and CAI treatment schemes. Helpful tips on obtaining and processing the most accurate strength assessments for lower-leg musculature are presented.

Principles and guidelines in the management of ankle fractures in adults

Ankle fractures are common injuries that have many physical and psychosocial complications. As a result, it is important to be aware of how these patients present and are managed perioperatively. Detailed guidelines from NICE and the British Orthopaedic Association have been produced on this topic, including recent developments such as the decision to weight-bear early after surgery and the use of virtual fracture clinics. This article provides an overview of the key perioperative factors that need to be considered in cases of ankle fracture and the relevant clinical guidelines.

An inconspicuous stabilizer of the subtalar joint: MR arthrographic anatomy of the posterior talocalcaneal ligament

OBJECTIVE

The main function of the posterior talocalcaneal ligament (PTL) is to stabilize the posterior subtalar joint in the ankle. PTL is a potential source of pain in chronic subtalar instability. Our knowledge of the anatomy and function of PTL is limited and there are not many studies regarding its morphology. The aim of this study is to provide detailed information about imaging anatomy and morphology of PTL.

MATERIALS AND METHODS

This retrospective study included 197 ankle images of 184 patients (13 bilateral) obtained from MR arthrography (MRA) and conventional MRI between 2012 and 2019. The incidence of PTL was evaluated using both methods. The location of the ligament to the calcaneus, shape, and intraarticular extension was determined by MRA. In addition, thickness and lengths were measured in millimeters, and the presence of os trigonum, contrast agent extravasation into adjacent anatomical structures, was evaluated. The upper surface of the calcaneus was divided into nine regions in the axial view and three regions in the sagittal view.

RESULTS

The incidence of PTL was 65.5% (n = 129). In axial view, the most common calcaneal attachment was in the 5th zone. The ligament was mostly fan-shaped (n = 104) and the extraarticular course was 87%. The average length was 15.9 mm and the average thickness was 1.1 mm. There were os trigonum in 18 cases.

CONCLUSION

Having knowledge of the morphology and variations of PTL and defining its relationship with adjacent anatomical structures can help evaluate subtalar instability.