Hip Strength as a Predictor of Ankle Sprains in Male Soccer Players: A Prospective Study

Changes in Hip Isometric Strength of Female College Soccer Players After High-Workload Training Session

CONTEXT

The hip adductor and abductor muscles play vital roles as stabilizers in the lower-extremity. Their activation during soccer-specific actions is essential, but local muscular fatigue can hinder athletic performance and increase the risk of injury.

DESIGN

This study aimed to observe the variations in frontal plane hip strength in female college soccer players before and after a high-workload soccer-specific training session. Furthermore, the study sought to compare the relative changes in hip strength with the internal and external load measures obtained during that session.

METHODS

Twenty female college soccer players participated in a retrospective observational study. Isometric hip adductor and abductor strength were measured before and after a training session in the college spring season. Measurements were taken with a handheld dynamometer (MicroFET 2) while the players were supine. Global positioning system sensors (Catapult Vector S7), commonly worn by players during training sessions and competitive matches, were used to measure external and internal loads. Statistical analyses were performed using paired samples t test to assess hip adductor and abductor strength changes before and after the training session. Spearman rank was used to identify correlation coefficients between global positioning system data and isometric hip strength.

RESULTS

The findings revealed significant decreases in the strength of the right hip adduction (P = .012, -7% relative change), right abduction (P = .009, -7.6% relative change), and left abduction (P = .016, -4.9% relative change) after the training session. Furthermore, relative decreases in hip isometric adduction and abduction strength are related to the distance covered at high speeds.

CONCLUSION

The results of this study highlight that hip isometric adduction and abduction strength tend to decrease after exposure to high workloads during soccer-specific training.

Prognostic Values of Clinical and Anthropometric Characteristics in Lateral Ankle Sprain Following Physiotherapy

Lateral ankle sprain (LAS) is a common injury in sports and daily activities. The present study aimed to determine the prognostic value of clinical and anthropometric parameters in predicting LAS recovery after physiotherapy. Twenty-seven patients with acute LAS were included in this cohort study. First, prognostic factors and anthropometric variables were assessed, along with the time elapsed since the injury, pain score on a visual analogue scale (VAS), navicular drop, ankle range of motion (ROM), and ambulation status. Second, patients received physiotherapy, and their recovery status was assessed using the foot and ankle outcome score (FAOS) questionnaire immediately (first evaluation) and one month after physiotherapy (second evaluation). Univariate regression analysis and stepwise regression were used to evaluate the association between prognostic factors and outcome predictability. The results of this paper have shown that ambulation status was significantly correlated with all FAOS subscales in both the first and second evaluations, except for the FAOS-symptoms (FAOS-Sx) and FAOS-quality of life (FAOS-QOL) subscales in the first evaluation. The eversion ROM was significantly correlated with the FAOS-Sx and FAOS-Sports and Recreational activities (FAOS-Sport/Rec) subscales in the first evaluation. Additionally, age, height, and VAS were significantly correlated with FAOS-activity of daily living (FAOS-ADL) in the first evaluation, so this means that ambulation status is a valuable predictor of treatment success immediately and one month after physiotherapy intervention and compared to other FAOS subscales, the FAOS-QOL subscale is a more reliable predictor of the effectiveness of physiotherapy.

PREHAB FAI- Prehabilitation for patients undergoing arthroscopic hip surgery for Femoroacetabular Impingement Syndrome -Protocol for an assessor blinded randomised controlled feasibility study

BACKGROUND

The past decade has seen an exponential growth of minimally invasive surgical procedures. Procedures such as hip arthroscopy have rapidly grown and become the standard of care for patients with Femoroacetabular Impingement Syndrome (FAIS). Although, the results of such procedures are encouraging, a large proportion of patients do not achieve optimal outcomes due to chronicity and deconditioning as a result of delay in diagnosis and increased waiting times amongst other factors. In a recent systematic review and meta-analysis of randomised control trials, moderate certainty evidence supported prehabilitation over standard care in optimising several domains including muscle strength, pain and health related quality of life in patients undergoing orthopaedic surgical interventions. However, the role of prehabilitation in patients with FAI syndrome undergoing hip arthroscopy has received little attention.

AIM

To evaluate the feasibility, suitability, acceptability and safety of a prehabilitation programme for FAI to inform a future definitive randomised control trial to assess effectiveness.

METHODS

A systematically developed prehabilitation intervention based on a literature review and international consensus will be utilised in this study. A mixed methodology encompassing a two-arm randomised parallel study alongside an embedded qualitative component will be used to answer the study objectives. Patients will be recruited from a tertiary referral NHS centre for young adult hip pathology in the UK. Patient reported outcomes such as iHOT-12, Brief Pain Inventory Scale (Short form), Hospital Anxiety and Depression Scale and Patient Global Impression of Change score will be obtained alongside objective measurements such as Muscle Strength and Star Excursion Balance Test at various time points. Outcome measures will be obtained at baseline (prior to prehabilitation intervention), after prehabilitation before surgery, and at 6 weeks+/- 4 weeks and 6 months +/- 4 weeks (planned primary endpoint for definitive RCT) postoperatively when participants attend the research site for clinical care and remotely at 12 months +/- 4 weeks postoperatively. Mean change and 95% CI, and effect size of outcome measures will be used to determine the sample size for a future RCT. For the qualitative component, in depth face-to-face semi-structured interviews with physiotherapists and focus groups with participants will be conducted to assess the feasibility, suitability, and acceptability of the prehabilitation intervention using a predetermined success criteria. All qualitative data will be recorded, transcribed verbatim and thematically analysed.

DISCUSSION

This study will be first of its kind to evaluate a systematically developed prehabilitation intervention for patients with FAIS undergoing hip arthroscopy. This study will provide important preliminary data to inform feasibility of a definitive RCT in the future to evaluate effectiveness of a prehabilitation intervention.

TRIAL REGISTRATION

ISRCTN 15371248, 09/03/2023.

TRIAL PROTOCOL

Version 2.3, 26th June 2023.

Factors Associated With a Lateral Ankle Sprain in Young Female Soccer Players: A Prospective Cohort Study

Background

Previous studies have attempted to determine if certain risk factors can predict the occurrence of a lateral ankle sprain (LAS) in female soccer players. Unfortunately, there is limited evidence with regard to risk factors associated with an LAS in female soccer players.

Purpose

To identify intrinsic risk factors for an LAS among young female soccer players.

Study Design

Cohort study; Level of evidence, 2.

Methods

Participants were 161 young female soccer players in Japan who were evaluated for LAS risk factors during a preseason medical assessment. The assessment included anthropometric, joint laxity, joint range of motion, muscle flexibility, muscle strength, and balance measurements. Each athlete's history of LASs was also collected. The participants were monitored during a single-yearseason for LASs, as diagnosed by physicians.

Results

There were 26 instances of an LAS in 25 players (15.5%) during the season. Injured players were significantly more likely to have sustained a previous ankle sprain (P = .045) and demonstrated significantly worse balance than their peers without an LAS during the double- and single-leg balance tests (P = .008 for both). Athletes with lower hamstring-to-quadriceps muscle strength ratios were also significantly more likely to sustain an LAS (P = .02).

Conclusion

Poor balance, a low hamstring-to-quadriceps ratio, and a history of ankle sprains were associated with an increased risk of LASs in young female soccer players in the current study. These findings may be useful for developing a program to prevent LASs in this population.

Risk factors for acute ankle sprains in field-based, team contact sports: a systematic review of prospective etiological studies

OBJECTIVE

The aim of this systematic review was to identify prospectively measured ankle sprain risk factors in field-based team contact sports.

METHODS

Eight databases including SPORTDiscus, CINAHL Complete, MEDLINE (EBSCO), Education Source, Web of Science, Scopus, Embase, and Pubmed were searched using specific Boolean terms. A modified-CASP diagnostic test assessed the quality of the included studies. Extensive data extraction included but was not limited to injury definition, protocols for injury diagnosis and recording, and outcomes associated with ankle sprain.

RESULTS

4012 records were returned from the online search and 17 studies met the inclusion criteria for this review. Twelve different risk factors including anatomic alignment of the foot and ankle, joint laxity, height, mass, BMI (body mass index), age, ankle strength, hip strength, single leg landing performance (ground reaction force, pelvic internal rotation, and knee varus), and single leg reach were all found to be associated with ankle sprain incidence. Injury definitions and methods of diagnosis and recording varied across the 17 studies.

CONCLUSION

This review updates the literature on prospective risk factors for ankle sprain in a specific population rather than heterogeneous cohorts previously studied. From more than 20 categories of risk factors investigated for ankle sprain association across 17 studies in field-based team contact sports, 12 variables were found to be associated with increased incidence of ankle sprain. In order to reduce the risk of ankle sprain, BMI, ankle plantar and dorsiflexion strength, hip strength, and single leg landing performance should be factored in to athlete assessment and subsequent program design. More studies utilizing standardized definitions and methods of recording and reporting are needed. Future prospective etiological studies will allow strength and conditioning coaches, physiotherapists, and physicians to apply specific training principles to reduce the risk and occurrence of ankle sprain injuries.

The Trade Secret Taboo: Open Science Methods are Required to Improve Prediction Models in Sports Medicine and Performance

Clinical prediction models in sports medicine that utilize regression or machine learning techniques have become more widely published, used, and disseminated. However, these models are typically characterized by poor methodology and incomplete reporting, and an inadequate evaluation of performance, leading to unreliable predictions and weak clinical utility within their intended sport population. Before implementation in practice, models require a thorough evaluation. Strong replicable methods and transparency reporting allow practitioners and researchers to make independent judgments as to the model's validity, performance, clinical usefulness, and confidence it will do no harm. However, this is not reflected in the sports medicine literature. As shown in a recent systematic review of models for predicting sports injury models, most were typically characterized by poor methodology, incomplete reporting, and inadequate performance evaluation. Because of constraints imposed by data from individual teams, the development of accurate, reliable, and useful models is highly reliant on external validation. However, a barrier to collaboration is a desire to maintain a competitive advantage; a team's proprietary information is often perceived as high value, and so these 'trade secrets' are frequently guarded. These 'trade secrets' also apply to commercially available models, as developers are unwilling to share proprietary (and potentially profitable) development and validation information. In this Current Opinion, we: (1) argue that open science is essential for improving sport prediction models and (2) critically examine sport prediction models for open science practices.

Effect of Q-angle, lateral distal tibial angle and hip muscle torques on ankle injury

BACKGROUND

The ankle sprain is the most common ankle injury. Although the factors that increase the risk of ankle injury are included in the literature, the definitive evidence is controversial.

OBJECTIVE

The aim of our study was to examine whether Q-angle, lateral distal tibial angle (LDTA), and hip muscle torque are associated with ankle sprain.

METHODS

Thirty-six individuals who underwent an axial X-ray examination of the lower extremity following ankle sprain were included. The Q-angle and LDTA were measured on the axial knee X-rays on both sides. The isometric muscle strength was measured with a digital handheld dynamometer for the quadriceps femoris muscle, the gluteus medius muscle and the gluteus maximus muscle. Muscle torques were calculated by multiplying isometric muscle strength values with the distance to the joint center.

RESULTS

Discrimination analysis shows that the gluteus maximus (0.90), gluteus medius (0.49), quadriceps femoris muscle torques (0.34), and lateral distal tibial angle (0.43) were the factors that most contributed to ankle sprain. No significant relationship was found between the Q-angle and ankle sprain (p = 0.603). A strong relationship was found between LDTA, quadriceps femoris, gluteus medius and gluteus maximus muscle torques and ankle sprain (p = 0.014, p < 0.001, p = 0.011, p = 0.002, respectively).

CONCLUSIONS

In conclusion, the torques of the proximal muscle may be more related than the Q-angle to lateral ankle sprain injury. Individuals with high LDTA should also be carefully examined for the risk of ankle sprain.

Intrinsic Risk Factors for Ankle Sprain Differ Between Male and Female Athletes: A Systematic Review and Meta-Analysis

Background

Ankle sprains remain prevalent across most team sports. However, despite divergent ankle sprain injury rates in male and female athletes, little is known about potential sex-specific risk factors for ankle sprain.

Objective

To systematically investigate the sex-specific risk factors for ankle sprain.

Methods

Combinations of the key terms were entered into PubMed, Web of Science, Embase and Cochrane Library databases, and prospective studies reporting ankle sprain risk factors in males or females were included for meta-analysis.

Results

Sixteen studies were eligible for inclusion, for a total of 3636 athletes (735 female) and 576 ankle sprains (117 female). Out of 21 prognostic factors, previous ankle sprain injury (odds ratio = 2.74, P < .001), higher body mass index (SMD = 0.50, P < 0.001), higher weight (SMD = 0.24, P = 0.02), lower isometric hip abduction strength (SMD = − 0.52, P < 0.0001) and lower dynamic balance performance (SMD = − 0.48 to − 0.22, P < 0.001–0.04) were identified as risk factors in male athletes. In female athletes, out of 18 factors eligible for meta-analysis, only lower concentric dorsiflexion strength was identified as a risk factor (SMD = − 0.48, P = 0.005).

Conclusion

This meta-analysis provides novel evidence for different risk factor profiles for ankle sprain injuries between female and male athletes. Further studies, particularly in female athletes, are needed to strengthen the evidence.

The Effect of FIFA 11+ on the Isometric Strength and Running Ability of Young Soccer Players

Soccer is the world's game, and keeping athletes healthy while playing the game has often been a focus of study. There is a high occurrence of musculoskeletal injuries reported in soccer. FIFA 11+ was developed as an intervention to help prevent such injuries. FIFA 11+ has previously been studied for its efficacy as an injury prevention program, but not for its effect on sports performance in an adolescent population. The purpose of this study was to look at the effect of implementing the FIFA 11+ intervention on strength, speed, and agility. Twenty youth soccer players were randomly divided into an intervention group (INT) and a control group (CON). The intervention lasted for eight weeks and performance assessments were completed pre- and post-intervention. Post-test INT knee flexor strength was significantly higher than pre-test scores (p < 0.05). INT also demonstrated significantly higher hamstring to quadriceps strength ratio (H/Q) after the intervention (p < 0.05), while the CON H/Q did not change significantly. 30-m sprint performance of both groups improved from pre- to post-test (p < 0.05). Shuttle run performance was significantly improved in post-test scores for INT players (p < 0.05), but did not change significantly for the CON players. It is suggested that implementing FIFA 11+ before training in young soccer players can lead to performance benefits as well as injury prevention benefits.

Just How Confident Can We Be in Predicting Sports Injuries? A Systematic Review of the Methodological Conduct and Performance of Existing Musculoskeletal Injury Prediction Models in Sport

BACKGROUND

An increasing number of musculoskeletal injury prediction models are being developed and implemented in sports medicine. Prediction model quality needs to be evaluated so clinicians can be informed of their potential usefulness.

OBJECTIVE

To evaluate the methodological conduct and completeness of reporting of musculoskeletal injury prediction models in sport.

METHODS

A systematic review was performed from inception to June 2021. Studies were included if they: (1) predicted sport injury; (2) used regression, machine learning, or deep learning models; (3) were written in English; (4) were peer reviewed.

RESULTS

Thirty studies (204 models) were included; 60% of studies utilized only regression methods, 13% only machine learning, and 27% both regression and machine learning approaches. All studies developed a prediction model and no studies externally validated a prediction model. Two percent of models (7% of studies) were low risk of bias and 98% of models (93% of studies) were high or unclear risk of bias. Three studies (10%) performed an a priori sample size calculation; 14 (47%) performed internal validation. Nineteen studies (63%) reported discrimination and two (7%) reported calibration. Four studies (13%) reported model equations for statistical predictions and no machine learning studies reported code or hyperparameters.

CONCLUSION

Existing sport musculoskeletal injury prediction models were poorly developed and have a high risk of bias. No models could be recommended for use in practice. The majority of models were developed with small sample sizes, had inadequate assessment of model performance, and were poorly reported. To create clinically useful sports musculoskeletal injury prediction models, considerable improvements in methodology and reporting are urgently required.

Players with high physical fitness are at greater risk of injury in youth football

The aim of this study was to investigate physical fitness, football-specific skills, and their association with injury risk in youth football. Altogether 447 male and female players aged 9-14 years (median 12 years) participated in performance tests and prospective follow-up. The physical fitness tests included five-jump test for distance, 30-m sprint, football-specific figure of eight agility, countermovement jump, and Yo-Yo intermittent endurance test level 1. The football-specific skill tests included dribbling and passing tests. Injuries and exposure were registered during the 20-week follow-up. Our candidate risk factors were low/high level of physical fitness measured with a composite score of physical fitness tests and low/high level of football-specific skills measured with a composite score of dribbling and passing tests. Secondarily, we investigated performance in individual tests and their association with injury risk. During the follow-up, players reported 565 injuries (264 acute and 301 overuse injuries). High level of physical fitness was associated with increased rate of all injuries (age-, sex-, and mean team exposure-adjusted IRR: 1.28, 95% CI: 1.04-1.58). The level of football-specific skills had no influence on the overall injury rate. Burden of overuse injuries, but not acute injuries was significantly higher in most fit players compared with the players in the reference group (IRR: 2.09, 95% CI: 1.04-4.24). In conclusion, most fit players were at greater risk of sustaining injuries in youth competitive football.

Fatigue of hip abductor muscles implies neuromuscular and kinematic adaptations of the ankle during dynamic balance

OBJECTIVE

Determine whether hip abductor muscle fatigue influenced ankle kinematic and muscle activity during ankle-destabilized tasks.

DESIGN

Cross-sectional study.

METHODS

Twenty-six healthy, active participants performed two tests (Star Excursion Balance Test, SEBT; Weight Bearing Inversion Test, WBIT) for assessment of dynamic balance and ability to control inversion. Participants were equipped with an ankle-destabilizing sandal in inversion and eversion to perform both tests, which were completed before and after a fatiguing exercise of hip abductor muscles (up to 50% reduction in strength). Electromyographic activity of peroneus longus (PL) and brevis (PB), tibialis anterior, gastrocnemius lateralis (GastL) and gluteus medius (GlutM) muscles were recorded. In addition, ankle kinematics were recorded using an inertial measurement unit.

RESULTS

Hip abductor fatigue induced a significant decrease in SEBT scores in three directions (p < 0.01). During SEBT, ankle supination decreased by 3.2° in the anterior and posteromedial directions (p < 0.01). Muscle activity of GastL increased during achievement of three directions (p < 0.05) in response to hip abductor fatigue. In posteromedial direction, PL (p < 0.001) and GlutM (p < 0.01) activity increased with fatigue. During WBIT, inversion angular velocity was not impacted by fatigue while, PB and GastL activity increased after fatiguing exercise (p < 0.005).

CONCLUSION

A decrease in SEBT performance and EMG adaptations with proximal fatigue attest to the importance of the hip abductor muscle in dynamic postural control. This could have important implications in building injury prevention programs. Changes in ankle supination may reflect a protective strategy of the joint in response to hip fatigue.

The dominant leg is more likely to get injured in soccer players: systematic review and meta-analysis

In soccer (football), dominant limb kicking produces higher ball velocity and is used with greater frequency than the non-dominant limb. It is unclear whether limb dominance has an effect on injury incidence. The purpose of this systematic review with meta-analysis is to examine the relationship between limb dominance and soccer injuries. Studies were identified from four online databases according to PRISMA guidelines to identify studies of soccer players that reported lower extremity injuries by limb dominance. Relevant studies were assessed for inclusion and retained. Data from retained studies underwent meta-analyses to determine relative risk of dominant versus non-dominant limb injuries using random-effects models. Seventy-four studies were included, with 36 of them eligible for meta-analysis. For prospective lower extremity injury studies, soccer players demonstrated a 1.6 times greater risk of injury to the dominant limb (95% CI [1.3-1.8]). Grouped by injury location, hamstring (RR 1.3 [95% CI 1.1-1.4]) and hip/groin (RR 1.9 [95% CI 1.3-2.7]) injuries were more likely to occur to the dominant limb. Greater risk of injury was present in the dominant limb across playing levels (amateurs RR 2.6 [95% CI 2.1-3.2]; youths RR 1.5 [95% CI 1.26-1.67]; professionals RR 1.3 [95% CI 1.14-1.46]). Both males (RR 1.5 [95% CI 1.33-1.68)] and females (RR 1.5 [95% CI 1.14-1.89]) were more likely to sustain injuries to the dominant limb. Future studies investigating soccer injury should adjust for this confounding factor by using consistent methods for assigning limb dominance and tracking use of the dominant versus non-dominant limb.

Ankle Injuries in Soccer Players: A Narrative Review

Soccer is one of the most popular sport, with many describing it as the "king of sports." In recent years, increased global participation in soccer has led to an inevitable increase in injury rates, especially in the lower extremities. Consequently, there is an increase in the epidemiology of soccer injuries, both in professionals and amateur athletes. The cause of an injury is multifactorial and depends on psychosocial, predisposing, intrinsic, and extrinsic factors. Also, contact with another player and non-contact injuries seem to be the most widespread mechanisms of injuries. The most common injuries recorded in soccer are ankle sprains and hamstrings injuries. More specifically, many studies have shown a correlation between the previous injury in lower extremities, weakness of abductors muscle, and psychosocial factors with the ankle sprain. Additionally, according to study results, injuries in adult men, adolescent men, and women during a match are higher than injuries during training. This narrative review aims to record the epidemiology of ankle injuries, risk factors, and the relationship between circadian rhythm, sleep, and injuries.

Hip Abductor Muscle Strength Deficit as a Risk Factor for Inversion Ankle Sprain in Male College Soccer Players: A Prospective Cohort Study

Background:

Previous studies have attempted to determine whether certain risk factors can predict the occurrence of inversion ankle sprains in male collegiate soccer players. However, no consensus has been reached on the predictive risk factors of inversion ankle sprain in this population.

Purpose:

To identify risk factors for inversion ankle sprains among male collegiate soccer players.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

Included were 145 male collegiate soccer players in Japan who were assessed during a preseason medical checkup for potential risk factors of inversion ankle sprain. The preseason assessment included anthropometric measurements, joint laxity and flexibility, muscle flexibility, muscle strength, and balance ability, with a total of 33 variables. The participants were monitored during the 2019 season for inversion ankle sprains as diagnosed by physicians.

Results:

A total of 31 inversion ankle sprains in 31 players (21.4%) occurred during the season. Only the measured isometric hip abductor strength was significantly lower in injured players as compared with uninjured players. Logistic regression analysis revealed measured hip abductor muscle strength deficit as a significant risk factor for inversion ankle sprain (odds ratio, 0.978 [95% CI, 0.976-0.999]; P = .05).

Conclusion:

Hip abductor strength deficit was a risk factor for inversion ankle sprain in the study population. This finding could be useful for the prevention of inversion ankle sprains in male collegiate soccer players.

Greater knee varus angle and pelvic internal rotation after landing are predictive factors of a non-contact lateral ankle sprain

OBJECTIVES

This study aimed to clarify the kinematic, kinetic characteristics associated with lateral ankle sprain.

DESIGN

A 16-month prospective cohort study.

SETTING

Laboratory.

PARTICIPANTS

A total of 179 college athletes.

MAIN OUTCOME MEASURES

Joint kinematics, moment during single-leg landing tasks, and ankle laxity were measured. The attendance of each participating team, injury mechanism, existence of body contact, presence of orthosis, with or without medical diagnosis, and periods of absence were recorded.

RESULTS

Twenty-nine participants incurred lateral ankle sprain during non-contact motion. The Cox regression analysis revealed that greater knee varus peak angle (hazard ratio: 1.16 [95% confidence interval: 1.10-1.22], p < 0.001) and greater pelvic internal rotation peak angle toward the support leg were associated with lateral ankle sprain (hazard ratio: 1.08 [95% confidence interval: 1.02-1.15], p = 0.009). The cut-off values for each predictive factor were -0.17° (area under the curve = 0.89, p < 0.001) and 6.63° (area under the curve = 0.74, p < 0.001), respectively.

CONCLUSIONS

A greater knee varus peak angle and pelvic internal rotation peak angle after single-leg landing are predictive factors for lateral ankle sprain.

Ankle Stability and Movement Coordination Impairments: Lateral Ankle Ligament Sprains Revision 2021

This revised clinical practice guideline (CPG) addresses the distinct but related lower extremity impairments of those with a first-time lateral ankle sprain (LAS) and those with chronic ankle instability (CAI). Depending on many factors, impairments may continue following injury. While most individuals experience resolution of symptoms, complaints of instability may continue and are defined as CAI. The aims of the revision were to provide a concise summary of the contemporary evidence since publication of the original guideline and to develop new recommendations or revise previously published recommendations to support evidence-based practice. J Orthop Sports Phys Ther 2021;51(4):CPG1-CPG80. doi:10.2519/jospt.2021.0302.

Comparison between gymnasts and non-gymnasts in isometric strength of the lower limbs

Muscle asymmetries in gymnasts are common and can lead to injury. We aimed to determine differences in hip, knee, and ankle strength between female gymnasts and non-gymnasts, and secondly, to determine the effect of strength training intervention. Fifteen gymnasts (aged 11.19 ± 1.89 years) and 15 non-gymnasts (aged 10.92 ± 1.96 years) performed unilateral isometric maximal voluntary contractions of the hip (extensor, flexor, abductor, adductor, internal and external rotator), knee and ankle flexors and extensors on a dynamometer. Inter-limb asymmetries (ILAs) were compared across strength outcomes (MVC torque) and groups. ILAs was calculated based on the strength measurements. The gymnasts were retested after 8 weeks, during which the participants performed 5 weeks of regular training and 3 weeks of targeted strength training intervention. We found significant differences between groups in most observed hip strength parameters, but not in knee and ankle strength. The intervention did not significantly affect any parameter of ILAs. Gymnasts and non-gymnasts differ in hip strength parameters. A longer intervention program may decrease ILA parameters.

Intrarater Test-Retest Reliability of Hip Abduction, Internal Rotation, and External Rotation Strength Measurements in a Healthy Cohort Using a Handheld Dynamometer and a Portable Stabilization Device: A Pilot Study

Objective

To investigate the within-day and between-day test-retest reliability of hip abduction, internal rotation, and external rotation strength measurements taken using a portable device externally stabilizing a handheld dynamometer in healthy participants.

Design

Observational study.

Setting

Institute of Technology Carlow, Ireland, a third-level education institute.

Participants

Healthy participants (N=18; 11 male, 7 female) who participate in a field sport for more than 2 hours per week were recruited via convenience sampling.

Interventions

Not applicable.

Main Outcome Measures

Hip abduction, internal rotation, and external rotation peak force during a maximal voluntary isometric contraction (N). The 3 best values recorded for each movement for each day were used to analyze within-day and between-day test-retest reliability. Intraclass correlation coefficients (ICCs), coefficients of variance, standard error of measurement, and minimal detectable change statistics were also calculated.

Results

External fixation of a handheld dynamometer produced excellent test-retest reliability for within-day (ICC>0.934) and between-day (ICC>0.802) contexts.

Conclusions

Clinical measurements of hip strength can be performed reliably, efficiently, and cost effectively using the methods described. Furthermore, the use of external fixation eliminates the influence of tester strength on the handheld dynamometry measurements.

Association between lower extremity muscle strength and acute ankle injury in youth team-sports athletes

OBJECTIVES

To investigate lower extremity muscle strength as risk factor for an acute ankle injury in youth athletes.

DESIGN

Cohort study.

SETTING

Basketball and floorball clubs.

PARTICIPANTS

188 youth (≤21) male and 174 female athletes.

MAIN OUTCOME MEASURES

1RM leg press, maximal concentric isokinetic quadriceps and hamstrings as well as maximal isometric hip abductor strength were measured and athletes were followed for an acute ankle injury up to three years. Cox regression models were used in statistical analyses.

RESULTS

In males, greater 1RM leg press and maximal quadriceps strength increased the risk of any type of acute ankle injury (Hazard ratio [HR] for 1 SD increase, 1.63 [95% CI, 1.12-2.39] and 1.43 [95% CI, 1.01-2.01], respectively). In females, greater 1RM leg press and difference between legs in hip abduction strength increased the risk of acute non-contact ankle injury (HR for 1 SD increase, 1.44 [95% CI, 1.03-2.02] and 1.44 [95% CI, 1.03-2.00], respectively). However, ROC curve analyses showed AUC:s of 0.57-0.64 indicating "fail" to "poor" combined sensitivity and specifity of these tests.

CONCLUSION

Greater strength in both sexes along with asymmetry in hip abductor strength in females increased the risk of acute ankle injury.

Complexity of Gait Angle Measurements at the Ankle Joint During Midstance in Patients with Osteoarthritis

The evolution of rehabilitation treatments can be quantified through goniometric measurements. Thus, a video goniometer, and an app-based goniometry program can be both useful and a reliable method of obtaining a data base through which we can see if a certain rehabilitation treatment works out for our patients and during times such as the Covid-19 pandemic, a telemedicine approach can be done. Midstance is a sub-moment of the gait pattern, important in the stability of the lower limb, but that can also direct us towards a patient prone to falls. Osteoarthritis is a disease that causes high disability because of the cellular degradation that also affects normal gait. Four groups of subjects: subjects suffering from hip osteoarthritis, knee osteoarthritis, hip and knee osteoarthritis and control group, have been filmed and recorded their midstance joint range of motion in the Angles App. The dominant limb has been proven to have a more extended ankle in the hip osteoarthritis group, compared to knee osteoarthritis, hip and knee osteoarthritis or control group. Females have presented a more extended ankle, wearing high heels for a long period of time can be the cause of that. Subjects with knee osteoarthritis have presented a more flexed ankle in the dominant limb compared to the ones suffering from hip and knee osteoarthritis or control group. The ankle joint can also have its range of motion measured with a video goniometer, helping us compare results in between sessions of rehabilitation in osteoarthritic patients.

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

Background

Ankle instability can be problematic in an active population with multiple risk factors associated with recurrence.

Purpose

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.

Study Design

Quasiexperimental, Ex post facto.

Methods

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.

Results

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.

Conclusion

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.

Level Of Evidence

2b; Ex post facto.

Machine Learning to Predict Lower Extremity Musculoskeletal Injury Risk in Student Athletes

Injury rates in student athletes are high and often unpredictable. Injury risk factors are not agreed upon and often not validated. Here, we present a random-forest machine learning methodology for identifying the most significant injury risk factors and develop a model of lower extremity musculoskeletal injury risk in student athletes with physical performance metrics spanning joint strength measured with force transducers, postural stability measured using a force plate, and flexibility, measured with a goniometer, combined with previous injury metrics and athlete demographics. We tested our model in a population of 122 student athletes with performance metrics for the lower extremity musculoskeletal system and achieved an injury risk accuracy of 79% and identified significant injury risk factors, that could be used to increase accuracy of injury risk assessments, implement timely interventions, and decrease the number of career-ending or chronic injuries among student athletes.

Is the fibula positioned anteriorly in weight-bearing in individuals with chronic ankle instability? A case control study

Background: Clinically, a discrepancy of fibular position in relation to the tibia has been proposed as a factor in the persistence of chronic ankle instability (CAI). Previous studies have produced conflicting findings, perhaps due to varying radiological methods and measurement of participants in non-weight-bearing positions.Objectives: To compare normalized-fibular position in weight-bearing in individuals with CAI with healthy controls.Design: A weight-bearing lateral X-ray was taken of the affected ankle of 33 adults with CAI and 33 matched controls. The distance between the anterior edges of the distal fibula and tibia was recorded, and then normalized as a proportion of maximal tibial width. Normalized-fibular position was compared between groups using independent t-tests. Intra-class correlation coefficients (ICC_2,1) were calculated to determine reliability of measurements. A receiver-operating characteristic (ROC) curve was used to determine sensitivity, specificity, and a cutoff score to differentiate individuals with CAI from controls using normalized-fibular position.Results: Normalized fibular position was significantly different (CAI, 29.7 (6.6)%; healthy, 26.7 (4.8)%) between the groups. Measurement of intra-rater (0.99, 95%CI = 0.98 to 1.00) and inter-rater (0.98, 95%CI = 0.96 to 0.99) reliability were both excellent. The threshold normalized-fibular position was 27%, with a score more than 27% indicating a greater chance of being in the CAI group. Sensitivity was 69.7% and specificity was 54.5% for this threshold.Conclusion: A slightly anteriorly positioned fibula in relation to the tibia was observed in people with CAI. Specificity/sensitivity scores for normalized-fibular position indicate that it has little ability to predict CAI alone.

The Penn Vet Working Dog Center Fit to Work Program: A Formalized Method for Assessing and Developing Foundational Canine Physical Fitness

Fit to Work is a formalized working dog foundational physical fitness assessment and development program. The Penn Vet Working Dog Center developed this program to address the needs of working dog handlers, trainers, and programs for simple, effective, and efficient methods to develop and assess working dog physical fitness. Fit to Work focuses on the foundational fitness modalities of strength, stability, mobility, and proprioception. The Penn Vet Working Dog Center piloted and refined this program over 3 months in a closed population of 31 working dogs in training. Fit to Work consists of posture development and maintenance, warm-up and cool-down routines, training exercises, and assessment methods. To simplify implementation for dogs and personnel, the foundational training program incorporates a discrete number of exercises, standardized progression steps, defined criteria for progression, and a reduced emphasis on learned behaviors. Fit to Work also enables safe and progressive assessment of foundational fitness through a tiered and inexpensive process. Future research will focus on validation of training and assessment methods, development of assessment standards, and correlation of physical fitness with operational performance.

The predictive value of the multiple hop test for first-time noncontact lateral ankle sprains

The predictive value of the multiple hop test for first-time noncontact lateral ankle sprains.

BACKGROUND

Lateral ankle sprains (LAS) are very common sports injuries, cause high health care costs and are associated with postural control deficits. From a preventive point of view, clinicians should dispose valid field tests to identify athletes at risk for a LAS. The aim of this study is to evaluate the predictive value of the multiple hop test (MHT) for first-time noncontact LAS.

METHODS

Non-elite athletes (n = 232) performed the MHT at baseline. During a 12-month follow-up period, all noncontact LAS related to health care costs were recorded. Outcomes of the MHT (completion time, balance errors and perceived difficulty) between the injured and uninjured group were compared and odds ratios (OR) and relative risks (RR) were calculated using a logistic regression analysis.

RESULTS

Ten first-time noncontact LAS were recorded (4.3%). Injured athletes made significantly more change-in-support strategy (CSS) errors when compared to uninjured athletes (p = .04). The OR of the number of CSS errors was 1.14 (p = .03), the RR 4.1 (p = .04).

CONCLUSIONS

Athletes scoring > 12 CSS errors, have a four times increased risk for a first-time noncontact LAS. The MHT is a valid field test to identify athletes at risk for a first-time noncontact LAS.

Are Hip Physical Examination Findings Predictive of Future Lower-Body Injury Rates in Elite Adolescent Female Soccer Athletes at Minimum 5-Year Follow-Up?

CONTEXT

Although elite adolescent female soccer athletes have unique injury risk factors and management challenges, limited epidemiological data exist for this population.

OBJECTIVE

To describe lower-body injury patterns and to determine whether a screening hip physical examination is predictive of future injuries in elite adolescent female soccer athletes.

DESIGN

Prospective cohort study.

SETTING

One US premier soccer club.

PARTICIPANTS

One hundred seventy-seven female soccer athletes aged 10-18 years (mean [SD] 14.6 [1.8] y) completed a demographic questionnaire and screening hip physical examination that included range of motion and provocative tests.

INTERVENTIONS

At least 5 years after baseline screening, athletes completed an electronic follow-up injury survey. Injury was defined as pain that interfered with sporting activity.

MAIN OUTCOME MEASURES

In addition to descriptive analyses of athletes' injury profiles, associations between players' baseline demographics and subsequent injury profiles were evaluated using chi-square tests, and potential predictors of injury based on players' baseline hip examinations were evaluated using multivariable logistic regression.

RESULTS

Ninety-four of 177 athletes (53%) were contacted for follow-up, and 88/94 (93.6%) completed the survey. With mean follow-up of 91.9 (9.3) months (range 66-108 mo), 42/88 (47.7%) reported sustaining a new lower-body injury. The low back was the most common injury region (16/42, 38.1%). Almost half of all injured athletes (20/42, 47.6%) sustained overuse injuries, and 16/42 (38.1%) had an incomplete recovery. Higher body mass index and reaching menarche were associated with sustaining an injury (P = .03 and .04, respectively). Athletes' baseline hip examinations were not predictive of their subsequent rate of lower-body, lumbopelvic, overuse, or incomplete recovery injury (all P > .05).

CONCLUSIONS

Lower-body injuries were common in elite adolescent female soccer athletes, with over one third of injured athletes reporting permanent negative impact of the injury on their playing ability. Baseline hip physical examinations were not associated with future injury rate.