Running-Related Injury Incidence: Does It Correlate with Kinematic Sub-groups of Runners? A Scoping Review.

BACKGROUND: Historically, kinematic measures have been compared across injured and non-injured groups of runners, failing to take into account variability in kinematic patterns that exist independent of injury, and resulting in false positives. Research led by gait patterns and not pre-defined injury status is called for, to better understand running-related injury (RRI) aetiology and within- and between-group variability. OBJECTIVES: Synthesise evidence for the existence of distinct kinematic sub-groups across a population of injured and healthy runners and assess between-group variability in kinematics, demographics and injury incidence. DATA SOURCES: Electronic database search: PubMed, Web of Science, Cochrane Central Register of Controlled Trials (Wiley), Embase, OVID, Scopus. ELIGIBILITY CRITERIA: Original, peer-reviewed, research articles, published from database start to August 2022 and limited to English language were searched for quantitative and mixed-methods full-text studies that clustered injured runners according to kinematic variables. RESULTS: Five studies (n = 690) were included in the review. All studies detected the presence of distinct kinematic sub-groups of runners through cluster analysis. Sub-groups were defined by multiple differences in hip, knee and foot kinematics. Sex, step rate and running speed also varied significantly between groups. Random injury dispersal across sub-groups suggests no strong evidence for an association between kinematic sub-groups and injury type or location. CONCLUSION: Sub-groups containing homogeneous gait patterns exist across healthy and injured populations of runners. It is likely that a single injury may be represented by multiple movement patterns, and therefore kinematics may not predict injury risk. Research to better understand the underlying causes of kinematic variability, and their associations with RRI, is warranted.

The effects of a two-week neuromuscular intervention on biopsychosocial variables in people with patellofemoral pain: an observational study.

Introduction: Patellofemoral pain (PFP) is common and predominately affects active populations. Altered biomechanics and psychosocial variables have been reported in people with PFP, but the effects of neuromuscular exercise on these variables is unknown. We aimed to investigate changes in biopsychosocial measures following a two-week neuromuscular intervention in people with PFP. Materials and Methods: We measured pain (visual analogue scale), function (Kujala), activity level (Tegner), psychological well-being (Orebro), lower-limb isometric strength (handheld dynamometry), three-dimensional (3D) lower limb kinematics, and surface electromyography (sEMG), in people with PFP. 3D lower-limb kinematics and sEMG were synchronously sampled during step-up, step-down, and overground running. All measures were repeated after participants had completed a two-week neuromuscular intervention consisting of three exercises completed once per day, five days per week. Results: 18 participants completed pre/post testing (60% females, mean age 30.6 years ±7.0, height 173.4cm ±10.4, mass 70.2kg ±12.4, symptom duration 39.0 months ±58.8), with three of 21 participants lost to follow-up. Across all clinical measures (muscle onsets, muscle activation and kinematics), the 95% bootstrapped confidence intervals (CI) of the mean difference contained the null hypothesis following the two-week neuromuscular intervention, indicating no significant differences. Conclusion: A two-week neuromuscular intervention did not change biomechanical or psychosocial measures in people with PFP. Interventions with a longer duration or greater load magnitude are required to fully evaluate the biopsychosocial mechanisms of effect for exercise in people with PFP.

Predicting the outcome of plantar heel pain in adults: a systematic review of prognostic factors.

BACKGROUND: Plantar Heel Pain (PHP) is a common disorder with many treatment pathways and is not self-limiting, hence prognostic information concerning recovery or recalcitrance is needed to guide practice. In this systematic review, we investigate which prognostic factors are associated with favourable or unfavourable PHP outcomes. METHODS: MEDLINE, Web of Science, EMBASE, Scopus and PubMed electronic bibliographic databases were searched for studies evaluating baseline patient characteristics associated with outcomes in prospective longitudinal cohorts or after specific interventions. Cohort, clinical prediction rule derivation and single arms of randomised controlled trials were included. Risk of bias was evaluated with method-specific tools and evidence certainty with GRADE. RESULTS: The review included five studies which evaluated 98 variables in 811 participants. Prognostic factors could be categorised as demographics, pain, physical and activity-related. Three factors including sex and bilateral symptoms (HR: 0.49[0.30-0.80], 0.33[0.15-0.72], respectively) were associated with a poor outcome in a single cohort study. The remaining four studies reported twenty factors associated with a favourable outcome following shockwave therapy, anti-pronation taping and orthoses. Heel spur (AUC = 0.88[0.82-0.93]), ankle plantar-flexor strength (Likelihood ratio (LR): 2.17[1.20-3.95]) and response to taping (LR = 2.17[1.19-3.90]) were the strongest factors predicting medium-term improvement. Overall, the study quality was low. A gap map analysis revealed an absence of research that included psychosocial factors. CONCLUSIONS: A limited number of biomedical factors predict favourable or unfavourable PHP outcomes. High quality, adequately powered, prospective studies are required to better understand PHP recovery and should evaluate the prognostic value of a wide range of variables, including psychosocial factors.

Self-reported bio-psycho-social factors partially distinguish patellar tendinopathy from other knee problems and explain patellar tendinopathy severity in jumping athletes: A case-control study.

OBJECTIVE: To determine what combinations of self-reported factors distinguish patellar tendinopathy (PT) from other knee problems, and explain PT severity variance. DESIGN: Case-control study. SETTING: Social media, private practice and National Health Service. PARTICIPANTS: An international sample of jumping athletes diagnosed with either PT (n = 132; 30.7 ± 8.9 years; 80 males; VISA-P = 61.6 ± 16.0) or another musculoskeletal knee condition (n = 89; 31.8 ± 9.9 years; 47 males; VISA-P = 62.9 ± 21.2) by a clinician in the last 6 months. MAIN OUTCOME MEASURES: We considered clinical diagnosis (case = having PT vs control = having other knee problems) as the dependent variable. Severity and sporting impact were defined by VISA-P and availability, respectively. RESULTS: A model comprising seven factors distinguished PT from other knee problems; training duration (OR = 1.10), sport type (OR = 2.31), injured side (OR = 2.28), pain onset (OR = 1.97), morning pain (OR = 1.89), condition acceptability (OR = 0.39) and swelling (OR = 0.37). Sports-specific function (OR = 1.02) and player level (OR = 4.11) explained sporting availability. 44% of PT severity variance was explained by quality of life (ß = 0.32), sports-specific function (ß = 0.38) and age (ß = -0.17). CONCLUSION: Sports-specific, biomedical and psychological factors partially distinguish PT from other knee problems. Availability is mainly explained by sports-specific factors, while psychosocial factors impact on severity. Adding sports-specific and bio-psycho-social factors into assessments could help better identification and management of jumping athletes with PT.

Neuromuscular joint function in knee osteoarthritis: A systematic review and meta-analysis.

BACKGROUND: Neuromuscular alterations are common in people with knee osteoarthritis (KOA). A comprehensive understanding of these alterations is important to enable targeted rehabilitation strategies. OBJECTIVES: This systematic review and meta-analysis aimed to comprehensively understand the neuromuscular alterations around the knee joint in people with KOA. METHODS: Moderate- and high-quality studies based on a modified version of the Downs and Black checklist, comparing neuromuscular function of peri­articular muscles between people with KOA and controls were retrieved from five databases from inception to October 2020. Outcomes included normalized isokinetic strength, muscle size, voluntary activation, cortical and spinal-reflex excitability, and torque-related outcomes. Data were pooled according to structural KOA severity with sensitivity analysis based on sex. Evidence levels are presented in evidence gap maps. RESULTS: A total of 7 high-quality and 22 moderate-quality studies were retained (1146 people with KOA and 1353 age- and sex-matched controls). Studies demonstrated quadriceps and hamstring strength deficits and increased hamstring-to-quadriceps strength ratios across KOA severities. Women presented lower quadriceps strength at early KOA (very limited evidence) and lower voluntary activation at end stage KOA (very limited evidence) as compared with controls, whereas men did not (moderate evidence). People with KOA also demonstrated lower quadriceps force control ability with no change in rapid force production (very limited evidence). Voluntary activation deficits for quadriceps were evident (moderate evidence), with no change in quadriceps cortical excitability (very limited evidence) or soleus spinal reflexes (very limited evidence). No muscle size change was demonstrated except for the vastus medialis (limited evidence). Evidence gaps were found for neural and torque-related measures and differences in hamstring, gastrocnemius, soleus, and popliteus. CONCLUSIONS: Neuromuscular deficits are evident across different structural KOA severities and are seen in muscle strength, voluntary activation, muscle size, and force control ability. Women may exhibit these alterations to a greater extent than men. PROSPERO REGISTRATION NUMBER: CRD42019160845.

Self-reported bio-psycho-social factors partially distinguish rotator cuff tendinopathy from other shoulder problems and explain shoulder severity: A case-control study.

OBJECTIVE: Examine how rotator cuff (RC) tendinopathy differed from other shoulder problems (OSP) by measuring a variety of self-reported bio-psycho-social factors, and establish which explain severity. METHODS: A validated online survey battery was used to collect self-reported biopsychosocial variables in an international population. Diagnostic group and severity were the dependent variables. Multiple logistic and linear regression analyses were utilised to generate explanatory models for group differences and severity after group comparison and univariate regression analysis. RESULTS: 82 people with RC tendinopathy (50 female, 42.8 ± 13.9 years) and 54 with OSP (33 female, 40.2 ± 14.1 years) were recruited. Both groups had comparable severity results (Shoulder Pain and Disability Index = 37.3 ± 24.5 vs. 33.7 ± 22.5). Seven factors individually differentiated RC tendinopathy from OSP. The multivariable model included 4 factors: activity effect on pain (OR(95%CI) = 2.24(1.02-4.90)), previous injury in the shoulder (OR(95% CI) = 0.30(0.13-0.69)), activity level (moderate OR(95% CI) = 3.97(1.29-12.18), high OR(95% CI) = 3.66(1.41-9.48)) and self-efficacy (OR(95%CI) = 1.12(1.02-1.22)) demonstrating acceptable accuracy. The second multivariable model for RC tendinopathy severity included one demographic, three psychological and two biomedical variables (ß(range) = 0.19-0.38) and explained 68% of the variance. CONCLUSION: Self-reported bio-psycho-social variables may be beneficial for further detailed clinical assessment as they partially distinguish RC tendinopathy from OSP, even when the groups have comparable overall pain and functional problems. Moreover, these variables were shown to be substantially associated with RC tendinopathy severity variance, implying that the clinical evaluation might be improved, perhaps by pre-consultation online data collection. The models should be validated in the future and considered alongside data from physical and imaging examinations.

Variables associated with successful outcome after anterior cruciate ligament reconstruction in recreational athletes: A prospective cohort study.

BACKGROUND: Anterior cruciate ligament (ACL) injury and subsequent reconstruction is common and has a profound effect on health-related quality of life. There is currently limited understanding as to which variables are associated with a successful outcome post-ACL reconstruction (ACLR) in recreational athletes. PURPOSE: Explore the association between both patient-reported and performance-based measures, and successful outcome, post-ACLR in recreational athletes. PROCEDURES: We sought to recruit recreational athletes within one month of a primary-ACLR for a prospective cohort study. A dichotomised patient specific functional scale of ≥9 points determined a successful outcome at nine-months post-operative. Secondary patient-reported and performance-based data were collected at baseline, three-, six-, and nine-months post-operative. The association between secondary data and the primary outcome was determined using binomial logistic regression, expressed using odds ratio (OR) and 95% confidence intervals (CI). MAIN RESULTS: 90 participants were recruited (males: 58, females: 32, mean age 32.8 years [±7.9], mean height 173.5 [±10.0], mean body mass 74.0 kg [±15.8]), 87 consented to baseline measures. 47 participants completed full data collection and 21 (45%) reported a successful outcome. Higher knee osteoarthritis outcome score (OR range 1.07-1.12) and anterior cruciate ligament quality of life (ACL-QoL) scores (OR range 1.06-1.10) were associated with a successful outcome post-ACLR at various timepoints. CONCLUSIONS: Patient-reported, rather than performance-based, measures were associated with successful outcome nine-months post-ACLR in recreational athletes. Both patient-reported and performance-based characteristics are advocated to guide optimal return to function in clinical practice.

Physical performance and perception of foot discomfort during a soccer-specific match simulation. A comparison of football boots.

Football boots are marketed with emphasis on a single key performance characteristic (e.g. speed). Little is known on how design parameters impact players' performance. This study investigated the impact of boot design on performance maintenance and perceived foot comfort during a 90-minute match simulation drill. Eleven male university football players tested two commercially available "sprint boots" known to generate significantly different plantar pressures (high=Boot H and low=Boot L) . Players completed a modified Soccer-specific Aerobic Field Test on a 3G pitch. Heart rate, rated perceived exertion and perceived foot discomfort were assessed for each 15-min interval. Power generation was assessed pre- and post-match simulation. A significantly higher mean heart rate was seen for Boot L in the 60th-75th and 75th-90th minute intervals (P = 0.017, P = 0.012 respectively). Perceived exertion did not differ between boots (P ≥ 0.302). Power generation significantly decreased in Boot H between pre- and post-match (P = 0.042). Both boots increased discomfort with significantly more plantar discomfort felt in the last 30 min in Boot H (75th min: P = 0.037; 90th min: P = 0.048). The results imply that a comfortable boot design may improve maintenance of performance during match-play.

Neuromuscular Function of the Knee Joint Following Knee Injuries: Does It Ever Get Back to Normal? A Systematic Review with Meta-Analyses.

BACKGROUND: Neuromuscular deficits are common following knee injuries and may contribute to early-onset post-traumatic osteoarthritis, likely mediated through quadriceps dysfunction. OBJECTIVE: To identify how peri-articular neuromuscular function changes over time after knee injury and surgery. DESIGN: Systematic review with meta-analyses. DATA SOURCES: PubMed, Web of Science, Embase, Scopus, CENTRAL (Trials). ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Moderate and high-quality studies comparing neuromuscular function of muscles crossing the knee joint between a knee-injured population (ligamentous, meniscal, osteochondral lesions) and healthy controls. Outcomes included normalized isokinetic strength, muscle size, voluntary activation, cortical and spinal-reflex excitability, and other torque related outcomes. RESULTS: A total of 46 studies of anterior cruciate ligament (ACL) and five of meniscal injury were included. For ACL injury, strength and voluntary activation deficits were evident (moderate to strong evidence). Cortical excitability was not affected at < 6 months (moderate evidence) but decreased at 24+ months (moderate evidence). Spinal-reflex excitability did not change at < 6 months (moderate evidence) but increased at 24+ months (strong evidence). We also found deficits in torque variability, rate of torque development, and electromechanical delay (very limited to moderate evidence). For meniscus injury, strength deficits were evident only in the short-term. No studies reported gastrocnemius, soleus or popliteus muscle outcomes for either injury. No studies were found for other ligamentous or chondral injuries. CONCLUSIONS: Neuromuscular deficits persist for years post-injury/surgery, though the majority of evidence is from ACL injured populations. Muscle strength deficits are accompanied by neural alterations and changes in control and timing of muscle force, but more studies are needed to fill the evidence gaps we have identified. Better characterisation and therapeutic strategies addressing these deficits could improve rehabilitation outcomes, and potentially prevent PTOA. TRIAL REGISTRATION NUMBER: PROSPERO CRD42019141850.