How robust are clinical trials in primary and secondary ankle sprain prevention?

OBJECTIVES: Determine the statistical stability of RCTs examining primary and secondary prevention of ankle sprains. METHODS: Databases were searched to August 2023. We included parallel design RCTs, using conservative interventions for preventing ankle sprain, reporting dichotomous injury event outcomes. Statistical stability was quantified using Fragility Index (FI) and Fragility Quotient (FQ). Subgroup analyses were undertaken to test if FI varied based on by study objective, original approach to analysis (frequency vs time to event), follow-up duration, and pre-registration. RESULTS: 3559 studies were screened with 45 RCTs included. The median number of events required to change the statistical significance (FI) was 4 (IQR 1-6). FI was similar regardless of study objective, original analysis, follow-up duration, and pre-registration status. Median (IQR) FQ was 0.015 (0.005-0.046), therefore reversing events <2 patients/100 would alter significance. In 80% of studies the number of patients lost to follow-up was greater than the FI. CONCLUSION: RCTs informing primary and secondary prevention of ankle sprain are fragile. Only a small percentage of outcome event reversals would reverse study significance, and this is often exceeded by the number of drop outs. Robust reporting of dichotomous outcomes requires the use P values and key metrics such as FI or FQ.

Recurrent injury patterns in adolescent rugby.

OBJECTIVES: To establish patterns of subsequent injury in U18 rugby, to quantify the burden of within season injury recurrence. DESIGN: Secondary analysis of prospective data. SETTING: 28 Schools in Ireland. PARTICIPANTS: 825 male rugby players (aged 15-18 years). MAIN OUTCOME MEASURES: Subsequent injuries were classified as: new, local or recurrent (same site and type as index injury). All recurrent injuries were sub-grouped by body part and diagnosis. Burden was based on frequency, days lost and injury proportion ratios. RESULTS: A total of 426 injuries were eligible for analysis, of which, 121 were subsequent injuries. The majority of subsequent injuries involved a different body part than their index injury. There were n = 23 cases of within season recurrence. 78% of recurrences occurred within 2 months of return to play. Recurrent injuries comprised 5% of all injuries and their cumulative time loss was 1073 days. Recurrent injury to the ankle ligaments, lumbar muscles and concussions carried the greatest burden. CONCLUSION: The burden of recurrent injury in U18 rugby is lower than in the professional game. However, this population could benefit from targeted secondary prevention efforts including reconsideration of return-to-play protocols for ankle sprain, lumbar muscles and potentially concussion.

Biotensegrity and myofascial chains: A global approach to an integrated kinetic chain.

Human movement is a complex orchestration of events involving many different body systems. Understanding how these systems interact during musculoskeletal movements can directly inform a variety of research fields including: injury etiology, injury prevention and therapeutic exercise prescription. Traditionally scientists have examined human movement through a reductionist lens whereby movements are broken down and observed in isolation. The process of reductionism fails to capture the interconnected complexities and the dynamic interactions found within complex systems such as human movement. An emerging idea is that human movement may be better understood using a holistic philosophy. In this regard, the properties of a given system cannot be determined or explained by its components alone, rather, it is the complexity of the system as a whole, that determines how the individual component parts behave. This paper hypothesizes that human movement can be better understood through holism; and provides available observational evidence in musculoskeletal science, which help to frame human movement as a globally interconnected complex system. Central to this, is biotensegrity, a concept where the bones of the skeletal system are postulated to be held together by the resting muscle tone of numerous viscoelastic muscular chains in a tension dependent manner. The design of a biotensegrity system suggests that when human movement occurs, the entire musculoskeletal system constantly adjusts during this movement causing global patterns to occur. This idea further supported by recent anatomical evidence suggesting that the muscles of the human body can no longer by viewed as independent anatomical structures that simply connect one bone to another bone. Rather, the body consists of numerous muscles connected in series, and end to end, which span the entire musculoskeletal system, creating long polyarticular viscoelastic myofascial muscle chains. Although theoretical, the concept of the human body being connected by these muscular chains, within a biotensegrity design, could be a potential underpinning theory for analyzing human movement in a more holistic manner. Indeed, preliminary research has now used the concept of myofascial pathways to enhance musculoskeletal examination, and provides a vivid example of how range of motion at a peripheral joint, is dependent upon the positioning of the entire body, offering supportive evidence that the body's kinetic chain is globally interconnected. Theoretical models that introduce a complex systems approach should be welcomed by the movement science field in an attempt to help explain clinical questions that have been resistant to a linear model.

RISUS study: Rugby Injury Surveillance in Ulster Schools.

OBJECTIVE: To examine injury patterns in adolescent rugby players and determine factors associated with injury risk. DESIGN: Prospective injury surveillance study. SETTING: N=28 Grammar Schools in Ulster, Ireland (2014-2015 playing season). PARTICIPANTS: 825 adolescent rugby players, across in 28 school first XV rugby squads; mean age 16.9 years. MAIN OUTCOME MEASURES: Injuries were classified by body part and diagnosis, and injury incidence using injuries per 1000 match hours of exposure. HRs for injury were calculated through Cox proportional hazard regression after correction for influential covariates. RESULTS: A total of n=426 injuries were reported across the playing season. Over 50% of injuries occurred in the tackle situation or during collisions (270/426), with few reported during set plays. The 3 most common injury sites were head/face (n=102, 23.9%), clavicle/shoulder (n=65, 15.3%) and the knee (n=56, 13.1%). Sprain (n=133, 31.2%), concussion (n=81, 19%) and muscle injury (n=65, 15.3%) were the most common diagnoses. Injury incidence is calculated at 29.06 injuries per 1000 match hours. There were no catastrophic injuries. A large percentage of injuries (208/424) resulted in absence from play for more than 28 days. Concussion carried the most significant time out from play (n=33; 15.9%), followed by dislocations of the shoulder (n=22; 10.6%), knee sprains (n=19, 9.1%), ankle sprains (n=14, 6.7%), hand/finger/thumb (n=11; 5.3%). 36.8% of participants in the study (304/825) suffered at least one injury during the playing season. Multivariate models found higher risk of injury (adjusted HR (AHR); 95% CI) with: higher age (AHR 1.45; 1.14 to 1.83), heavier weight (AHR 1.32; 1.04 to 1.69), playing representative rugby (AHR 1.42; 1.06 to 1.90) and undertaking regular strength training (AHR 1.65; 1.11 to 2.46). Playing for a lower ranked team (AHR 0.67; 0.49 to 0.90) and wearing a mouthguard (AHR 0.70; 0.54 to 0.92) were associated with lower risk of injury. CONCLUSIONS: There was a high incidence of severe injuries, with concussion, ankle and knee ligament injuries and upper limb fractures/dislocations causing greatest time loss. Players were compliant with current graduated return-to-play regulations following concussion. Physical stature and levels of competition were important risk factors and there was limited evidence for protective equipment.

Cooling an acute muscle injury: can basic scientific theory translate into the clinical setting?

Ice is commonly used after acute muscle strains but there are no clinical studies of its effectiveness. By comparison, there are a number of basic scientific studies on animals which show that applying ice after muscle injury has a consistent effect on a number of important cellular and physiological events relating to recovery. Some of these effects may be temperature dependant; most animal studies induce significant reductions in muscle temperature at the injury site. The aim of this short report was to consider the cooling magnitudes likely in human models of muscle injury and to discuss its relevance to the clinical setting. Current best evidence shows that muscle temperature reductions in humans are moderate in comparison to most animal models, limiting direct translation to the clinical setting. Further important clinical questions arise when we consider the heterogenous nature of muscle injury in terms of injury type, depth and insulating adipose thickness. Contrary to current practice, it is unlikely that a 'panacea' cooling dose or duration exists in the clinical setting. Clinicians should consider that in extreme circumstances of muscle strain (eg, deep injury with high levels of adipose thickness around the injury site), the clinical effectiveness of cooling may be significantly reduced.

Cryotherapy for acute ankle sprains: a randomised controlled study of two different icing protocols.

BACKGROUND: The use of cryotherapy in the management of acute soft tissue injury is largely based on anecdotal evidence. Preliminary evidence suggests that intermittent cryotherapy applications are most effective at reducing tissue temperature to optimal therapeutic levels. However, its efficacy in treating injured human subjects is not yet known. OBJECTIVE: To compare the efficacy of an intermittent cryotherapy treatment protocol with a standard cryotherapy treatment protocol in the management of acute ankle sprains. SUBJECTS: Sportsmen (n = 44) and members of the general public (n = 45) with mild/moderate acute ankle sprains. METHODS: Subjects were randomly allocated, under strictly controlled double blind conditions, to one of two treatment groups: standard ice application (n = 46) or intermittent ice application (n = 43). The mode of cryotherapy was standardised across groups and consisted of melting iced water (0 degrees C) in a standardised pack. Function, pain, and swelling were recorded at baseline and one, two, three, four, and six weeks after injury. RESULTS: Subjects treated with the intermittent protocol had significantly (p<0.05) less ankle pain on activity than those using a standard 20 minute protocol; however, one week after ankle injury, there were no significant differences between groups in terms of function, swelling, or pain at rest. CONCLUSION: Intermittent applications may enhance the therapeutic effect of ice in pain relief after acute soft tissue injury.