Author contributorship: Carel T. Viljoen -Conception and design of the study, literature search, review of literature for final inclusion of relevant studies, data extraction, level of evidence rating of included studies, quality assessment of included studies, data interpretation, manuscript write-up, manuscript editing Dina C. Janse van Rensburg -Conception and design of the study, review of literature for final inclusion of relevant studies, data extraction, manuscript editing Evert Verhagen -Conception and design of the study, review of literature for final inclusion of relevant studies, data extraction, manuscript editing Willem van Mechelen -Manuscript editing Rita Tomas -Data extraction, manuscript editing Marlene Schoeman -Data extraction, manuscript editing, level of evidence rating of included studies Susan Scheepers -Literature search, manuscript editing Elzette Korkie -Quality assessment of included studies, manuscript editing Data sharing statement: No additional data are available Funding: None Conflict of interests:The authors declare that there are no conflict of interests.

Background: We aimed to determine if a shock absorbing pylon (SAP) influenced the ground reaction force characteristics and the shock absorbing mechanisms compared to a rigid pylon (Rigid) during the loading phase in running. Objectives: To determine if the SAP influences the mechanisms of loading compared to the Rigid condition. Study Design: A convenience sample of transtibial amputees participated in a laboratory-based study. The prosthetic set-up was randomly altered fd\sdsd. Methods: Five recreationally active male transtibial amputees age: 18-50 years; mean mass: 86.7 ± 17.5 kg; height: 1.77 ± 0.07 m) volunteered from a population-based sample. They completed a within-participant-designed study assessing a SAP and a Rigid condition during running. Kinematic and kinetic data were collected during two sessions following a one-week customization period. Results: Loading rate, peak vertical and horizontal ground reaction forces and the time to each measure along with knee and hip angular displacement, absorbing powers and work done between the SAP and Rigid conditions were not systematically affected by the prosthetic condition. Conclusions: The effect of the SAP was minimal and inconsistent in the loading phase, with only some amputees presenting higher and others with lower values for the tested variables. Clinical relevanceThe inclusion of a prosthetic shock absorber in the form of a SAP did not systematically alter the kinetic characteristics or shock absorbing mechanisms of the residual joints. It appears that the prescription of a SAP is not justified for these recreationally active amputees.

Background: The South African Rugby Union’s BokSmart programme currently educates coaches and referees on concussion. Rugby players are often more familiar with their teammates than the coach or referee. Therefore they are well-positioned to play a pivotal role in rugby safety if they have adequate knowledge to identify subtle signs and abnormal behaviour displayed by a concussed teammate. However, no programme focuses on concussion education among South African rugby players and there is a dearth of literature on concussion education programmes among rugby players which could lead to safer return to play (RTP) habits.Objectives: To evaluate South African rugby players’ concussion knowledge and attitudes/behaviours regarding RTP following a concussion.Methods: A descriptive, cross-sectional study was used. Participants (n=294) were divided into junior amateur high school (JAHS) (n=216) and senior amateur club (SAC) (n=78) players. The modified RoCKAS-ST questionnaire was used to evaluate their concussion knowledge index (CKI) and concussion attitudes/behaviours index (CAI) regarding RTP.Results: On average, 62% (JAHS) and 60% (SAC) of the CKI questions were answered correctly. JAHS participants correctly identified 66% of concussion symptoms, similarly to the SAC participants (63%), rendering similar (p=0.37) overall CKI scores when comparing the two groups. The CAI questions yielded similar (p=0.98) results between the groups, reporting safe responses in 66% (JAHS) and 67% (SAC) of the items.Discussion and conclusion: Junior and senior South African amateur rugby players lacked approximately one-third of essential concussion knowledge, which may lead to a display of unsafe attitudes/behaviours to concussion and RTP. Further research is warranted to inform educational programmes on concussion among rugby players.

ObjectiveTo review and frequently update the available evidence on injury risk factors and epidemiology of injury in trail running.DesignLiving systematic review. Updated searches will be done every 6 months for a minimum period of 5 years.Data sourcesEight electronic databases were searched from inception to 18 March 2021.Eligibility criteriaStudies that investigated injury risk factors and/or reported the epidemiology of injury in trail running.ResultsNineteen eligible studies were included, of which 10 studies investigated injury risk factors among 2 785 participants. Significant intrinsic factors associated with injury are: more running experience, level A runner and higher total propensity to sports accident questionnaire (PAD-22) score. Previous history of cramping and postrace biomarkers of muscle damage is associated with cramping. Younger age and low skin phototypes are associated with sunburn. Significant extrinsic factors associated with injury are neglecting warm-up, no specialised running plan, training on asphalt, double training sessions per day and physical labour occupations. A slower race finishing time is associated with cramping, while more than 3 hours of training per day, shade as the primary mode of sun protection and being single are associated with sunburn. An injury incidence range 0.7–61.2 injuries/1000 hours of running and prevalence range 1.3% to 90% were reported. The lower limb was the most reported region of injury, specifically involving blisters of the foot/toe.ConclusionLimited studies investigated injury risk factors in trail running. Our review found eight intrinsic and nine extrinsic injury risk factors. This review highlighted areas for future research that may aid in designing injury risk management strategies for safer trail running participation.PROSPERO registration numberCRD42021240832.

A unilateral transtibial amputation causes a disruption to the musculoskeletal system, which results in asymmetrical biomechanics. The current study aimed to assess the movement asymmetry and compensations that occur as a consequence of an amputation when performing a countermovement vertical jump. Six unilateral transtibial amputees and 10 able-bodied (AB) participants completed 10 maximal vertical jumps, and the highest jump was analyzed further. Three-dimensional lower limb kinematics and normalized (body mass) kinetic variables were quantified for the intact and prosthetic sides. Symmetry was assessed through the symmetry index (SI) for each individual and statistically using the Mann-WhitneyUtest between the intact and prosthetic sides for the amputee group. A descriptive analysis between the amputee and AB participants was conducted to explore the mechanisms of amputee jumping. The amputee jump height ranged from 0.09 to 0.24 m. In the countermovement, all ankle variables were asymmetrical (SI > 10%) and statistically different (p< .05) for the amputees. At the knee and hip, there was no statistical difference between the intact and prosthetic sides range of motion, although there was evidence of individual asymmetry. The knees remained more extended compared with the AB participants to prevent collapse. In propulsion, the prosthesis did not contribute to the work done and the ankle variables were asymmetrical (p< .05). The knee and hip variables were not statistically different between the intact and prosthetic sides, although there was evidence of functional asymmetry and the contribution tended to be greater on the intact compared with the prosthetic side. The lack of kinetic involvement of the prosthetic ankle and both knees due to the limitation of the prosthesis and the altered musculoskeletal mechanics of the joints were the reason for the reduced height jumped.