In clinic settings, factors such as time, cost, expertise, and technology feasibility limit the use of instrumented biomechanical analysis. Recent advances in commercial markerless motion capture systems can address patient ease-of-use factors, but are high cost and require specialised equipment, dedicated spaces, and technical expertise. As such, they present similar limitations to biomechanical analyses in clinic settings. Single-camera pose estimation techniques have generated cautious optimism for markerless gait analysis. However, parameters derived using low-cost and low-sample rate cameras commonly used in clinic settings are not yet accurate enough to detect change in complex movement systems. Video frame interpolation is a single-step process that artificially increases the sample rate of videos. This study applied video frame interpolation to videos of walking and demonstrates improved precision for step, stance, swing and double support times, as well as marginal improvements to the precision of ankle and knee joint angles, derived by single-camera pose estimation. Video frame interpolation potentially represents a delimiting factor for gait analysis in clinic settings, as limiting factors such as time, cost, technology feasibility and patient ease-of-use can be minimised.

Background Studded footwear can cause severe lacerations in rugby union; the prevalence of these injuries is currently unknown. Objective To summarise the skin and laceration injury prevalence in published epidemiological studies and to investigate any differences in skin injury risk between amateur and professional players. Design Systematic literature review and meta-analysis of epidemiological studies. Data sources PubMed, Web of Science, Scopus and Ovid. Eligibility criteria for selecting studies Prospective, epidemiological studies published in English after 1995, measuring a minimum of 400 match or 900 training exposure hours. Participants should be adult rugby union players (amateur or professional). The study should report a separate skin or laceration injury category and provide sufficient detail to calculate injury prevalence within this category. Results Twelve studies were included. Mean skin injury prevalence during matches was 2.4 injuries per 1000 exposure hours; during training sessions, the prevalence was 0.06 injuries per 1000 exposure hours. Skin injuries accounted for 5.3% of match injuries and 1.7% of training injuries. Skin injury risk was similar for amateur compared with professional players during matches (OR: 0.63, p=0.46.), but higher during training sessions (OR: 9.24, p=0.02). Conclusions The skin injury prevalence of 2.4 injuries per 1000 exposure hours is equivalent to one time-loss injury sustained during matches per team, per season. Amateur players are more likely to sustain skin injuries during training sessions than professional players. There is a need for more studies observing injuries among amateur players. Trial registration number PROSPERO CRD42015024027.

In competitive association football, wearing electronic performance and tracking system (EPTS) devices was approved in 2015. Safety concerns regarding their use have been raised; however, research and understanding is limited. Recently, FIFA has taken steps to assess possible injury mechanisms associated with wearing EPTS devices. This study identifies potential injury scenarios in football and associated impact energies. EPTS device use was first surveyed by questionnaire and semi-structured interviews. Unexpected, backward falls were highlighted as potential injury scenarios. An anthropomorphic test device (ATD), wearing a mock-EPTS device, was dropped onto 3G turf. Impact energy was 142.4 ± 42.1 and 5.8 ± 4.0 J whilst wearing and not wearing mock-EPTS devices respectively. Results indicate that wearing EPTS devices markedly increased impact energy experienced at the upper-back during falls. Further investigation into possible injury mechanisms (e.g., EPTS device shape and/or contact-area) of skin laceration and/or contusion risk, is warranted.

This study aimed to understand how tennis coaches perceive and approach the development of grip positions, a foundational skill in tennis. Professionally accredited coaches, classed as less (n = 140) or more (n = 86) experienced, participated in an online survey where they provided their perspectives on the importance of developing grip positions and their opinions on using physically constraining tools for coaching. Irrespective of coach experience level, the findings revealed that technique development and grip position training were ranked as the two most important components in foundational tennis skill development. The Semi-western grip for forehand (less: 68%; more: 65%), a combination of Continental and Eastern grips for double-handed backhand (less: 59%; more: 48.8%), and the Continental grip for serves (both: 94%) were identified as the most commonly taught positions for different shots. Perceived barriers to developing grip positions were out of habit (less: 62%; more: 56%), discomfort (less: 58%; more: 50%), and lack of confidence (less: 44%; more: 21%). Notably, 65% of coaches expressed an openness to incorporating physically constraining tools to enhance grip-specific skill development. Overall, this study serves as a foundational resource, guiding coaches in optimising their strategies for foundational tennis development, prompting further research in this area.

Professional rugby union players experience an injury once every 10 matches, and up to 23% of these injuries are skin lacerations. Current regulations to assess laceration injury risk of cleated footwear involve two optional mechanical tests for manufacturers: a drop test and a pendulum test. However, there is limited rationale for these tests and associated impact parameters. A questionnaire among 191 rugby players showed that the ruck is the most prevalent game scenario in which skin laceration injuries occur. During the ruck, laceration injuries result from stamping movements by players wearing cleated footwear. A biomechanical study was conducted to obtain game-relevant impact parameters of stamping in the ruck. Eight participants were asked to perform 10 stamps on an anthropomorphic test device. Kinetic and kinematic data were clustered – identifying two distinct phases of the stamp motion – providing test parameters for mechanical assessment of skin laceration risk. A two-phase mechanical test was designed to quantify laceration injury risk of individual cleats. Phase one represents initial impact and phase two represents the subsequent raking motion as observed in the biomechanical study. Each phase is based on the impact parameters of observed stamping impacts. The developed test method has the potential to be adapted as an international standard for assessing laceration injury risk of cleated footwear. Future research is required to assess the repeatability of this method and its sensitivity to laceration injury.