Jodie A. McClelland

Context : The purpose of this study was to describe young athletes’ trajectories of perceived quality of life (QOL) following anterior cruciate ligament injury and reconstruction, and to explore how athletes conceptualize QOL during recovery. Design : A mixed methods study integrating quantitative QOL trajectories with qualitative description of athletes’ individual experiences. Methods : Semistructured interviews were conducted with 13 Australian athletes (mean age: 21, 7 males and 6 females) 1-year after anterior cruciate ligament reconstruction. During interviews, participants rated their perceived QOL at 3 timepoints (preinjury, preoperative, and 1-y postoperative) using a visual analog scale (0–100). Participants were asked to discuss their injury, surgical, and recovery experiences, including perceptions and conceptualizations of QOL across time. Descriptive analyses were used to characterize QOL trajectories. Interview transcripts were coded and analyzed independently by 2 reviewers using inductive thematic analysis to identify themes related to the changes in QOL. Results : Athletes’ mean self-reported QOL exhibited a V -shaped trajectory: preinjury (80 [11]), preoperative (39 [22]), to 1-year postoperative (78 [12]). Qualitative analysis identified an overarching theme of sport injury–related growth, which provided insight into how athletes perceived and made sense of improvements in QOL. Sport injury–related growth was characterized by 4 distinct mechanisms: satisfaction with surgery (optimism regarding surgical outcomes), gratitude (identifying benefits of the injury experience), cognitive reframing (shifting focus to life domains unaffected by injury), and resilience (recognizing personal strength). Conclusion : Young athletes generally regained acceptable levels of perceived QOL at 1-year postoperative following anterior cruciate ligament reconstruction. The presence of sport injury–related growth mechanisms may help explain these favorable trajectories and should be considered when interpreting postoperative outcomes.

Collar height is a distinctive feature of court-sport footwear, yet its biomechanical effects remain underexplored. This study compared the effect of low-cut and high-cut footwear on lower-limb biomechanics during straight-line running and change-of-direction tasks in court-sport athletes (11 females, 11 males). During straight-line running, reduced ankle dorsiflexion (32-77% of gait cycle, mean difference [MD]: 2.6°) and toe-out angles (46-76%, MD: 2°), and increased knee abduction angles (14-20%, MD: 0.9°) were observed in high-cut footwear. During the change-of-direction task, reduced ankle dorsiflexion (28-64%, MD: 2.8°) and rearfoot inversion angles (72-87%, MD: 2.6°) were observed in high-cut footwear. Independent of collar height, female participants exhibited greater knee abduction angles during running (79-100%, MD: 5°), while they exhibited smaller knee flexion (38-49%, MD: 7.3°; and, 65-82%, MD: 9.6°), hip abduction angles (36-97%, MD: 8.6°), reduced knee extension moments (54-82%, MD: 0.8 Nm/kg), and greater hip abduction moments (33-40%, MD: 0.9 Nm/kg) during the change-of-direction task. Overall, our findings indicate that low-cut footwear allowed greater ankle mobility, while high-cut designs limited rearfoot inversion during lateral movements. Hip and knee biomechanics were similar across collar heights, but sex-based differences existed. Footwear collar selection should reflect common playing demands and individual biomechanics.

Current testing of small-arms weapons focuses on measuring accuracy in optimal, supported positions whereas using a more dynamic test may be more informative. Previous work has shown that accuracy, shot interval, and weapon stability degrades over prolonged shooting and only the latter two measures differ between weapon configurations. The aim of the current study was to evaluate muscle activity to understand if signs of fatigue could add information about the optimal ergonomic weapon. The 200 ms of electromyography from six upper limb muscles immediately before each of 60 shots for four weapon conditions were collected from 18 participants. Both frequency and amplitude showed signs of muscle fatigue over the 60 shots for most of the muscles, and amplitude was different in some muscles between conditions. This study shows that although participants can maintain accuracy with more difficult weapon configurations, this comes at the potential cost of muscle fatigue.

Ground reaction forces (GRFs) are known to be high during front foot contact of fast bowling deliveries in cricket. There is a lack of published data on the GRFs during follow through foot contacts. The aim of this study was to quantify and compare peak GRFs and impulse of the delivery stride and the follow through of fast bowling deliveries. Ten trained male fast bowlers (ball release speed mean ± SD; 32.6 ± 2.3 m/s) competing in the Men’s Victorian Premier League participated in the study. Peak GRF and impulse data were collected using in-ground force plates in a laboratory setting. Linear mixed modelling of GRFs and impulse showed a significant effect of foot strike (p < 0.001). Front foot contact had the greatest magnitude of peak vertical GRF (5.569 ± 0.334 BW) but was not significantly greater than back foot recontact (4.471 ± 0.285 BW) (p = 0.07). Front foot impact had the greatest vertical impulse (0.408 ± 0.018 BW·s) but was similar to back foot (0.377 ± 0.012 BW·s) and front foot (0.368 ± 0.006 BW·s) recontacts (p = 0.070 to 0.928). The high GRF and impulse during the follow through highlights the need for further kinetic and kinematic research on this phase of the fast bowling delivery.

The aim of this study was to determine whether there are differences in the accuracy and consistency of repeated lawn bowl deliveries between different bowling conditions and to describe the bias of bowls that missed the target (jack). Twenty-seven elite lawn bowl athletes were recruited to partake in the study. Participants delivered 16 bowls in four conditions: (i) forehand and (ii) backhand towards a target 23 metres away and (iii) forehand and (iv) backhand towards a target 27 metres away. The resting position of each bowl relative to the jack was described in terms of absolute displacement, width displacement and length displacement. For each participant and each condition, the average absolute displacement of deliveries was calculated as a measure of accuracy; the average width and length displacement was used to describe the bias of deliveries; and the bivariate variable error of absolute displacement was calculated as a measure of consistency. The forehand towards a target 23 metres away was significantly less accurate and consistent when compared with other conditions. There was a bias for greater width displacement of both forehand deliveries (p < 0.001). Analysing lawn bowls in this detail provides specific areas for coaching to improve lawn bowling performance.

Few studies have directly compared physical responses to relative loading strategies between men and women during overground walking. This study aimed to compare gait mechanics of men and women during overground load carriage. A total of 30 participants (15 male, 15 female) completed three 10-min walking trials while carrying external loads of 0%, 20% and 40% of body mass at a self-selected walking speed. Lower-body motion and ground reaction forces were collected using a three-dimensional motion capture system and force plates, respectively. Female participants walked with a higher cadence (p = 0.002) and spent less absolute time in stance (p = 0.010) but had similar self-selected walking speed (p = 0.750), which was likely due to the female participants being shorter than the male participants. Except for ankle plantarflexion moments, there were no sex differences in spatiotemporal, kinematic, or kinetic variables (p > 0.05). Increasing loads resulted in significantly lower self-selected walking speed, greater stance time, and changes in all joint kinematics and kinetics across the gait cycle (p < 0.05). In conclusion, there were few differences between sexes in walking mechanics during overground load carriage. The changes identified in this study may inform training programs to increase load carriage performance.

Background: Despite calf muscle strain injuries (CMSI) being problematic in many sports, there is a dearth of research to guide clinicians dealing with these injuries. The aim of this study was to evaluate the current practices and perspectives of a select group of international experts regarding the assessment, management and prevention of CMSI using in-depth semi-structured interviews. Results: Twenty expert clinicians working in elite sport and/or clinician-researchers specialising in the field completed interviews. A number of key points emerged from the interviews. Characteristics of CMSI were considered unique compared to other muscle strains. Rigor in the clinical approach clarifies the diagnosis, whereas ongoing monitoring of calf capacity and responses to loading exposure provides the most accurate estimate of prognosis. Athlete intrinsic characteristics, injury factors and sport demands shaped rehabilitation across six management phases, which were guided by key principles to optimise performance at return to play (RTP) while avoiding subsequent injury or recurrence. To prevent CMSI, periodic monitoring is common, but practices vary and data are collected to inform load-management and exercise selection rather than predict future CMSI. A universal injury prevention program for CMSI may not exist. Instead, individualised strategies should reflect athlete intrinsic characteristics and sport demands. Conclusions: Information provided by experts enabled a recommended approach to clinically evaluate CMSI to be outlined, highlighting the injury characteristics considered most important for diagnosis and prognosis. Principles for optimal management after CMSI were also identified, which involved a systematic approach to rehabilitation and the RTP decision. Although CMSI were reportedly difficult to prevent, on- and off-field strategies were implemented by experts to mitigate risk, particularly in susceptible athletes.

Defence acquisitions use accuracy measures as a discriminating factor in weapon purchases, but assessments are generally completed in static, supported postures at static targets with few differences being seen between configurations. The aim of this study was to investigate whether an assessment requiring repositioning between shots could reveal differences. Participants shot at a static target under four conditions: an unweighted rifle and the addition of a mass fixed at three different positions. Accuracy and timing as well as discomfort measures were captured and compared. Hit percentage, consistency and timing varied over time, and timing increased with the addition of mass in two out of the three conditions. There was an increase in discomfort with the addition of mass further from the participant. The results showed that relying on accuracy and consistency measures alone to make acquisition decisions could have the consequence of purchasing equipment not fit for the human. Practitioner Summary: This research shows that relying on accuracy and consistency measures alone to make weapon-system acquisition decisions could have the consequence of purchasing equipment not fit for the user. Further research should focus on 'upstream' issues such as muscle fatigue and aim point stability in order to better understand human-weapon-system interactions.