Dr Suzi Edwards

The tackle is the in-game activity with the greatest risk for injury in collision sports. Qualitative match analysis has associated injury risk with tackle technique (e.g. tackle height, head position before contact). This exploratory study used gold-standard three-dimensional (3D) motion capture to investigate whether prior instructions to a tackler to execute different torso tackle types altered their tackle technique. Fifteen amateur-level rugby code players performed four sets of 10 tackle trials after instructions from an expert coach: two Australian National Rugby League (NRL) coaching manual instructions on upper and lower torso tackle height (UpperNRL, LowerNRL); and two novel variants that altered the tackler¿s contact with the ball carrier¿s upper torso (UpperPop) via a vertical ¿pop action¿, or mid-torso (MidTorso) via increasing the contact height to the mid-torso. 3 D motion capture confirmed a favourable ¿head up and forward¿ gaze focus on ball carrier before contact and a ¿straight back¿ posture was more evident in UpperPop instruction than other instructions, with the least flexion for the head, trunk, trunk-pelvis, thoracolumbar and lumbopelvic (p < 0.01). MidTorso also attained a more optimal ¿head up and forward¿ and a ¿straight back¿ posture than a LowerNRL (p < 0.001). ¿Leg drive on contact¿ revealed ankle, hip (p < 0.01) and thigh angles (p < 0.05) differences, likely to reflect the UpperPop ¿pop action¿ instruction than other instructions. For coaches, this study demonstrated that amateur-level rugby-code players could follow instruction from an expert coach to execute tackling techniques within a session. Inclusion of tackle specific coaching instruction training program may be a viable injury reduction strategy.

Background: Wearable inertial sensor technology (WIST) systems provide feedback, aim-ing to modify aberrant postures and movements. The literature on the effects of feedback from WIST during work or work-related activities has not been previously summarised. This review examines the effectiveness of feedback on upper body kinematics during work or work-related activities, along with the wearability and a quantification of the kinematics of the related device. Methods: The Cinahl, Cochrane, Embase, Medline, Scopus, Sportdiscus and Google Scholar databases were searched, including reportsfrom January 2005 to July 2021. The included studies were summarised descriptively and the evidence was assessed. Results: Fourteen included studies demonstrated a ¿limited¿ level of evidence supporting posture and/or movement behaviour improvements using WIST feedback, with no improvements in pain. One study assessed wearability and another two investigated comfort. Studies used tri-axial accelerometers or IMU integration (n = 5 studies). Visual and/or vibrotactile feedback was mostly used. Most studies had a risk of bias, lacked detail for methodological reproducibility and displayed inconsistent reporting of sensor technology, with validation provided only in one study. Thus, we have proposed a minimum ¿Technology and Design Checklist¿ for reporting. Conclusions: Our findings suggest that WIST may improve posture, though not pain; however, the quality of the studies limits the strength of this conclusion. Weara-bility evaluations are needed for the translation of WIST outcomes. Minimum reporting standards for WIST should be followed to ensure methodological reproducibility. Précis: This review summa-rises studies reporting on feedback from wearable inertial sensor technology (WIST) devices that aim to improve posture and/or movement behaviour during workplace-related tasks. The included studies lacked methodological reproducibility; therefore, a ¿Technology and Design Checklist¿ was proposed. A ¿limited¿ level of evidence supported changes in posture/movement behaviour using WIST, with no improvements in pain, though the study quality limits the strength of these findings.

Background: Exposure to thousands of head and body impacts during a career in contact and collision sports may contribute to current or later life issues related to brain health. Wearable technology enables the measurement of impact exposure. The validation of impact detection is required for accurate exposure monitoring. In this study, we present a method of automatic identification (classification) of head and body impacts using an instrumented mouthguard, video-verified impacts, and machine-learning algorithms. Methods: Time series data were collected via the Nexus A9 mouthguard from 60 elite level men (mean age = 26.33; SD = 3.79) and four women (mean age = 25.50; SD = 5.91) from the Australian Rules Football players from eight clubs, participating in 119 games during the 2020 season. Ground truth data labeling on the captures used in this machine learning study was performed through the analysis of game footage by two expert video reviewers using SportCode and Catapult Vision. The visual labeling process occurred independently of the mouthguard time series data. True positive captures (captures where the reviewer directly observed contact between the mouthguard wearer and another player, the ball, or the ground) were defined as hits. Spectral and convolutional kernel based features were extracted from time series data. Performances of untuned classification algorithms from scikit-learn in addition to XGBoost were assessed to select the best performing baseline method for tuning. Results: Based on performance, XGBoost was selected as the classifier algorithm for tuning. A total of 13,712 video verified captures were collected and used to train and validate the classifier. True positive detection ranged from 94.67% in the Test set to 100% in the hold out set. True negatives ranged from 95.65 to 96.83% in the test and rest sets, respectively. Discussion and conclusion: This study suggests the potential for high performing impact classification models to be used for Australian Rules Football and highlights the importance of frequencies <150 Hz for the identification of these impacts.

Objective: The purpose of this study was to determine if there is a relationship between pain and movement kinematics during functional tasks, evaluated over time, in individuals with chronic idiopathic neck pain. Methods: Ten participants with chronic idiopathic neck pain performed 2 functional tasks (overhead reach to the right and putting on a seatbelt) while evaluated using 8 Oqus 300+ cameras. Kinematic variables included joint angles and range of motion (ROM) (°), head segment relative to neck segment (head-neck [HN]); and head/neck segment relative to upper thoracic segment (head/neck-trunk), velocity (m/s), and time (% of movement phase). Pain was quantified using a 100-mm visual analog scale. Linear mixed effects regression models were used to analyze associations between pain and kinematic variables adjusting for treatment group. Results: For overhead reach, higher pain was associated with less HN peak rotation at baseline (ß = ¿0.33; 95% CI -0.52 to ¿0.14, P = .003) and less HN total rotation ROM at 6 months (ß = ¿0.19; 95% CI ¿0.38 to ¿0.003, P = .048). For the seatbelt task, higher pain was associated with less HN peak rotation (ß = ¿0.52; 95% CI -0.74 to ¿0.30 to ¿0.74, P < .001) and less HN total rotation ROM at baseline (ß = ¿0.32; 95% CI ¿0.53 to ¿0.10, P = .006). No other movement variables demonstrated meaningful relationships with pain for the reach or seatbelt tasks. Conclusion: Higher pain is associated with less HN peak and total rotation during functional reaching tasks requiring head rotation. Recognizing altered functional kinematics in individuals with chronic neck pain may assist patient management.

PURPOSE: Patellar tendon abnormality (PTA) on diagnostic imaging is part of the diagnostic criteria for patellar tendinopathy. PTA and altered landing strategies are primary risk factors that increase the likelihood of asymptomatic athletes developing patellar tendinopathy. Therefore, the aim of this study was to examine the risk factors that are predictors of the presence and severity of a PTA in junior pre-elite athletes. METHODS: Ten junior pre-elite male basketball athletes with a PTA were matched with 10 athletes with normal patellar tendons. Participants had patellar tendon morphology, Victorian Institute of Sport Assessment (VISA) score, body composition, lower limb flexibility, and maximum vertical jump height measured before performing five successful stop-jump tasks. During each stop-jump task, both two-dimensional and three-dimensional kinematics and ground reaction forces were recorded. Multiple regression analyses were used to identify factors for estimating PTA presence and severity, and discriminate analysis was used to classify PTA presence. RESULTS: Sixty-eight percent of variance for presence of a PTA was accounted for by hip joint range of motion (ROM) and knee joint angle at initial foot-ground contact (IC) during stop-jump task and quadriceps flexibility, whereas hip joint ROM during stop-jump task and VISA score accounted for 62% of variance for PTA severity. Prediction of the presence of a PTA was achieved with 95% accuracy and 95% cross-validation. CONCLUSIONS: An easily implemented, reliable, and valid movement screening tool composed of three criteria enables coaches and/or clinicians to predict the presence and severity of a PTA in asymptomatic athletes. This enables identification of asymptomatic athletes at higher risk of developing patellar tendinopathy, which allows the development of effective preventative measures to aid in the reduction of patellar tendinopathy injury prevalence. Copyright © 2013 by the American College of Sports Medicine.

Purpose: Risk factors associated with a clinical presentation of patellar tendinopathy are patellar tendon ultrasonographic abnormality (PTA) and excessive loading. It remains unknown whether characteristics of an athlete's landing technique contribute to this excessive patellar tendon loading. This study investigated whether asymptomatic athletes with and without PTA had different landing strategies and hypothesized that asymptomatic athletes with a PTA would create higher patellar tendon loading and a different lower-limb landing strategy compared with athletes with normal patellar tendons. Methods: Seven athletes with no previous history or clinical signs of patellar tendon injury with a PTA were matched to athletes with normal patellar tendons (controls). Participants performed five successful trials of a stop-jump task, which involved a simultaneous two-foot horizontal and then vertical landing. During each trial, the participants' ground reaction forces and lower-limb electromyographic data were recorded, the three-dimensional kinematics measured, and the peak patellar tendon force calculated by dividing the net knee joint moment by the patellar tendon moment arm. Results: Significant between-group differences in landing technique were mostly observed during the horizontal landing phase. Participants with a PTA created similar patellar tendon loading to the controls, but with altered sequencing, by landing with significantly greater knee flexion and extending their hips while the controls flexed their hips as they landed, reflecting a different muscle recruitment order compared with the PTA group. Conclusions: The crucial part in the development of PTA and, in turn, patellar tendinopathy may not be the magnitude of the patellar tendon load but rather the loading patterns. This research provides clinicians with important landing assessment criteria against which to identify athletes at risk of developing patellar tendinopathy. Copyright © 2010 by the American College of Sports Medicine.

This study aimed to determine whether the landing phase of a drop landing (DL) differed with respect to a complete jumping and landing task, a spike jump (SJ), and whether fatigue altered the landing of these movements. Fourteen male volleyball players performed five DL and SJ in a counterbalanced order under two experimental conditions: non-fatigued and fatigued. Fatigue, induced by repetitive jumping sets, was confirmed by decrements in vertical jump height >25% and increased blood lactate >6 mmol/L. Each landing task was characterized by the resultant ground reaction forces (GRF), sagittal plane kinematics and muscle recruitment patterns of six lower extremity muscles. Two-way repeated analysis of variance results indicated a main effect of movement on many of the GRF, kinematic and electromyographic variables characterizing landing, indicating that the two tasks required substantially different lower limb biomechanics during landing. Although fatigue did not alter the GRF in either task, there were significant movement × fatigue condition interactions. The significant between-task differences in the biomechanical variables characterizing landing and the differential effects of fatigue on each landing task, question the validity of using a DL as an experimental task to investigate lower limb landing mechanics of whole jumping and landing movements. © 2009 John Wiley & Sons A/S.