Risk Of Back Injury Research Articles

Technical pace bowling coaching of adolescent cricketers: A survey on practices and barriers

In cricket pace bowling, research has determined kinematic correlates to ball release speed and lumbar bone stress injury. Coaches have an important role in guiding the development of the bowling action of adolescent pace bowlers; however, it is not clear whether their knowledge and practices align with improving ball release speed and reducing lower back injury risk. This study had three aims: 1) to describe the technical coaching practices of adolescent pace bowlers, 2) to identify the barriers that coaches face in the implementation of such practices, and 3) to determine the relationship between coaches’ demographic characteristics and the frequency of technical coaching. This study used a cross-sectional survey study design combined with a purposive sampling approach. Participants were cricket coaches (n = 130) in Australia aged over 18 years, who coached adolescent cricket teams (10–19 years old). Only 11.3% of coaches “occasionally” engaged in technical bowling coaching in the off-season, which increased to 37.1% during the in-season. When technical bowling coaching was undertaken, it was most common for it to last “15–30 min/session” (34.5% of coaches in the off-season and 38.2% in the in-season). The most common barrier to technical bowling coaching during the off-season was limited access to players, while barriers during the in-season were minimal and varied. Younger coaches and older players were associated with more frequent technical coaching in the off-season. Future coaching educational programmes could help coaches to work around the player-access barrier by encouraging them to prescribe training drills in the off-season.

Characterizing the Compressive Force at L5/S1 During Patient Transfer From Bed to Wheelchair.

The peak compressive forces at L5/S1 during patient transfers have been estimated. However, no study has considered the actual patient body weight that caregivers had to handle during transfers. We developed a simple kinematic model of lifting to address this limitation. Fifteen prospective health care providers transferred a 70-kg individual who mimicked a patient ("patient") from bed to wheelchair. Trials were acquired with the patient donning (weighted) and doffing (unweighted) a 5-kg weight belt. Trials were also acquired with and without knee assistance and a mechanical lift. During trials, kinematics and kinetics of transfers were recorded to estimate the peak compressive force at L5/S1 using static equilibrium equations. The peak compressive force was associated with the transfer method (P < .0005), and the compressive force was 68% lower in lift-assisted than manual transfer (2230 [SD = 433]N vs 6875 [SD = 2307]N). However, the peak compressive force was not associated with knee assistance, nor with a change in the patient body weight. Our results inform that mechanical loading exceeding the National Institute for Occupational Safety and Health safety criterion occurs during patient transfers, confirming a high risk of lower back injuries in caregivers. However, the risk can be mitigated with the use of a mechanical lift.

Simulation analysis of low back forces in Snatch and Clean & Jerk movements via digital human modelling.

Weightlifting is an Olympic sport for dynamic strength and power, and requires the execution of different lifting techniques It is important to analyze the forces subjected to the lower back during weightlifting movements to prevent injuries. Digital Human Modeling (DHM) is a powerful tool that can be used to analyze and optimize the performance of humans while doing their work or activities. The purpose of this study is to present a simulation analysis of the lower back forces during the execution of two weightlifting techniques: Snatch (SN) and Clean & Jerk (CJ), with different loads and for both genders. Digital Human modelling through JACK simulation package was used analyze the forces exerted on the lumbosacral area (L5-S1) of the lower back in order to determine the risk for low back injuries. The level of compression and shear forces recommended by the literature have been set as thresholds. The simulaitons were performed in male and female models, with loads from 20-100kg. The results show that any weight higher than 60 kg in both movements poses risk for the weightlifters in terms of compression and shear forces. It has been observed that weightlifters can lift greater loads in the CJ technique compared to the SN technique. Furthermore, females are able to lift higher loads with lower risk of injuries. Weightlifting is a high-risk activity due to the high levels of shear and compression forces that the body is exposed to during the lifting techniques. Digital Human Modeling holds significant value due to their ability to facilitate the exploration of diverse conditions within a safe environment, devoid of any potential harm to human subjects.

Implementing an accelerometer-based pelvis segment for low back kinetic analyses during dynamic movement tasks

An accelerometer-based pelvis has been employed to study segment and joint kinematics during scenarios involving close human-object interface and/or line-of-sight obstructions. However, its accuracy for examining low back kinetic outcomes is unknown. This study compared reaction moments and contact forces of the L5S1 joint calculated with an accelerometer-based and optically tracked pelvis segment. An approach to correct the global pelvis position as a function of thigh angle was developed. One participant performed four dynamic tasks: forward bend, squat, sit-to-stand-to-sit, and forward lunge. A standard bottom-up inverse dynamics approach was used and the root mean square error (RMSE) and coefficient of determination (R2) were calculated to examine kinetic differences between the optical and accelerometer approaches. The RMSE observed for L5S1 reaction flexion-extension moments ranged from 1.32 Nm to 2.20 Nm (R2 ≥ 0.98). The RMSE for net shear and compression reaction forces ranged from 2.13 to 10.45 N and 0.63 – 4.96 N, respectively. Similarly, the RMSE for L5S1 joint contact shear and compression ranged from 13.45 N to 19.51 N (R2 ≥ 0.85) and 31.18 N – 55.97 N (R2 ≥ 0.97), respectively. In conclusion, the accelerometer-based pelvis together with the approach to correct the global pelvis position is a feasible approach for computing low back kinetics with a single equivalent muscle model. The observed error in joint contact forces represents less than 5 % of the NIOSH recommended action limits and is unlikely to alter the interpretation of low back injury risk.

Does Overhead Squat Performance Affect the Swing Kinematics and Lumbar Spine Loads during the Golf Downswing?

The performance of the overhead squat may affect the golf swing mechanics associated with golf-related low back pain. This study investigates the difference in lumbar kinematics and joint loads during the golf downswing between golfers with different overhead squat abilities. Based on the performance of the overhead squat test, 21 golfers aged 18 to 30 years were divided into the highest-scoring group (HS, N = 10, 1.61 ± 0.05 cm, and 68.06 ± 13.67 kg) and lowest-scoring group (LS, N = 11, 1.68 ± 0.10 cm, and 75.00 ± 14.37 kg). For data collection, a motion analysis system, two force plates, and TrackMan were used. OpenSim 4.3 software was used to simulate the joint loads for each lumbar joint. An independent t-test was used for statistical analysis. Compared to golfers demonstrating limitations in the overhead squat test, golfers with better performance in the overhead squat test demonstrated significantly greater angular extension displacement on the sagittal plane, smaller lumbar extension angular velocity, and smaller L4-S1 joint shear force. Consequently, the overhead squat test is a useful index to reflect lumbar kinematics and joint loading patterns during the downswing and provides a good training guide reference for reducing the risk of a golf-related lower back injury.

Core stability exercise for the impact of weightlifting and deadlifting on herniated nucleus pulposus (HNP): a systematic review

Background: Herniated nucleus pulposus or disc herniation is a serious medical condition, the common cause of sciatic pain, and the most common indication for spine surgery. People doing athletic sports, especially weightlifting and deadlifting, may face significant acute and overuse spinal injuries that can cause HNP. Core stability exercise (CSE) improves athletes' sports performance and can prevent injury. This systematic review aims to determine the impact of core stability exercises on weightlifting and deadlifting on herniated nucleus pulposus. Method: According to PRISMA recommendations, a systematic review using an online database was carried out. The inclusion criteria set includes studies regarding the impact of core stability exercise on deadlifting and weightlifting to prevent HNP, using adult samples&gt;18 years old and providing the type of CSE exercise. In contrast, the exclusion criteria were studied not available in full text and not available in Bahasa or English. Study quality assessments were done using a checklist for the Joanna Briggs Institute. Result: Ten studies are included in this systematic review, consisting of six randomized controlled trials, two review articles, one case-control study, and one prospective cohort study. The CSE effectively improves the endurance, strength, mobility, and dynamic balance of core muscles, especially spinal muscles, which can prevent back injury, especially for weightlifters and dead lifters. Core stability exercises should be incorporated into athletes' training programs to improve sports performance and reduce the risk of back injury, especially HNP. Conclusion: The CSE effectively improves the endurance, strength, mobility, and dynamic balance of core muscle, especially spinal muscle, which can prevent back injury in athletes, especially weightlifters and dead lifters.

Development of a Restraint System for Rear-Facing Car Seats

In self-driving vehicles, passengers can set their seats in an unconventional seating position, such as rear-facing. Sitting in such an orientation can increase the risk of whiplash in the head-and-neck system in a frontal impact, as frontal crashes usually have higher severities compared with rear-end crashes. This paper shows that a forward-facing front seat optimised for rear-impact protection needs to be redesigned to be used as a rear-facing seat. In the second and main part of this paper, a restraint system for rear-facing car seats is developed, and frontal impact simulations with 64 km/h of delta-V are used to evaluate its performance. The designed seating system comprises two rigid torso plates, a fixed recliner and an energy absorber under the seat pan. Without using the developed restraint system, the 50th percentile male human model is exposed to neck shear forces exceeding 600 N. With the developed restraint system, neck shear forces are less than 350 N in frontal impacts with 64 km/h of delta-V. Apart from whiplash, the risk of head, chest, lower extremity and lower back injuries are also evaluated. The results confirm that the developed restraint system successfully protects the occupant since all assessment criteria values are lower than the injury assessment reference values.

Evaluating adaptiveness of an active back exosuit for dynamic lifting and maximum range of motion

Back exosuits deliver mechanical assistance to reduce the risk of back injury, however, minimising restriction is critical for adoption. We developed the adaptive impedance controller to minimise restriction while maintaining assistance by modulating impedance based on the user’s movement direction and nonlinear sine curves. The objective of this study was to compare active assistance, delivered by a back exosuit via our adaptive impedance controller, to three levels of assistance from passive elastics. Fifteen participants completed five experimental blocks (4 exosuits and 1 no-suit) consisting of a maximum flexion and a constrained lifting task. While a higher stiffness elastic reduced back extensor muscle activity by 13%, it restricted maximum range of motion (RoM) by 13°. The adaptive impedance approach did not restrict RoM while reducing back extensor muscle activity by 15%, when lifting. This study highlights an adaptive impedance approach might improve usability by circumventing the assistance-restriction trade-off inherent to passive approaches. Practitioner summary: This study demonstrates a soft active exosuit that delivers assistance with an adaptive impedance approach can provide reductions in overall back muscle activity without the impacts of restricted range of motion or perception of restriction and discomfort.

The Kinematics of Fixed-Seat Rowing: A Structured Synthesis.

Olympic-style sliding-seat rowing is a sport that has been extensively researched, with studies investigating aspects related to the physiology, biomechanics, kinematics, and the performance of rowers. In contrast, studies on the more classic form of fixed-seat rowing are sparse. The aim of this study is to address this lacuna by analysing for the first time the specific kinematics of fixed-seat rowing as practised by able-bodied athletes, thus (i) documenting how this technique is performed in a manner that is replicable by others and (ii) showing how this technique compares and contrasts with the more standard sliding-seat technique. Fixed-seat rowing was replicated in a biomechanics laboratory where experienced fixed-seat rowers, marked with reflective markers following the modified Helen-Hayes model, were asked to row in a manner that mimics rowing on a fixed-seat boat. The findings from this study, complimented with data gathered through the observation of athletes rowing on water, were compared to sliding-seat ergometer rowing and other control experiments. The results show that, in fixed-seat rowing, there is more forward and backward thoracic movement than in sliding-seat rowing (75-77° vs. 44-52°, p < 0.0005). Tilting of the upper body stems was noted to result from rotations around the pelvis, as in sliding-seat rowing, rather than from spinal movements. The results also confirmed knee flexion in fixed-seat rowing with a range of motion of 30-35°. This is less pronounced than in standard-seat rowing, but not insignificant. These findings provide a biomechanical explanation as to why fixed-seat rowers do not have an increased risk of back injuries when compared with their sliding-seat counterparts. They also provide athletes, coaches, and related personnel with precise and detailed information of how fixed-seat rowing is performed so that they may formulate better and more specific evidence-based training programs to meliorate technique and performance.

Feature Identification Framework for Back Injury Risk in Repetitive Work With Application in Sheep Shearing.

Lower back injuries are a serious global problem. Most of these injuries occur over time with repeated sub-acute stresses. Neuromuscular control dysfunction could predict injury, however injuries are almost never observed alongside this data. No labels are available to identify important features that may be predictive of injury. While there are many individual differences in injury development, the population trend is that each individual's injury tolerance decreases over time with exposure, indicating a monotonic process. This paper proposes a framework for identifying key features of injury using an unsupervised technique that exploits knowledge of injury aetiology by analysing which features contribute to the popular trend using weak monotonicity from data segmented by task repetitions. The feature selection also evaluates feature redundancy. The efficacy of the framework is demonstrated through data from on-site sheep shearers over one day using 17 wearable inertial measurement units and 16 surface electromyography (sEMG) sensors. Consistent with literature, the results demonstrate sEMG features derived from the erector spinae and multifidus muscles are the most important indicators for lower back injury. To evaluate the performance of the proposed population-trend based unsupervised feature selection technique, the self-reported fatigue information is treated as some 'ground truth' information so that this proposed technique can compare with 5 existing unsupervised feature selection techniques. The proposed technique is shown to be the most consistent with the self-reported fatigue information, demonstrating the effectiveness of the proposed method.

Staff Low Back Injury Risk During Assisted Falls Virtual Reality Simulations.

Assisted falls occur when staff try to minimize the impact of falls by slowing a patient's descent. Assisting a patient fall may decrease patient injury risk, but biomechanical risk of injury to staff has not been evaluated. Assisted falls virtual reality (VR) simulations were conducted to examine staff low back injury risk during common assisted falls scenarios. VR simulations of a toilet to wheelchair transfer were developed with a male patient avatar for three assisted falls scenarios: standing up from toilet, sitting down on wheelchair, and ambulation. Patient avatar weight was modified to reflect normal, underweight, and overweight adult patients. The average spinal compression force at L5/S1 was calculated for each participant with five trials per three scenarios while utilizing physical ergonomic techniques and compared to the safe spinal compression limit of 3,400 Newtons (N). Six staff participants completed 90 VR simulations in total. The average calculated spinal compression force ranged from 7,132 N to 27,901 N. All participant trials exceeded the safe spinal compression limit of 3,400 N for every assisted falls scenario and avatar weight despite application of ergonomic techniques including wide stance, knees bent, and backs straight. Staff are at risk for low back injury if they assist falls regardless of the adult patient weight and application of ergonomic techniques. Safer alternatives like the implementation of mobility screening tools and safe patient handling and mobility technology are needed to help prevent assisted falls to decrease injury risk to both patients and staff.

Effects of Ground Slopes on Erector Spinae Muscle Activities and Characteristics of Golf Swing.

(1) Background: 'Slope' refers to the position faced by golfers on the course. Research on the recruitment strategies of thoracolumbar erector spinae during golf swings on different slopes may help us to understand some underlying mechanisms of lower back pain. (2) Purpose: The purpose of the present study is to assess electromyography (EMG) patterns of the erector spinae muscles (ES) and the kinematics of the trunk and swing parameters while performing golf swings on three different ground slopes: (1) no slope where the ball is level with the feet (BLF), (2) a slope where the ball is above the feet (BAF), and (3) a slope where the ball is below the feet (BBF). Furthermore, the present study evaluates the effect of slope on the kinematics of the trunk, the X-factor angle, and the hitting parameters. (3) Methods: Eight right-handed recreational male golfers completed five swings using a seven-iron for each ground slope. Surface electromyograms from the left and right sides of the ES thoracolumbar region (T8 and L3 on the spinous process side) were evaluated. Each golf swing was divided into five phases. Kinematics of the shoulder, trunk, and spine were evaluated, and the ball speed, swing speed, carry, smash factor, launch angle, and apex were measured using Caddie SC300. (3) Results: The muscle activity of the BAF and BBF slopes was significantly lower than that of the BLF slope during the early follow-through phase of the thoracic ES on the lead side (i.e., left side) and during the acceleration and early follow-through phases of the lumbar ES on the lead side. The lead and trail side (i.e., right side) lumbar ES were more active during acceleration than the thoracic ES. Additionally, the trends of the lead and trail sides of the thoracolumbar regions on the three slopes were found to be the same across the five phases. Trunk angle and X-factor angles had no significant differences in address, top of backswing, or ball impact. The maximum separation angles of the X-factor appeared in the early phase of the downswing for all the three slopes. Regarding smash factor and launch angle, there were no significant differences between the three slopes. The ball speed, swing speed, carry, and apex were higher on BLF than on BAF and BBF slopes. (4) Conclusion: The findings suggest that amateur golfers face different slopes with altered muscle recruitment strategies. Specifically, during the acceleration phase of the golf swing, the BAF and the BBF slopes, compared with the BLF slope, significantly underactivated the lead side thoracolumbar erector spinae muscles, thereby increasing the risk of back injury. Changes in muscle activity during critical periods may affect neuromuscular deficits in high-handicap players and may have implications for the understanding and development of golf-related lower back pain. In addition, the X-factor angle was not affected by the slope, however, it can be found that the hitting parameters on the BLF slope are more dominant than on the other slopes.

A Novel Passive Back-support Exoskeleton with a Spring-cable-differential for Lifting Assistance.

Lower back injuries are the most common work-related musculoskeletal disorders. As a wearable device, a back-support exoskeleton (BSE) can reduce the risk of lower back injuries and passive BSEs can achieve a low device weight. However, with current passive BSEs, there is a problem that the user must push against the device when lifting the leg to walk, which is perceived as particularly uncomfortable due to the resistance. To solve this problem, we propose a novel passive BSE that can automatically distinguish between lifting and walking. A unique spring-cable-differential acts as a torque generator to drive both hip joints, providing adequate assistive torque during lifting and low resistance during walking. The optimization of parameters can accommodate the asymmetry of human gait. In addition, the assistive torque on both sides of the user is always the same to ensure the balance of forces. By using a cable to transmit the spring force, we placed the torque generator on the person's back to reduce the weight on the legs. To test the effectiveness of the device, we performed a series of simulated lifting tasks and walking trials. When lifting a load of 10 kg in a squatting and stooping position, the device was able to reduce the activation of the erector spinae muscles by up to 41%. No significant change in the activation of the leg and back muscles was detected during walking.

Comparisons of Trunk Motions and Low Back Injury Risk between Alternative Hotel Room Cleaning Methods.

Hotel room cleaners frequently report job-related pain, with high rates of work-related musculoskeletal disorder injuries established for this group of workers. Surprisingly, there is limited published research documenting the impact of interventions to reduce ergonomic-related injury risks specific to hotel room cleaners' job tasks. In this study focused on hotel bathroom-cleaning and furniture-dusting tasks, twelve experienced hotel room cleaners used their standard method and a risk-reduction method-a tool with a handle that could extend, to perform these tasks. The female study participants' average age was 45.3 (SD 8.7) years with an average of 10 years of work experience as cleaners (range: 0.8-26.0 years). Trunk kinematics and a low back injury risk assessment were measured using the Lumbar Motion Monitor. All study metrics were significantly reduced when cleaning tasks involved use of adjustable, long-handled tools (p < 0.05). This study demonstrated that commonly available cleaning and dusting tools with extendable handles can significantly reduce low back injury risk among hotel room cleaners and potentially reduce injury risk to other body parts known to be the site of musculoskeletal disorders in this workforce. The study findings suggest that cleaning or housekeeping jobs in other industries where these same tasks are performed could benefit from use of extended-handle tools like those investigated here.

Biomechanics Analysis of the Firefighters' Thorax Movement on Personal Protective Equipment during Lifting Task Using Inertial Measurement Unit Motion Capture.

Back injury is a common musculoskeletal injury reported among firefighters (FFs) due to their nature of work and personal protective equipment (PPE). The nature of the work associated with heavy lifting tasks increases FFs' risk of back injury. This study aimed to assess the biomechanics movement of FFs on personal protective equipment during a lifting task. A set of questionnaires was used to identify the prevalence of musculoskeletal pain experienced by FFs. Inertial measurement unit (IMU) motion capture was used in this study to record the body angle deviation and angular acceleration of FFs' thorax extension. The descriptive analysis was used to analyze the relationship between the FFs' age and body mass index with the FFs' thorax movement during the lifting task with PPE and without PPE. Sixty-three percent of FFs reported lower back pain during work, based on the musculoskeletal pain questionnaire. The biomechanics analysis of thorax angle deviation and angular acceleration has shown that using FFs PPE significantly causes restricted movement and limited mobility for the FFs. As regards human factors, the FFs' age influences the angle deviation while wearing PPE and FFs' BMI influences the angular acceleration without wearing PPE during the lifting activity.

Factorial and Construct Validity of Sit-Up Test of Different Durations to Assess Muscular Endurance of Police Students

Background: The number of completed sit-ups in a given period of time is a commonly used assessment to measure trunk endurance in tactical populations. This study investigated factorial and construct validity of three different durations of a sit-up test—30 s, 60 s, and 120 s; Methods: Anthropometric characteristics and sit-ups performed for 30, 60, and 120 s by101 (♂: n = 62 and ♀: n = 39) police students were assessed. A factorial analysis was used to determine if three test durations group together in one factor, correlation analysis determined whether the sit-up tests were associated with anthropometric measures and whether the three variations in the test duration correlated between each other, and the Fisher’s transformation determined whether these correlations differed significantly; Results: All three sit-up variations loaded together into one factor in both sexes, providing factorial validity for all three test durations. Anthropometrics were associated with sit-up tests lasting 30 s in males and 120 s in females. A sit-up test lasting 60 s correlated significantly stronger to 120 s than to the 30 s sit-up test; Conclusions: The 60 s sit-up test seems to have the highest construct validity, as it was not affected by anthropometrics, and it may be an optimal choice for its lower risk of lower back injuries. By applying the results of this study, agencies could reduce the bias that may occur during the sit-up test and reduce the risk of injury during physical fitness assessment.

Towards the estimation of ultimate compression tolerance as a function of cyclic compression loading history: implications for lifting-related low back injury risk assessment

This study aimed to mathematically characterize the ultimate compression tolerance (UCT) as a function of spinal joint posture, loading variation, and loading duration. One hundred and fourteen porcine cervical spinal units were tested. Spinal units were randomly assigned to subthreshold cyclic loading groups that differed by joint posture (neutral, flexed), peak loading variation (10%, 20%, 40%), and loading duration (1000, 3000, 5000 cycles). After the assigned conditioning test, UCT testing was ­performed. Force and actuator position were sampled at 100 Hz. A three-­dimensional relationship between UCT, loading variation, and loading duration was most accurately characterized by a second order polynomial surface (R2 = 0.644, RMSE = 1.246 kN). However, distinct UCT responses were observed for flexed and neutral postures. A single second-order polynomial most accurately characterized the UCT – loading duration relationship (R2 = 0.905, RMSE = 0.718 kN) for flexed postures. For neutral joint postures, separate second-order polynomial equations were developed to characterize the UCT – loading duration relationship for each variation group (R2 = 0.618–0.906, RMSE = 0.617 kN–0.746 kN). These findings suggest that UCT responses are influenced by joint posture and these data may be used to inform ergonomic tools for the assessment of low back injury risk during occupational lifting.

Adjustments in Shoulder and Back Kinematics during Repetitive Palletizing Tasks.

Repetitive task performance is a leading cause of musculoskeletal injuries among order-picking workers in warehouses. The repetition of lifting tasks increases the risk of back and shoulder injuries among these workers. While lifting in this industry is composed of loaded and unloaded picking and placing, the existing literature does not address the separate analysis of the biomechanics of the back and shoulder for these events. To that end, we investigated the kinematics of the back and shoulder movements of nine healthy male participants who performed three sessions of a simulated de/palletization task. Their back and shoulder kinematics were sensed using an optical motion capture system to determine the back inclination and shoulder flexion. Comparison of the kinematics between the first and last sessions indicated statistically significant changes in the timings, angles, coordination between the back and shoulder, and moments around the shoulder (). The majority of the significant changes were observed during the loaded events, which confirms the importance of the separation of these events for biomechanical analysis. This finding suggests that focusing worker evaluation on the loaded periods can provide important information to detect kinematic changes that may affect musculoskeletal injury risk.

Validating an inertial measurement unit for cricket fast bowling: a first step in assessing the feasibility of diagnosing back injury risk in cricket fast bowlers during a tele-sport-and-exercise medicine consultation.

This study aimed to validate an array-based inertial measurement unit to measure cricket fast bowling kinematics as a first step in assessing feasibility for tele-sport-and-exercise medicine. We concurrently captured shoulder girdle relative to the pelvis, trunk lateral flexion, and knee flexion angles at front foot contact of eight cricket medium-fast bowlers using inertial measurement unit and optical motion capture. We used one sample t-tests and 95% limits of agreement (LOA) to determine the mean difference between the two systems and Smallest Worth-while Change statistic to determine whether any differences were meaningful. A statistically significant (p < 0.001) but small mean difference of −4.7° ± 8.6° (95% Confidence Interval (CI) [−3.1° to −6.4°], LOA [−22.2 to 12.7], SWC 3.9°) in shoulder girdle relative to the pelvis angle was found between the systems. There were no statistically significant differences between the two systems in trunk lateral flexion and knee flexion with the mean differences being 0.1° ± 10.8° (95% CI [−1.9° to 2.2°], LOA [−22.5 to 22.7], SWC 1.2°) and 1.6° ± 10.1° (95% CI [−0.2° to 3.3°], LOA [−19.2 to 22.3], SWC 1.9°) respectively. The inertial measurement unit-based system tested allows for accurate measurement of specific cricket fast bowling kinematics and could be used in determining injury risk in the context of tele-sport-and-exercise-medicine.

Patterns of Intervertebral Disk Alteration in Asymptomatic Elite Rowers: A T2* MRI Mapping Study.

Background:Repetitive loading of the back puts elite rowers at risk for acute and chronic back injuries.Hypothesis:That asymptomatic elite rowers would demonstrate characteristic intervertebral disk (IVD) alterations on T2* magnetic resonance imaging (MRI) mapping compared with asymptomatic nonrowers.Study Design:Cross-sectional study; Level of evidence, 3.Methods:This study included 20 asymptomatic elite rowers (mean age, 23.4 ± 3.03 years; 9 women, 11 men) studied at 2 different times, once before (t 1) and once after (t 2) the competition phase. MRI including T2* mapping was performed on a 3-T scanner. The authors derived normative T2* data from a previous study on 40 asymptomatic volunteers (20 men, 20 women) who were not competitive rowers; based on complete T2* data sets, 37 controls were included. T2* values were compared between groups in 4 lumbar IVDs, and midsagittal T2* values were compared in 5 zones: anterior annulus fibrosus (AF), anterior nucleus pulposus (NP), central NP, posterior NP, and posterior AF. The Pfirrmann grade was used for morphological assessment of disk degeneration. Statistical analysis was conducted using the Mann-Whitney U test, Wilcoxon matched-pairs test, and Spearman rank correlation coefficient.Results:Lower T2* values were noted in the rower group compared with the controls (37.08 ± 33.63 vs 45.59 ± 35.73 ms, respectively; P < .001). The intersegmental comparison revealed lower mean T2* values among rowers (P ≤ .027 for all). The interzonal comparison indicated significantly lower mean T2* values for the rowers in all zones except for the anterior NP (P ≤ .008 for all). Lower mean T2* values were observed for the rowers at t 1 versus t 2 (39.25 ± 36.19 vs 43.97 ± 38.67 ms, respectively; P = .008). The authors noted a higher level of IVD damage according to Pfirrmann assessment in the rower cohort (P < .001); the Pfirrmann grade distributions of rowers versus controls, respectively, were as follows: 51.3% versus 73.7% (grade 1), 20.5% versus 19.5% (grade 2), 21.8% versus 6.8% (grade 3), 5.1% versus 0% (grade 4), and 1.3% versus 0% (grade 5). The authors also noted a correlation between low T2* and high Pfirrmann grade at t 1 (r =–0.48; P < .001) and t 2 (r =–0.71; P < .001).Conclusion:The cohort of elite rowers revealed more degenerative IVD changes compared with controls. The T2* values suggest that repetitive loading of the spine has demonstrable short-term and possibly permanent effects on the lumbar IVD.