Modifying bowling kinematics in cricket pace bowlers with exercise-based injury prevention: A cluster-randomised controlled trial.

OBJECTIVES: Undesirable bowling kinematics can increase the risk of low back injury. This study investigated if an exercise-based injury prevention program (IPP) could modify bowling kinematics in community-level adolescent pace bowlers. DESIGN: Cluster-randomised controlled trial. METHODS: Pace bowlers from eight cricket organisations were cluster-randomised into an intervention or control group. At baseline and follow-up sessions biomechanical bowling data were collected. Between sessions, the intervention group completed an eight-week IPP while the control continued their normal cricket activity. Treatment effects (95% CI) were estimated with linear mixed models. RESULTS: There were significant treatment effects favouring the intervention group for shoulder counter-rotation (-3.8°; -7.2° to -0.3°) and lateral trunk flexion relative to the pelvis (-2.2°; -4.0° to -0.5°). Shoulder counter-rotation also increased in the control group by 2.2° (Cohen's d=0.22). There were no effects of the intervention on: lateral trunk flexion at front foot contact (FFC) (1.2°; -2.5° to 4.8°), lateral trunk flexion at ball release (BR) (-0.5°; -3.0° to 2.0°), pelvis rotation at FFC (0.9°; -4.0° to 2.2°), pelvis rotation at BR (-1.1°; -5.7° to 3.6°), front hip angle at FFC (1.6°; -3.6° to 6.7°), front hip angle at BR (-1.6°; -5.0° to 1.9°), front knee angle at FFC (-1.1°; -4.5° to 2.3°), front knee angle at BR (1.7°; -5.6° to 9.1°), or ball velocity (1.1kmh-1; -7.5kmh-1 to 9.7kmh-1). CONCLUSIONS: The IPP maintained shoulder counter-rotation and lateral trunk flexion relative to the pelvis in the intervention group and this could attenuate injury risk. No treatment effects were observed for lower-limb kinematics.

Submaximal Cricket Fast Bowling Offers a Disproportionate Reduction in Loading Versus Performance: An Alternative Workload Intervention.

CONTEXT: Cricket fast bowlers are particularly susceptible to lumbar spine loading and injury. Quantitative analysis of technique typically involves laboratory-based biomechanical systems with limited ecological validity, whereas contemporary developments in global positioning satellite microtechnologies facilitate an on-field evaluation of loading. OBJECTIVE: To quantify the influence of submaximal bowling from reduced approach lengths on performance and loading. DESIGN: Repeated-measures, field-based design. SETTING: Regulation cricket pitch. PARTICIPANTS: A total of 12 male cricket academy fast bowlers (18.7 [0.7] y), injury free with ≥3 years of competitive experience. INTERVENTIONS: Each bowler wore 2 global positioning satellite units placed at C7 and L4 to measure triaxial acceleration (100 Hz). Bowlers completed an over (6 deliveries) from a randomized 3-, 6-, 9-, and 12-stride approach. MAIN OUTCOME MEASURES: Ball speed was recorded as the performance measure, with PlayerLoad in the anteroposterior, mediolateral, and vertical planes also calculated for each delivery length. RESULTS: In ball speed, there was a significant main effect for delivery length (P = .02), with a 3-stride approach eliciting significantly less ball speed than a 9-stride (P = .03) or 12-stride (P = .002) approach. In loading, there was a significant main effect for delivery length (P < .001) in the anteroposterior, mediolateral, and vertical planes, with loading increasing linearly as a function of delivery strides. The 6-stride approach elicited a 44% reduction in loading, with a disproportionately small 3.5% decrease in performance. There was a significant main effect for global positioning satellite location (P ≤ .023) in all planes, with L4 eliciting greater loading than C7. CONCLUSIONS: A submaximal 6-stride approach yielded the optimum balance between reduced loading and performance inhibition. Reduced delivery length, therefore, offers an alternative to reduced overs in reducing loading in young bowlers and might also have practicable value in the rehabilitation of bowlers postinjury.

The influence of age on quality of life after upper body burn.

BACKGROUND: In Spain, the number of aged persons is increasing. By the year 2066, it is expected that 34.6% of the Spanish population will be over 65 years of age. Elderly people present a higher burning risk owing in part to impaired balance and decreased physical strength, lower cognitive abilities, or socioeconomic context. OBJECTIVE: Burns to the upper body body are common and affect both emotional state and physical function, thus leading to reduced quality of life (QoL). Our objective was to determine the influence of age on the QoL of patients who experienced burns to the upper body, with burns with 2 years. METHODS: This is an observational study with a sample of 58 patients with burns only on the upper body. Patients were divided into two groups: 29 patients of age over 65 years and 29 patients under 65 years; all of them attended the Vall d'Hebron Burn Center, Barcelona, between 2011 and 2014. From the original sample, 45 patients had survived by the time the information was gathered. The QoL of these individuals was evaluated with the Spanish version of the Burn Specific Health Scale. Demographic data (sex, age, total burn surface area [TBSA], burn mechanism, pathological history, length of hospital stay, and rehabilitation duration) were collected. Statistical analysis included parametric and nonparametric tests as appropriate with R3.3.3. RESULTS: There were no differences between groups regarding the mechanism of burn, TBSA, length of hospital stay, and the domains of QoL test. High blood pressure, diabetes, and other comorbidities were significantly more common in the elderly group than in the younger group. Eleven patients died in the elderly group and two in the younger group (p=0.012). CONCLUSION: As opposed to what could be expected, in this study, there were no significant differences between surviving patients in both age groups in terms of perceived QoL. Nevertheless, mortality after a burn in the upper side of the body was significantly higher in elderly people than in younger people. The present study results do not support the use of different rehabilitation approaches in elderly patients.

Do Older Adults and Those Recovered from Low Back Injury Share Common Muscle Activation Adaptations?

Theoretical models suggest trunk muscle activation compensates for spinal systems impairments. The purpose of this study was to determine if two populations (older adults and those recovered from a lower back injury (rLBI)) with spinal system impairments have similar muscle activation patterns to each other, but differ from controls. Trunk electromyograms collected from 12 older adults, 16 rLBI, and 19 controls during two dynamic tasks showed that older adults and rLBI had higher activation amplitudes, sustained temporal and more synergistic activation relative to controls. However, differences found between older adults and rLBI suggest that spinal system impairments differed between groups or that recent pain (rLBI) uniquely influenced muscle activation. This sheds light on our understanding of the relationship between spinal system impairments and muscle activation.

Musculoskeletal Demands in Violin and Viola Playing: A Literature Review.

BACKGROUND/AIMS: Research in music medicine has reported incidence rates of musculoskeletal disorders of approx. 70% in instrumental musicians. String players have the highest risk, with rates of performance-related musculoskeletal disorders (PRMDs) of 65% to 88%. Playing the violin or viola requires complex neuromusculoskeletal skills, and the high frequency of repetitive movements, dynamic and static muscle load, awkward postures, poor technique, and practice time are factors causing musculoskeletal strain. In ergonomic terms, these disorders can be categorized based on extrinsic and intrinsic loads. Identification of intrinsic loads, such as muscle utilization and joint motion, is necessary to understand factors influencing musculoskeletal disorders associated with violin playing. The aim of this study was to review the literature on musculoskeletal demands in violin and viola playing. METHODS: A literature search was conducted in the PubMed, COCHRANE, and CINAHL electronic databases from 1999 to 2015 using the search terms violin, viola, high strings, movement, posture, and synonyms. A manual search of Medical Problems of Performing Artists was also conducted. Additional references were identified by searching the citations and reference lists of all identified relevant studies. RESULTS: The results suggest that an asymmetric playing posture, the associated muscle activity, and joint mobility may contribute to musculoskeletal problems in violin and viola players. Evidence suggests an increased load of intrinsic factors in violin/viola performance. CONCLUSION: The identification of intrinsic loads in violin and viola playing may facilitate the development of prevention strategies and interventions.

Shoulder and Lower Back Joint Reaction Forces in Seated Double Poling.

Overuse injuries in the shoulders and lower back are hypothesized to be common in cross-country sit-skiing. Athletes with reduced trunk muscle control mainly sit with the knees higher than the hips (KH). To reduce spinal flexion, a position with the knees below the hips (KL) was enabled for these athletes using a frontal trunk support. The aim of the study was to compare the shoulder joint (glenohumeral joint) and L4-L5 joint reactions of the KL and KH sitting positions. Five able-bodied female athletes performed submaximal and maximal exercise tests in the sitting positions KL and KH on a ski ergometer. Measured pole forces and 3-dimensional kinematics served as input for inverse-dynamics simulations to compute the muscle forces and joint reactions in the shoulder and L4-L5 joint. This was the first musculoskeletal simulation study of seated double poling. The results showed that the KH position was favorable for higher performance and decreased values of the shoulder joint reactions for female able-bodied athletes with full trunk control. The KL position was favorable for lower L4-L5 joint reactions and might therefore reduce the risk of lower back injuries. These results indicate that it is hard to optimize both performance and safety in the same sit-ski.

Assessment of low back disorders risk based on allowable weight limits for manual lifting in Iran.

In 2011, load limits for manual lifting were adopted in Iran to protect workers from low back injury without prior testing of accuracy with Iranian workers. This investigation examined how accurate the adopted ACGIH TLVs at the allowable limits predict risk for LBP disorders for a group of Iranian workers using biomechanical criteria. Testing took place in the laboratory with participants completing a series of 2-handed lifting tasks as defined in the Iranian Guideline for Manual Lifting. To test accuracy, both compression and shear forces were estimated for fifteen male Iranian workers who completed 25 lift combinations that varied in height and reach with the maximal allowable load. The findings, when compared to a risk threshold of 3400 N compression and 700 N shear, showed above-threshold forces for compression and little-to-no safety margins with repetitive lifting for most lifts at torso height and below. Since Government, employers and workers use these guidelines to decide on work/workplace design; these guidelines require further review and revision based on the anthropometrics of Iranian people.

Supervisor and Organizational Factors Associated with Supervisor Support of Job Accommodations for Low Back Injured Workers.

Purpose Temporary job accommodations contribute to the prevention of chronic work disability due to low back pain (LBP) through the facilitation of early return to work; yet, workplace dimensions of job accommodation are poorly understood. The objective of this study was to determine supervisor and organizational factors associated with supervisors' support for temporary job accommodations for LBP injured workers. Methods Supervisors were recruited from 19 workplaces in the USA and Canada and completed an online survey regarding job accommodation practices and potential associated factors with respect to a case vignette of a worker with LBP. Multivariable linear regression was used to identify the most parsimonious set of factors associated with supervisors' support for accommodations. Results A total of 804 supervisors participated with 796 eligible for inclusion in the analysis. The final set of factors explained 21 % of the variance in supervisors' support for temporary job accommodations. Considerate leadership style (ß = 0.261; 95 % CI 0.212, 0.310), workplace disability management policies and practices (ß = 0.243; 95 % CI 0.188, 0.298), and supervisor autonomy for designing and providing workplace accommodations (ß = 0.156; 95 % CI 0.071, 0.241) had the largest effect on supervisor support for accommodations. Conclusion Factors predicting supervisors' likelihood to accommodate LBP injured workers include use of considerate leadership style, workplace disability management policies and practices, and supervisor autonomy. Workplace interventions targeting these factors should be developed and evaluated for their ability to improve work disability prevention outcomes.

Quantification of Training Load During Return to Play After Upper- and Lower-Body Injury in Australian Rules Football.

CONTEXT: Training volume, intensity, and distribution are important factors during periods of return to play. PURPOSE: To quantify the effect of injury on training load (TL) before and after return to play (RTP) in professional Australian Rules football. METHODS: Perceived training load (RPE-TL) for 44 players was obtained for all indoor and outdoor training sessions, while field-based training was monitored via GPS (total distance, high-speed running, mean speed). When a player sustained a competition time-loss injury, weekly TL was quantified for 3 wk before and after RTP. General linear mixed models, with inference about magnitudes standardized by between-players SDs, were used to quantify effects of lower- and upper-body injury on TL compared with the team. RESULTS: While total RPE-TL was similar to the team 2 wk before RTP, training distribution was different, whereby skills RPE-TL was likely and most likely lower for upper- and lower-body injury, respectively, and most likely replaced with small to very large increases in running and other conditioning load. Weekly total distance and high-speed running were most likely moderately to largely reduced for lower- and upper-body injury until after RTP, at which point total RPE-TL, training distribution, total distance, and high-speed running were similar to the team. Mean speed of field-based training was similar before and after RTP compared with the team. CONCLUSIONS: Despite injured athletes' obtaining comparable TLs to uninjured players, training distribution is different until after RTP, indicating the importance of monitoring all types of training that athletes complete.

Management of Acute Lumbar Injuries in the Workplace.

Occupational acute lumbar injuries are a common injury. One intervention that is unique to occupational health is the determination of the amount of physical activity that an injured worker can perform without increasing the risk of further injury. Clinical recommendations suggest that workers continue to stay active; however, it is still the clinician's responsibility to determine the level of activity. The level of work activity is determined on a case-to-case basis and is done by evaluating the physical capacity of an injured worker and the job description. Current evidence-based guidelines suggest that staying active may actually reduce pain levels. The purpose of this evidence-based literature review is to outline the proper assessment and management of workers who have sustained a work-related low back injury. The related literature has been reviewed as well as red flags for more severe neurological conditions that require more in-depth evaluation. Determining the safe level of activity and guided return to work have been discussed.

Choosing appropriate comparison group participants in studies of veterans: Characteristics of orthopedically injured and uninjured Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn veterans.

INTRODUCTION: Research addressing deployment-related traumatic brain injury (TBI) is fairly complex due to a high prevalence of comorbid conditions, multiple exposures, and the lack of acute medical records. Therefore, there is a need for a well-defined, matching comparison group. This study compared deployment-related characteristics, everyday functioning, and cognitive performance in recently deployed veterans who had not sustained any injuries with those who had orthopedic injuries during deployment, but who were without a history of TBI. METHOD: Participants included 45 individuals who had been deployed and who were without injuries and a group of 27 individuals who reported at least one orthopedic injury during deployment. The Mayo-Portland Adaptability Inventory-4, Community Integration Questionnaire, Veterans RAND 36 Item Health Survey, Brief Pain Inventory, Barratt Impulsiveness Scale-11, and posttraumatic stress disorder (PTSD) Checklist-Civilian (PCL-C) were used to assess daily functioning. Cognitive performance was measured using the Controlled Oral Word Association Test, Trail Making Test, Color-Word Interference Test, and Verbal Selective Reminding Test. The two groups were compared using t tests based on equal variances. The effect size was calculated. RESULTS: There were no between-group differences, with all variables having p-values >.1 and small to medium effect sizes. DISCUSSION: Orthopedic injuries sustained during deployment that did not require evacuation or hospitalization did not have any lasting effect on participants' health, cognition, and daily functioning relative to other deployed individuals with no history of injury. These results indicate the two groups are comparable and that their data could be potentially combined to create a single comparison group. Due to the small sample available for this study, the current results are considered preliminary, and further investigation is needed.

The Biomechanics of the Modern Golf Swing: Implications for Lower Back Injuries.

The modern golf swing is a complex and asymmetrical movement that places an emphasis on restricting pelvic turn while increasing thorax rotation during the backswing to generate higher clubhead speeds at impact. Increasing thorax rotation relative to pelvic rotation preloads the trunk muscles by accentuating their length and allowing them to use the energy stored in their elastic elements to produce more power. As the thorax and pelvis turn back towards the ball during the downswing, more skilled golfers are known to laterally slide their pelvis toward the target, which further contributes to final clubhead speed. However, despite the apparent performance benefits associated with these sequences, it has been argued that the lumbar spine is incapable of safely accommodating the forces they produce. This notion supports a link between the repeated performance of the golf swing and the development of golf-related low back injuries. Of the complaints reported by golfers, low back injuries continue to be the most prevalent, but the mechanism of these injuries is still poorly understood. This review highlights that there is a paucity of research directly evaluating the apparent link between the modern golf swing and golf-related low back pain. Furthermore, there has been a general lack of consensus within the literature with respect to the methods used to objectively assess the golf swing and the methods used to derived common outcome measures. Future research would benefit from a clear set of guidelines to help reduce the variability between studies.

Lumbar spinal loading during bowling in cricket: a kinetic analysis using a musculoskeletal modelling approach.

The objective of the study was to evaluate two types of cricket bowling techniques by comparing the lumbar spinal loading using a musculoskeletal modelling approach. Three-dimensional kinematic data were recorded by a Vicon motion capture system under two cricket bowling conditions: (1) participants bowled at their absolute maximal speeds (max condition), and (2) participants bowled at their absolute maximal speeds while simultaneously forcing their navel down towards their thighs starting just prior to ball release (max-trunk condition). A three-dimensional musculoskeletal model comprised of the pelvis, sacrum, lumbar vertebrae and torso segments, which enabled the motion of the individual lumbar vertebrae in the sagittal, frontal and coronal planes to be actuated by 210 muscle-tendon units, was used to simulate spinal loading based on the recorded kinematic data. The maximal lumbar spine compressive force is 4.89 ± 0.88BW for the max condition and 4.58 ± 0.54BW for the max-trunk condition. Results showed that there was no significant difference between the two techniques in trunk moments and lumbar spine forces. This indicates that the max-trunk technique may not increase lower back injury risks. The method proposed in this study could be served as a tool to evaluate lower back injury risks for cricket bowling as well as other throwing activities.

Lower limb reaction force asymmetry in rowers with and without a history of back injury.

Back injury is common in rowers. Asymmetrical lower limb reaction force on the foot stretchers during rowing may compromise trunk biomechanics and lead to back injury. However, such a mechanism remains putative. Therefore, this study examined lower limb reaction force in experienced rowers with and without a history of back injury. Six rowers who suffered from back injury for more than one week in the past year and another 19 rowers who were never injured performed maximal exertion rowing on a fixed-head rowing machine for 30 strokes. Peak force, average and peak loading rate of the lower limb reaction force during the middle 10-stroke were recorded using strain-gauge transducers placed at the foot stretchers. Asymmetries and intra-limb variability were quantified as asymmetry indices and coefficients of variation, respectively. No significant asymmetry was observed in all selected kinetic parameters between the injured and healthy rowers (p = 0.448-0.722, Hedges' g = 0.162-0.310). Subgroup analyses also did not reveal any significant kinetic differences between injured and healthy scullers or sweepers (p = 0.194-0.855, Hedges' g = 0.203-0.518). Rowers with a history of back injury, regardless of the rowing types, did not demonstrate greater lower limb reaction force asymmetry when compared with healthy rowers.

Potential Mechanisms Leading to Overuse Injuries of the Back in Alpine Ski Racing: A Descriptive Biomechanical Study.

BACKGROUND: Overuse injuries of the back are a common complaint among top athletes and of competitive alpine skiers in particular. However, there is limited understanding about the sport-specific causes of these injuries that is essential for their prevention. PURPOSE/HYPOTHESIS: This study was undertaken to describe the sport-specific, overall trunk kinematics and skiers' loading during giant slalom turns and to assess the plausibility of the hypothesis that a combination of frontal bending, lateral bending, and/or torsion in the loaded trunk might be a potential mechanism leading to overuse injuries of the back in alpine ski racing. STUDY DESIGN: Descriptive laboratory study. METHODS: Eight European Cup-level athletes performed giant slalom runs with 2 different pairs of skis (varying in length, width, and sidecut). They were analyzed with respect to selected kinematic variables related to spinal disc loading. The overall trunk movement components (frontal bending, lateral bending, and torsion) were measured using 2 inertial measurement units fixed on the sacrum and sternum. Total ground-reaction forces were measured by pressure insoles. RESULTS: During the turn phase in which the total ground-reaction forces were the greatest (up to 2.89 times the body weight), the highest average values of frontal bending (38.7°), lateral bending (14.7°), and torsion (7.7°) in the trunk occurred. Similar magnitudes were observed when skiing on longer, giant slalom skis with less width and sidecut. CONCLUSION: The typical loading patterns of the back in alpine ski racing include a combined occurrence of frontal bending, lateral bending, and torsion in the loaded trunk. Because these factors are known to be related to high spinal disc loading, they may be considered important components of mechanisms leading to overuse injuries of the back in alpine ski racing. CLINICAL RELEVANCE: Prevention measures should aim to control and/or reduce the magnitude of frontal bending, lateral bending, and torsion in the trunk, as well as the peak loads, while skiing.

Reported load carriage injuries of the Australian army soldier.

INTRODUCTION: Many injuries experienced by soldiers can be attributed to the occupational loads they are required to carry. PURPOSE: The aim of this study was to determine whether contemporary military load carriage is a source of injuries to Australian Regular Army soldiers and to profile these injuries. METHODS: The Australian Defence Force 'Occupational Health, Safety and Compensation Analysis and Reporting' database was searched to identify all reported injuries sustained during load carriage events. Key search terms were employed and narrative description fields were interrogated to increase data accuracy. RESULTS: A total of 1,954 injury records were extracted from the database. Of these, 404 injuries were attributed to load carriage. The majority of these load carriage injuries involved either the lower limb or back, with bones and joints accounting for the most frequently reported body structures to be injured. Field activities were the leading activities being performed at the time that load carriage injuries occurred, and muscular stress was identified as the mechanism of injury for over half of reported load carriage injuries. CONCLUSION: This study suggests that load carriage is a substantial source of injury risk to Australian Army soldiers. Physical training may fail to adequately prepare soldiers for load carriage tasks during field training exercises.

Differences in lumbopelvic control and occupational behaviours in female nurses with and without a recent history of low back pain due to back injury.

Low back pain is highly prevalent in nurses. This study aimed to determine which physical fitness, physical activity (PA) and biomechanical characteristics most clearly distinguish between nurses with [recently injured (RInj)] and without [not recently injured (NRInj)] a recent back injury. Twenty-seven (8 RInj, 19 NRInj) female nurses completed questionnaires (pain, work, PA), physical fitness, biomechanical and low back discomfort measures, and wore an accelerometer for one work shift. Relative to NRInj nurses, RInj nurses exhibited reduced lumbopelvic control (41.4% more displayed a moderate loss of frontal plane position), less active occupational behaviours (less moderate PA; less patient lifts performed alone; more sitting and less standing time) and more than two times higher low back discomfort scores. Despite no physical fitness differences, the lumbopelvic control, occupational behaviours and discomfort measures differed between nurses with and without recent back injuries. It is unclear whether poor lumbopelvic control is causal or adaptive in RInj nurses and may require further investigation. Practitioner Summary: It is unclear which personal modifiable factors are most clearly associated with low back pain in nurses. Lumbopelvic control was the only performance-based measure to distinguish between nurses with and without recent back injuries. Future research may investigate whether reduced lumbopelvic control is causal or adaptive in recently injured nurses.

The club-level road cyclist: injury, pain, and performance.

OBJECTIVE: The aims of this study were to (1) examine riding habits of injured cyclists, (2) identify factors related to seeking medical treatment, (3) investigate performance of recreational road cyclists compared with established norms regarding strength and flexibility measures, and (4) propose cycling-specific injury risk factors. DESIGN: Observational and prospective study. SETTING: Cycling store and bicycle distribution company. PARTICIPANTS: Sixty-three experienced road cyclists. ASSESSMENT OF RISK FACTORS: Initial data collection included a questionnaire. A 2-week training diary and 8 weekly follow-up injury questionnaires were also collected. MAIN OUTCOME MEASURES: Training habits and injury history, bike fit, flexibility, and isometric, dynamic, and plyometric strength measures. RESULTS: Participants were likely to have an injury at baseline, and chronic pain was common. Cyclists trained for an equal quantity of time irrespective of experiencing pain. Injury severity in terms of pain level and participant age were factors in seeking medical care. Our participants performed poorly on our testing protocol compared with available norms. Flexibility, strength, and bike fit measures did not predict injury. Previous injury predicted prospective injury. The knee and lumbar region were most frequently injured. CONCLUSIONS: Cycling is a sport in which injury risk and prevention need to be further studied. Cyclists are frequently injured but continue to participate in cycling at volumes equal to their healthy peers. CLINICAL RELEVANCE: This study outlines a clinically reproducible cyclist assessment and discusses behaviors common to the cycling patient.

Reduction of spinal loads through adjustable interventions at the origin and destination of palletizing tasks.

OBJECTIVE: This article evaluates the effectiveness of two interventions: a self-leveling pallet carousel designed to position the loads vertically and horizontally at origin, and an adjustable cart designed to raise loads vertically at destination to reduce spine loads. BACKGROUND: Low back disorders among workers in manual material handling industries are very prevalent and have been linked to manual palletizing operations. Evidence into the effectiveness of ergonomic interventions is limited, with no research that investigates interventions with adjustable load location. METHOD: Thirteen males experienced in manual material handling participated in simulated order selecting tasks where spine loads were quantified for each intervention condition: carousel to traditional cart, pallet to traditional cart, pallet to adjustable cart, and carousel to adjustable cart. RESULTS: The results showed that combining both devices results in reduction in spine compression (61%), anterior-posterior shear (72%), and lateral shear (63%) compared to traditional palletizing conditions. Individually, the carousel was responsible for the greatest reductions, but the lowest values were typically achieved by combining the adjustable cart and carousel. CONCLUSION: The combination of the interventions (self-leveling carousel and adjustable cart) was most effective in reducing the spine loads when compared to the traditional pallet-cart condition. The individual interventions also reduced the loads compared to the traditional condition. APPLICATION: With de-palletizing/palletizing tasks being a major source of low back injuries, the combination of self-leveling carousel and adjustable cart has been found to be effective in reducing the peak spine loading as compared to traditional pallet on floor and nonadjustable flat cart conditions.

Preflight screening techniques for centrifuge-simulated suborbital spaceflight.

INTRODUCTION: Historically, space has been the venue of the healthy individual. With the advent of commercial spaceflight, we face the novel prospect of routinely exposing spaceflight participants (SPFs) with multiple comorbidities to the space environment. Preflight screening procedures must be developed to identify those individuals at increased risk during flight. We examined the responses of volunteers to centrifuge accelerations mimicking commercial suborbital spaceflight profiles to evaluate how potential SFPs might tolerate such forces. We evaluated our screening process for medical approval of subjects for centrifuge participation for applicability to commercial spaceflight operations. METHODS: All registered subjects completed a medical questionnaire, physical examination, and electrocardiogram. Subjects with identified concerns including cardiopulmonary disease, hypertension, and diabetes were required to provide documentation of their conditions. RESULTS: There were 335 subjects who registered for the study, 124 who completed all prescreening, and 86 subjects who participated in centrifuge trials. Due to prior medical history, five subjects were disqualified, most commonly for psychiatric reasons or uncontrolled medical conditions. Of the subjects approved, four individuals experienced abnormal physiological responses to centrifuge profiles, including one back strain and three with anxiety reactions. DISCUSSION: The screening methods used were judged to be sufficient to identify individuals physically capable of tolerating simulated suborbital flight. Improved methods will be needed to identify susceptibility to anxiety reactions. While severe or uncontrolled disease was excluded, many subjects successfully participated in centrifuge trials despite medical histories of disease that are disqualifying under historical spaceflight screening regimes. Such screening techniques are applicable for use in future commercial spaceflight operations.