Comparison of Slip Training in VR Environment And on Moveable Platform.

Slip training is gaining popularity as an innovative fall intervention approach. The objective of this study was to compare the efficacy of two different slip training modality (moveable platform and virtual reality) in reducing fall frequency and improving reactive recovery in older adults. Thirty-six healthy older adults were involved in a laboratory study, and were equally and randomly divided into the control group, the moveable platform training (MPT) group, and the virtual reality training (VRT) group. The MPT was achieved by inducing slips using a custom built sliding device consisting of a low friction, motorized moveable platform. The VRT was conducted by inducing visual perturbation in a head mounted display while subjects walked on a treadmill. All groups performed slip trials (kinematics, kinetics and EMG data were collected) on an actual slippery floor surface before and after a training session. The results indicated a significant reduction in fall frequency in both training groups. Between MPT and VRT groups, significant differences were also found in forward trunk rotations, peak knee angular velocity, ankle coactivity, and muscular activity in tibialis anterior. It was concluded that slip training in VR environment could produce comparable results in fall intervention.

EMG and kinematic responses to unexpected slips after slip training in virtual reality.

The objective of the study was to design a virtual reality (VR) training to induce perturbation in older adults similar to a slip and examine the effect of the training on kinematic and muscular responses in older adults. Twenty-four older adults were involved in a laboratory study and randomly assigned to two groups (VR training and control). Both groups went through three sessions including baseline slip, training, and transfer of training on slippery surface. The training group experienced 12 simulated slips using a visual perturbation induced by tilting a VR scene while walking on the treadmill and the control group completed normal walking during the training session. Kinematic, kinetic, and electromyography data were collected during all the sessions. Results demonstrated the proactive adjustments such as increased trunk flexion at heel contact after training. Reactive adjustments included reduced time to peak activations of knee flexors, reduced knee coactivation, reduced time to trunk flexion, and reduced trunk angular velocity after training. In conclusion, the study findings indicate that the VR training was able to generate a perturbation in older adults that evoked recovery reactions and such motor skill can be transferred to the actual slip trials.

Effects of perturbation-based slip training using a virtual reality environment on slip-induced falls.

The purpose of the current study was to design and evaluate the effectiveness of virtual reality training in improving recovery reactions and reducing fall frequency in older adults. Twenty-four older adults were recruited and randomly assigned to two groups (virtual reality training and control). Both groups underwent three sessions including baseline slip, training and transfer of training on slippery surface. Both groups experienced two slips, one during baseline and the other during the transfer of training trial. The training group underwent 12 simulated slips using a visual perturbation induced by tilting a virtual reality scene while walking on the treadmill and the control group performed normal walking during the training session. Kinematic and kinetic data were collected during all the sessions. Results demonstrated a reduced incidence of falls in the training group during the transfer of training trial as compared to the control group. The training group was able to transfer reactive control strategies learned during training to the second slip trial. The reactive adjustments included reduced slip distance. Additionally, gait parameters reflective of gait instability (stride length, step width, variability in stride velocity) reduced after walking in the VR environment for 15-20 min. The results indicated a beneficial effect of the virtual reality training in reducing slip severity and recovery kinematics in healthy older adults.

Associations between psychosocial risk factors and musculoskeletal disorders: application to the IT profession in India.

The exponential growth of the information technology (IT) industry in India has been accompanied with a substantial increase in the reporting of work-related musculoskeletal disorders (WMSDs). The purpose of the current study was to identify and assess the contributions of prevalent psychosocial factors on perceived WMSD outcomes among IT professionals from India. About 77 IT professionals from India completed a survey set consisting of 26 question items from the Job Content Questionnaire and 3 separate question items pertaining to WMSD outcomes (pain/discomfort and psychological stress scores). The findings suggest prevalence of existing pain (shoulder/neck and low back) in more than one-fourth of the respondents. Additionally two-thirds of the respondents had never had any ergonomics awareness training. Co-worker support and psychological work demands were found to be the strongest contributors of psychosocial risk factors towards pain/discomfort and psychological stress outcomes. Findings from this study highlight the influence of certain psychosocial traits of the Indian IT workplace on perceived WMSD outcomes. There is a need to develop and implement intervention strategies to address these factors that may help lower the risk of work-related musculoskeletal pain.

Effects of moveable platform training in preventing slip-induced falls in older adults.

Identifying effective interventions is vital in preventing slip-induced fall accidents in older adults. The purpose of the current study was to evaluate the efficacy of moveable platform training in improving recovery reactions and reducing fall frequency in older adults. Twenty-four older adults were recruited and randomly assigned to two groups (training and control). Both groups underwent three sessions including baseline slip, training, and transfer of training on a slippery surface. Both groups experienced two slips on a slippery surface, one during the baseline and the other (after 2 weeks) during the transfer of training session. In the training session, the training group underwent twelve simulated slips using a moveable platform while the control group performed normal walking trials. Kinematic, kinetic, and EMG data were collected during all the sessions. Results indicated a reduced incidence of falls in the training group during the transfer of training trial as compared to the control group. The training group was able to transfer proactive and reactive control strategies learned during training to the second slip trial. The proactive adjustments include increased center-of-mass velocity and transitional acceleration after training. Reactive adjustments include reduction in muscle onset and time to peak activations of knee flexors and ankle plantar flexors, reduced ankle and knee coactivation, reduced slip displacement, and reduced time to peak knee flexion, trunk flexion, and hip flexion velocities. In general, the results indicated a beneficial effect of perturbation training in reducing slip severity and recovery kinematics in healthy older adults.

Workstyle risk factors for work related musculoskeletal symptoms among computer professionals in India.

INTRODUCTION: Work-related musculoskeletal disorders are common in computer professionals. Workstyle may be one of the risk factors in the development of musculoskeletal discomfort. The objective of this retrospective study was to examine the prevalence of adverse workstyle in computer professionals from India and to evaluate if workstyle factors were predictors of pain and loss of productivity. METHODS: Office workers from various information technology (IT) companies in India responded to the short-form workstyle questionnaire and pain questionnaire. Correlation analyses were conducted to examine the associations between different variables followed by a multivariate logistic regression to understand the unique predictors of pain and loss of productivity. RESULTS: 4,500 participants responded to the workstyle and pain questionnaire. 22% of participants were reported to have a high risk of an adverse workstyle. 63% of participants reported pain symptoms. Social reactivity, lack of breaks, and deadlines/pressure subscales of workstyle questionnaire were significantly correlated with pain and loss of productivity. Regression analyses revealed that workstyle factors and duration of computer use per day were significant predictors of pain. CONCLUSION: Workstyle seems to be a mediating factor for musculoskeletal pain, discomfort, and loss of productivity. Based on the study findings, it is recommended that intervention efforts directed towards prevention of musculoskeletal disorders should focus on psychosocial work factors such adverse workstyle in addition to biomechanical risk factors.

Effects of lower extremity muscle fatigue on the outcomes of slip-induced falls.

Slip-induced fall accidents continue to be a significant cause of fatal injuries and economic losses. Identifying the risk factors causing slip-induced falls is key to developing better preventive measures to reduce fall accidents. Although epidemiological studies suggest localised muscle fatigue may be one of the risk factors for slip-induced falls, there has been no documented biomechanical study examining the relationship between fatigue and fall accidents. As such, the overall objective of the current study was to investigate the effects of localised muscle fatigue of the quadriceps on the slip initiation and slip recovery phases of slip-induced falls. Sixteen healthy, young participants were recruited to walk across a vinyl floor surface in two different sessions (fatigue and no fatigue). Kinematic and kinetic data were collected using a 3-D motion analysis system and force plates during both sessions. Results suggest that localised muscle fatigue of the quadriceps affected various kinematic and kinetic gait variables that are linked with a higher risk of slip-induced falls. Additionally, the results indicated that localised muscle fatigue of the knee extensor muscle caused a delayed response in producing an effective joint moment and base of support using the trailing limb to recover from a fall. The findings from this study indicate that localised muscle fatigue is a potential risk factor causing slip-induced falls.

Effects of quadriceps fatigue on the biomechanics of gait and slip propensity.

This study examines how lower extremity fatigue of the quadriceps alters gait variables related to slip propensity. Sixteen healthy young adults were recruited to walk across vinyl floor surfaces in states of fatigue and no fatigue. Kinematic and kinetic data were collected using a three-dimensional motion analysis system and force plates. The results indicated a significant increase in both the heel contact velocity and required coefficient of friction and a decrease in the transitional acceleration of the whole body center of mass and peak knee joint moment in the fatigue trials. Thus, suggesting that slip propensity could increase with fatigue. Additionally, there was increased knee flexion and reduced ankle dorsiflexion at the heel contact phase of the gait cycle during fatigue trials. These findings provide new insights into the biomechanical relationship between localized muscle fatigue and gait parameters associated with slip propensity. The present study concluded that localized muscle fatigue affects gait parameters and hence can be considered as a potential risk factor for slip-induced falls.