Prevalence of work-related musculoskeletal disorders among professional rickshaw drivers in Aligarh, Uttar Pradesh, India.

BACKGROUND: Professional rickshaw driving is a seemingly sedentary occupation and involves many risk factors for work-related musculoskeletal disorders (WMSD). OBJECTIVE: To assess the prevalence of work-related musculoskeletal disorders and its associated risk factors among professional rickshaw drivers. METHODS: 263 rickshaw drivers were voluntarily recruited from Aligarh, Uttar Pradesh, India. MSD symptoms in the past 12 months and last 7 days were assessed using a self-modified musculoskeletal questionnaire (Nordic Questionnaire). Chi-square tests and binary logistic regression were performed to analyze associations of MSD symptoms between study variables. RESULTS: 155 (58.9%) study participants reported MSD symptoms in past 12 months, in lower back (n = 126, 81.3%), leg (n = 122, 78.7%), neck (n = 106, 68.4%) and knee (n = 105, 67.7%); and 121 (46.1%) in last 7 days, in leg (n = 107, 88.4%), lower back (n = 102, 84.3%), neck (n = 89, 73.6%), upper back and knees (n = 87, 71.9%). Binary logistic regression showed relationship between working hours, seat and road condition, average load per ride, rickshaw ride duration, and standing driving with MSD symptoms among rickshaw drivers, especially in the lower back, leg/calf muscles, neck and knees. CONCLUSION: The results showed a high prevalence of MSD among all rickshaw drivers, with the neck, lower back, leg/calf muscles and knees being the most affected body parts. In order to avoid adverse effects on the occupational health of rickshaw drivers, ergonomic intervention training is necessary.

Investigating factors affecting musculoskeletal disorders: Predictive models for identifying caregivers at risk.

BACKGROUND: Musculoskeletal disorders (MSDs) are the most common work-related injuries identified among caregivers in the health sector as a high-risk group. OBJECTIVES: The study aimed to investigate the factors that influence musculoskeletal disorders among caregiver and to evaluate the relationship between work and non-work related factors with MSDs. METHODS: Data were collected from 104 caregivers using descriptive design and stratified cluster sampling. The survey included a demographic questionnaire and a Nordic Standardized Musculoskeletal Questionnaire. Logistic regression was performed to determine the risk factors associated with MSDs. The Odds ratio (OR) was calculated to define the influence of each risk factors. In addition, we used forward logistic regression analysis to validate the predictive model. RESULTS: In this cross-sectional survey, the results showed that 70 (67.3%) participants reported MSDs. MSD was highest at the lower back (46%), then knee (15.4%) and shoulder (11.5%). The overall success of the prediction is 90.4% (94.6 for having MSDs). The most important risk factors were manual handling (p < 0.001, odds ratio = 45.64) followed by bending (p = 0.008, odds ratio = 39.4). CONCLUSIONS: The results of this study reaffirmed the high prevalence of work-related MSD among caregiver's primarily in the lower back. The most important risk factors were manual handling, followed by bending / twisting, and handling of an excessive number of patients. Therefore, it is necessary to consider appropriate policies for managing MSDs among caregivers.

Effects of vibratory massage therapy on grip strength, endurance time and forearm muscle performance.

BACKGROUND: Vibration therapy (VT) causes an increase in motor unit activation tendency, an involuntary recruitment of earlier sedentary motor units, which increases the muscle fiber force generating capacity and muscle performance. OBJECTIVE: To evaluate the effect of vibratory massage therapy at 23 Hz and 35 Hz on grip strength, endurance, and forearm muscle performance (in terms of EMG activity). METHODS: Ten healthy and right-handed men participated voluntarily in this study. The experiment was characterized by the measurement of MVC (maximal voluntary contraction) grip strength and grip endurance time at 50%MVC, accompanied by the corresponding measurement of the EMG signals of the muscles viz., flexor digitorum superficialis (FDS); flexor carpi ulnaris (FCU); extensor carpi radialis brevis (ECRB); and extensor carpi ulnaris (ECU) in supine posture. RESULTS: MANCOVA results showed significant effects of VT frequency on endurance time (p < 0.001); but no significant effect on the grip strength (p = 0.161) and muscle performance (in terms of EMG activities of the forearm muscles). However, VT improves the MVC grip strength and grip endurance time (better at 35 Hz). The Pearson correlation was significant between: weight, palm length, palm circumference, and forearm length with MVC grip strength; and the palm length with the endurance time. In addition, the palm length, palm circumference, and forearm circumference generally serve to better predict MVC grip strength and grip endurance time. CONCLUSIONS: Vibration therapy at 35 Hz for 10 minutes on the forearms had a significant positive effect on the neuromuscular performance to enhance muscle performance of upper extermitites and can be used as the optimal range to study the effect of VT. Findings may be used to prepare guidelines for VT in rehabilitation, healthcare, sports, and medical for therapists.

Effects of vibration therapy on neuromuscular efficiency & features of the EMG signal based on endurance test.

BACKGROUND: Vibration Therapy (VT) stimulate the muscle spindles, which in turn enhances its afferent activities. OBJECTIVE: The present study was designed to investigate the effect of VT at 23 and 35 Hz on muscle performance. The EMG features (six time-domain (TD) and four frequency-domain (FD)) and a new formula for computing neuromuscular performance were used as dependent variables to evaluate the effect of VT. METHOD: The EMG recording was performed at 50% MVC during grip endurance test before and after VT. The EMG features were extracted out of raw EMG signals acquired from four forearm muscles, viz., flexor digitorum superficialis (FDS); flexor carpi ulnaris (FCU); extensor carpi radialis brevis (ECRB); and extensor carpi ulnaris (ECU) in supine position. Fatigue assessments were evaluated based on the pattern of TD and FD features. RESULTS: Statistical analysis showed a significant difference in the effect of vibration exposure frequency on IEMG (p < 0.001), MAV (p = 0.041), SSI (p = 0.032), and WL (p < 0.001) of FCU muscle. In addition, the greatest increase in neuromuscular efficiency (NME) was observed in the performance of ECRB after 35 Hz of VT and ECU muscles after 23 Hz of VT. CONCLUSIONS: The features of EMG signals could be used for fatigue analysis. However, the slope based on the median frequency regression line may be the best feature for fatigue assessment.

Effect of whole-body vibration on neuromuscular performance: A literature review.

BACKGROUND: Whole-body vibration (WBV) is a neuromuscular training method that has recently received popularity in health and fitness centers, as an additional or substitute method to conventional training and therapy, in order to improve muscle strength and power. OBJECTIVE: The purpose of this review is to critically observe the effect of WBV training on neuromuscular performance in view of its ability to enhance the muscles strength, power, and flexibility; and also to investigate the influence of the different vibration characteristics (viz., method of application of vibration, frequency, and amplitude) and exercise protocols on the effect of this training. METHOD: For this review 24 studies or articles were examined, and based on exclusion and inclusion criteria, 5 studies were finally selected; and an attempt was made to uncover the factors influencing the improvement in neuromuscular performance as a result of WBV intervention. During the review, it was considered to include and discuss as many characteristics as possible, such as, knee extension, knee flexion, counter movement jump (CMJ), squat exercise, and jumping height (JH). RESULT: Whole-body vibration, along with additional exercise training, has a potential to induce substantial improvement in neuromuscular performance. CONCLUSION: Whole-body vibration can bring about improvement in muscles strength, power, and flexibility. The main factors associated with the improvement in muscles performance are range of amplitude and frequency, type of vibration and its method of application, training intensity, exercise protocol, and the characteristics of the participants.