Elbow-Height Handle and Staggered Stance Exhibited Greatest Force in Pushing and Pulling: A Study among Malaysian Adults

@#Introduction: Pushing and pulling activities are common in daily life and industrial workplaces. These activities are potentially contributing to muscle fatigue in the back and shoulder if not managed ergonomically. Therefore, this study aimed to quantify the maximum strength of Malaysian adults in horizontal symmetrical two-handed pushing and pulling with different handle heights and stances. Methods: Forty-seven participants of 24 males and 23 females were recruited in pushing and pulling experiments. The participants were assistant engineers and postgraduate students of a technical university. The dependent variable was the magnitude of push/ pull force. The independent variables consisted of action, handle height and stances. The experimental design was set for 2 actions, 3 handle heights and 2 stances, yielding 12 variables combinations. Results: Key findings of this study revealed that combination of pull action, handle height at elbow level and staggered stance exhibited greatest force. On the contrary, combination of push action, handle height at knuckle level and parallel stance resulted in lowest force. In pushing test, both male and female participants obtained greatest force of 233.3 N and 121.7 N, respectively, when the handle height was at elbow level and staggered stance. Similarly, in pulling test, males and females obtained highest force of 242.9 N and 152.4 N, respectively. Conclusion: This study concluded that handle height at elbow level and staggered stance exhibited greatest force in pushing and pulling activities. This study provides information to individuals who involved in pushing and pulling tasks with least force exertion to minimize muscle fatigue in the back and shoulder. Future studies should consider the following recommendations: 1) Participants of study should involve manufacturing industry workers. 2) To study the effect of pushing and pulling tasks on muscle activity.

Advance in Muscle Strength Assessment for Critical Patients (review) / 中国康复理论与实践

The mechanism of muscle damage in critically ill patients mainly includes microcirculation disorder, changes in cells and metabolism, inflammation, increased myoprotein breakdown in muscular atrophy, and inactivation of ion channels. Manual muscle testing is the most commonly used muscle strength measurement for critically ill patients, which is simple and economic, but subjective, being not accurate and sensitive in evaluating muscle weakness of patients and distal limb function. Neuroelectrophysiological testing is safe, non-invasive, simple and objective, but it requires specialized equipment and trained qualified professionals, high medical costs, time and effort consumption, and lack of specificity. Dynamometer is a simple, objective, convenient and inexpensive assessment method, which has a good reliability and validity in application in the critically ill patients, but it is not widespread in China.