Quantitative Models for Prediction of Cumulative Trauma Disorders Applied to the Maquiladora Industry

Grip force makes wrist joint position sense worse

Background

The purpose of this study was to investigate how grip force affects wrist joint position sense.

Methods

Twenty-two healthy participants (11 men and 11 women) underwent an ipsilateral wrist joint reposition test at 2 distinct grip forces [0 and 15% of maximal voluntary isometric contraction (MVIC)] and 6 different wrist positions (pronation 24°, supination 24°, radial deviation 16°, ulnar deviation 16°, extension 32°, and flexion 32°).

Results

The findings demonstrated significantly elevated absolute error values at 15% MVIC (3.8 ± 0.3°) than at 0% MVIC grip force [3.1 ± 0.2°, t(20) = 2.303, P = 0.032].

Conclusion

These findings demonstrated that there was significantly worse proprioceptive accuracy at 15% MVIC than at 0% MVIC grip force. These results may contribute to a better comprehension of the mechanisms underlying wrist joint injuries, the development of preventative measures to lower the risk of injuries, and the best possible design of engineering or rehabilitation devices.

Temperature Asymmetry Analysis between Left and Right Wrist with Sensory and Infrared Thermography

This article reports a thermal analysis of the wrists to analyze the behavior and recovery of skin temperature after 20 min when performing a highly repetitive movement, and two thermography methods (sensory and infrared) and research groups were compared. The tests were carried out with 44 participants who performed a repetitive task for 10 min and integrated into two groups, of which 22 were trained workers from a maquiladora company and were analyzed with sensory thermography, and the other 22 were in the laboratory with infrared thermography with undergraduate students. The study area is the left and right hand, specifically the wrists. The proposed hypothesis is that people with some musculoskeletal problems have a decrease in temperature when starting repetitive tasks and thermal asymmetries, which measurements were recorded at 0, 10, 15, and 20 min after the task was finished. Findings indicate that the temperatures in both wrists behave similarly. The workers reached higher temperatures, and the centigrade degrees of asymmetry difference were also higher. The variable with influence on the temperature was fractured in the arm. After thermally analyzing the temperature behavior between the wrists of both hands, it is concluded that there is an increase in temperature after finishing a repetitive task, and it does not stabilize after 20 min. Both thermography methods observed that the asymmetries are greater than 0.5 °C, detecting the possible pathology of carpal tunnel syndrome.