Effects of educational intervention on joint angles of the trunk and lower extremity and on muscle activities during patient-handling tasks

Abstract

Objective The objective of this study was to examine the effects of educational intervention on joint angles of the trunk and lower extremity and on muscle activities during patient-handling task. Methods Thirty-two subjects (17 males and 15 females) volunteered for the study. They were classified into three groups: intervention group 1, comprised of first grade physical therapist students; control group, which included first grade occupational therapist students; intervention group 2, which comprised third grade physical therapist students. The educational intervention during the experimental period consisted of: (1) 12 regular classes and shortterm clinical practice for the students of intervention group 1; (2) long-term clinical practice, relating to patienthandling task, for the students of intervention group 2. The following experiments were repeated before and after the educational intervention. Each subject was asked to transfer a male (55 kg) from one chair to a second chair (left to right) and then back again to the original chair (right to left). The flexion angles of the trunk, hip and knee joints were quantified by means of the dynamic threedimensional biomechanical analysis. Muscle activities (% maximum voluntary contraction, %MVC) of biceps brachii, trapezius, rectus femoris and erector spinae muscles were measured using surface electromyography (EMG). The effects of group, gender, measurement time and side on joint angles of trunk and lower extremity, %MVC of four muscle activities and transfer time were assessed.Results Although the EMG analysis could not clearly demonstrate any reduction of physical load to the low back, the flexion angles of the hip and knee joints of student subjects during the patient-handling task became larger and that of the trunk became smaller in the group given the educational intervention. Conclusion The finding of this study suggests that the posture of the study subjects changed to the squat lifting method, which is preferable for reducing the physical load to the lower back, as a result of the educational intervention.