Abstract Introduction: The human body can adopt various types of postures. Typical examples of deviations from neutral posture around the low back are forward and backward bending, side bending and rotation [1]. Body part discomfort (BPD) scale has become a standard discomfort assessment tool. While performing a task, the worker indicates the body areas in which discomfort is felt as a result of the task, and assigns a severity to the discomfort of each body part [2,19,40,45]. Aims and Objectives: The main aim and objective of this study was to observe the effects of deviation from neutral position on the perceived joint discomfort rating in neck and back in sitting and standing position. Methods: A total of forty subjects were selected based upon the inclusion and exclusion criteria. The 20 out of the 40 subjects were asked to maintain static joint posture for the neck. The postures included were flexion, extension, right and left side flexion and right and left rotation. The subjects were asked to maintain these posture in the sitting position. The remaining 20 subjects were asked to maintain the same static joint posture in sitting position for the neck but in reverse order. The first 20 subjects were then asked to maintain static joint posture for the low back in sitting position. The postures included were flexion, right and left side flexion and right and left rotation. The remaining 20 subjects were then asked to maintain the same static joint posture for the low back in sitting position but in the reverse order. Discussion: These findings suggest as stated earlier that perceived joint discomfort has a direct correlation with the torque produced in the muscle around the joint and higher the torque more will be the discomfort. H. Monod reported that exhaustion of a muscle engaged in static activity is mainly due to ischaemia created inside the muscle by the contracting force [35]. Wilke et al. (1999) measured spinal disk pressure for various activities and found that there was a lower spinal load in sitting when compared to standing [25,70,72]. In our study flexion of the back produce second highest discomfort rating. This is born out on the basis that trunk flexion increases the load on the spine by increasing the forward bending moment on the spine [30]. Conclusion: Based on the finding of this study we can conclude that lateral bending of the cervical appears to cause more discomfort than the flexion, extension and rotation when performed in the standing position as compared to sitting. Similarly, lateral bending of the lumbar spine appears to cause more discomfort than any other static joint posture, when performed in standing position as compared to sitting. Limitation of the Study: 1. Small sample size. 2. Perceived joint discomfort scale is a subjective scale and its accuracy depends on the level of understanding of subject. 3. No blinding was done. 4. Lumbar extension in sitting position was not included in the study. 5. Lumbar rotation ROM was not measured.
Keywords: Joint Discomfort Scale; Stop Watch; Perceived Joint Discomfort; Cervical; Lumbar; Static Posture; Sitting; Standing