Repetitive low-intensïty work constitutes an important risk factor for Chronic Wark Related Neuromuscular Disorders (CWRND)· Derangemcnt of motor control, provoked by loaded or fati ued muscles, has been suggested as one of the underlying mechanisms behind these disorders. Faàgue-induced reduetion of proprioceptive acuity may be one of the factors accounting for the deranged motor eontrol. In contrast to high-intensity work, little ïs known about the effect of repetitive low-intensity work on proprioceptive acuity. Muscle stretching has becn proposed as a rocedure that can prevcnt, alleviate and/or treat CWRND· Before the importance of stretching can be adequately assessed for this purpose, a better understanding of the effects of stretching and the pathophysiological mechanisms behind thc work-related disorders are needed. The aims of the thesis were (i) to investigate the impact of repetitive low-intensity work exposure on proprioception and (ü) to examine effects of muscle stretching (especially sensory effects and effects on muscle nociception) and to relate its application to the prevention, alleviation and/or treatment of CWRND A simulated occupational setting was used to test the effects of low-intensity repetitive work on the shoulder proprioception in healthy subjècts. The effect of working time on the retention of subjective fatigue and their relation to changes in proprioception, and the immediate effect of stretching on shoulder proprioception were investìgated. A new method to test the stretchability of the rectus femoris muscle was investigated for reliability and validity and used to assess the effects of a 2-week stretching regimen on range of motion and an subjecàve stretch sensation. Finally, the interactions between innocuous musclc stretch and naciceptive chemical stimulaàon on discharge behavior of nociceptive dorsal horn neurons in the feline spinal cord were explored. The main findings wcre as follows: 1) The repctiàve low-intensity work to fatigue diminished the shoulder proprioceptian; the working time as well as the retention of subjective fatigue were partly related to the extent of changed praprioception: 2) There was no effect of acute muscle stretching on the proprioccpàon. 3) The ncw method for tesàng musele stretchability proved valid and reliable. A two-week stretching regimen inereased the tolerance to stretch torque, but the range of moàon remained unchanged. 4) Half of the nociceptive dorsal horn neurons that responded to close arterial injections of bradykinin were modulated by muscle stretching applied directly aftér thc injections. h thcsis of an involvement of sensory Altogether, the results give credence to the hypo information distonion due to repeàtive low.intensity work exposure in the development of CWRND· Increased toleranee to stretch torque may be an imponant mechanism i explaining improvements followin stretch treatment. The spinal interactions between innocuaus stretch and nociceptive muscle af erent inputs indicate a possible mrchanism involved in stretching-induced pain alleviaàon.