Ab1397 Effect of Proprioceptive Exercises on Wrist Proprioception and Motor Performance: A Randomized Clinical Study

Background: In inflammatory arthritis, especially rheumatoid arthritis, the upper extremities are affected in 80-90% of cases, with the wrist being most frequently affected. In these patients, the motor function of the upper extremities is often impaired, leading to disability as the disease progresses. Chronic inflammatory joint disease and/or joint degeneration may further alter the proprioceptive sense, resulting in reduced sensorimotor control. To improve motor performance and proprioceptive control, specific exercise approaches should be incorporated into the rehabilitation program. While conscious proprioception is usually assessed by measuring joint position, the unconscious component of proprioception remains a challenge as there is no established method to assess it directly. Unconscious neuromuscular control of joints involves the activation of muscles through feed-forward control mechanisms leading to changes in electromyographic (EMG) activity. In addition to measuring motor performance, analyzing the EMG activity of the surrounding muscles of the affected joint can provide valuable insights into unconscious proprioception and also help to assess the effects of exercise on muscle recruitment. Objectives: The aim of this study was to investigate the effects of proprioceptive exercises on conscious (joint position sense) and unconscious proprioception (surface EMG signals of the forearm muscles) as well as on motor performance measures such as grip and pinch strength, reaction time and upper extremity stability in healthy individuals. Methods: A total of 41 healthy individuals (25 males, 16 females) aged 20 to 30 years (mean age 23.12 ± 2.23 years) were included in this study. Participants were randomly assigned to either group 1, which received a combination of proprioceptive exercises and traditional upper extremity exercises, or group 2, which received only traditional upper extremity exercises. Both groups performed non-dominant upper extremity exercises twice a week over a 6-week period. Motor performance outcomes included measurement of wrist position sense (flexion, extension, radial and ulnar deviation) using a validated goniometric platform, measurement of grip and pinch strength using a dynamometer, measurement of reaction time using the Nelson test, and assessment of upper extremity stability using the Y-balance test. The measurements were taken at the baseline and after the 6-week training program for both extremities. Surface electromyography (EMG) results were recorded from specific forearm and finger muscles using a Noraxon EMG device. EMG analysis was performed with an amplifier gain of x1500 mV, a bandpass filter between 10-400 Hz, a sampling rate of 5000 Hz and a common mode rejection ratio (CMRR) of 90 dB. The EMG analysis included tasks involving isotonic joint motion and grasping. EMG measurements were normalized based on the participant's maximal isometric contraction. Results: Grip strength increased and reaction time decreased in both groups. However, when comparing the two groups, group 1 was found to have significantly higher EMG muscle activity in the finger flexors (p=0.01) and extensors (p=0.007) and in the wrist flexors (p=0.02; p=0.04) during grasping compared to group 2. In addition, increased activation of wrist flexors (p=0.03) and finger flexors (p=0.02) was found during isotonic motion. Conclusion: The integration of proprioceptive exercises into the rehabilitation program has been shown to yield additional benefits in improving unconscious wrist proprioception. In patients with rheumatic diseases involving wrist, such as rheumatoid arthritis, it is possible to incorporate proprioceptive exercises into the treatment program to enhance sensorimotor control of the joints. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.