The comparison of the effects of pnf and static stretching applied to the elbow flexors on muscle architecture and viscoelastic properties in individuals with chronic stroke

Introduction: Two-thirds of stroke patients have upper extremity motor function loss. Restoring structural changes by reducing increased muscle tone in the upper extremity is an important goal of upper extremity rehabilitation. Aim: This study aims to investigate the effects of Proprioceptive Neuromuscular Facilitation stretching (PNFs) and sustained static stretching (SSSs) methods to be applied to the elbow flexor muscles (Biceps Brachii, Brachioradialis and Brachialis) in addition to upper extremity neurodevelopmental therapy (NDT) on the muscle architecture and viscoelastic properties, spasticity level, upper extremity function and motor performance, elbow passive joint range of motion (ROM), proprioception and posture among chronic stroke patients with elbow flexor spasticity. Methods: The 34 patients diagnosed with stroke and in the chronic phase were included in the study and were randomly divided into two groups. In addition to NDT, PNFs (PNFs group) and SSSg (SSSg group) exercises were applied to the cases by a specialist physiotherapist in the clinic, for 4 weeks and 5 days a week, a total of 20 sessions. Ultrasonographic imaging, myotonometric measurements, Modified Ashworth Scale, Fugl Meyer Evaluation Scale, Square-Drawing Test, goniometric measurement, Joint Position Reproduction Test and a phone application called PhysioMaster were used for pre- and post-treatment evaluations. SPSS program was used to analyze the data and p<0.05 was considered statistically significant. Results: The study was carried out by analyzing the data of 33 cases. At the end of 4 weeks, echogenicity of all elbow flexor muscles, Brachialis muscle pennation angle, Biceps Brachii muscle elasticity, elbow flexor spasticity, shoulder alignment/level (p<0.05) and motor function and performance, passive ROM, proprioception, elbow posture parameters (p≤0.001) was observed to improve significantly. In terms of GroupxTime interaction, there was a significant difference in favor of the USSg group only for the pennation angle (p=0.014; Pη2=0.181) and length (p=0.038; Pη2=0.131) measured at maximum elbow extension, while there was no significant difference in favor of either group in any of the other parameters (p> 0.05). Conclusion: PNFs applied in addition to NDT seems to be an alternative intervention method for patients who cannot tolerate USSg, as it can produce effects similar to USSg in improving muscle echogenicity, reducing spasticity, improving motor function and performance, passive ROM, proprioception and elbow posture.