Background: After stroke, in order to improve gait function, it is necessary to increase the muscle strength and to enhance the propriocetive function of the lower extremity. Objects: This study aimed to compare the effects of open kinetic chain (OKC) versus closed kinetic chain (CKC) isokinetic exercise of the hemiparetic knee using the isokinetic equipment on lower extremity sensorimotor function and gait ability in patients with chronic stroke. Methods: Thirty participants with chronic hemiplegia (> 6 months post-stroke) were randomly divided into 2 equal groups: CKC group and OKC group. Patients from both groups attended conventional physiotherapy sessions 3 times a week for 6 weeks. Additionally, subjects from the CKC group performed isokinetic exercise using the CKC attachment, while those from the OKC group performed isokinetic exercise using the OKC attachment. The isokinetic knee and ankle muscles strength, position sense of the knee joint, and spatiotemporal gait parameters were measured before and after interventions. Results: The knee muscles peak torque/body weight (PT/BW) and hamstring/quadriceps (H/Q) ratio significantly increased in both groups (p<.01). In particular, ankle plantarflexors PT/BW, position sense of the knee, gait velocity, and spatial gait symmetry significantly improved in the CKC group (p<.01, p<.05, p<.01, and p<.01, respectively). Conclusion: CKC isokinetic exercise can be an effective therapeutic intervention for the improvement of sensorimotor function of the lower extremity and gait functions, such as gait velocity and symmetry. CKC position in isokinetic strength training is effective to improve functional ability in patients with chronic stroke.

Background: Methods for exercising serratus anterior (SA) and upper trapezius (UT) muscles are important for the recovery of patients with various shoulder disorders, yet the efficacy of closed or open kinetic chain exercises have not yet been evaluated. Objects: The purpose of this study was to compare the activation of the SA and UT muscles during scapular protraction considering both closed and open kinetic chain exercises. Methods: Thirty subjects were randomly divided into experimental groups (closed kinetic chain exercise) and control groups (open kinetic chain exercise) in which scapular protraction was performed at 90° or 125° shoulder flexion. Electromyographic activity data were collected from the SA and UT muscles per position and exercise method. Results: Separate mixed 2-way analysis of variance showed significant differences in the activation of the SA (F1,28=6.447, p=.017) and the UT (F1,28=35.450, p=.001) muscles between the groups at 90° and 125° shoulder flexion. Also, the SA/UT ratio measures at 90° and 125° shoulder flexion significantly differed between the groups (F1,28=15.457, p=.001). That is, the closed chain exercise was more effective than open chain exercise for strengthening the SA muscle and controlling the UT muscle, 125° of shoulder joint was more effective than 90°. Conclusion: The findings suggest that scapular protraction with shoulder 125° flexion at the closed kinetic chain exercise may be more effective in increasing SA muscle activation and decreasing UT muscle activation as well as increasing the SA/UT ratio than open kinetic chain exercise.

The purpose of this study is to investigate the effects of closed and open kinetic chain exercise for increasing knee joint function on the knee position sense in the normal adults. Thirty normal adults(male 15, female 15; mean age: 22.13±2.58 years) were participated in this study into two groups, each with 15 people. The group I was trained that closed kinetic chain exercise on the knee joint and the group II was trained that open kinetic chain exercise on the knee joint. Exercise programs performed for 4 weeks, 3 times a week were using Shuttle 2000-1 closed kinetic chain exercise and Knee Extensor open kinetic chain exercise(HUR, Filand). The results of this study were as follows: 1) There were statistically significant decreasing of measuring error degree in 0-20。were found between before and after training in closed kinetic chain exercise(p<.05). 2) There were statistically significant decreasing of measuring error degree in 21-40。were found between before and after training in closed kinetic chain exercise(p<.05). 3) There were statistically significant decreasing of measuring error degree in 41-60。were found between before and after training in closed kinetic chain exercise(p<.05). 4) There were statistically significant decreasing of measuring error degree in 0- 20。were found between before and after training in open kinetic chain exercise(p<.05). 5) There were statistically significant decreasing of measuring error degree in 21-40。were found between before and after training in open kinetic chain exercise(p<.05). 6) There were statistically significant decreasing of measuring error degree in 41- 60。were found between before and after training in open kinetic chain exercise(p<.05). In conclusion, these results suggest that closed and open kinetic chain exercise has increased in the knee joint proprioception between before and after training. Especially, closed kinetic chain exercise could be more useful intervention than open kinetic chain exercise for increasing proprioceptive sense.