Background: Since chronic ankle instability (CAI) can adversely affect postural control, core stability exercises have been investigated to improve postural control. However, only a few studies have focused on kinetic chain exercises. Objectives: To investigate the effects of open kinetic chain (OKC) and closed kinetic chain (CKC) core stability exercises on static and dynamic balance abilities and vertical jump height in CAI patients. Design: Randomized controlled trial. Methods: The 18 participants enrolled in this study were randomly divided into the OKC group (n=9) and CKC group (n=9). Static and dynamic balance abilities and vertical jump height were measured before and after the intervention. The intervention program comprising OKC or CKC core stability exercises depending on the groups was conducted for 30 min twice a week for 6 weeks in 12 sessions. Results: In the OKC group, static measured with the eyes open or closed and dynamic balance abilities were significantly improved after the intervention (P<.05). In the CKC group, dynamic balance ability was significantly increased (P<.05). A significant difference was observed in static balance ability measured with the eyes open between the two groups (P<.05). Vertical jump height was significantly increased after the intervention in both groups (P<.05). Conclusion: OKC and CKC core stability exercises improve static and dynamic balance abilities and vertical jump height in CAI patients. Specifically, the OKC core stability exercise was more effective in enhancing static balance ability than the CKC core stability exercise.

Background: The CKCUES test evaluates the functional performance of the shoulder joint. The CKCUES test scores CKC exercises of the upper limbs to examine shoulder stability. Although the CKCUES test provides quantitative data on functional ability and performance, no study has determined the relationship between CKCUES scores and SA and TB muscle strength. Objects: The objective of this study is to determine the relationship between the CKCUES test scores and the strength of the SA and TB muscles in the CKCUES and unilateral CKCUES tests. Methods: Sixty-six healthy male volunteers participated in the study. A Smart KEMA strength sensor measured SA and TB muscle strength. Two parallel lines on the floor indicated the initial hand placement to start CKCUES tests. For 15 seconds, the subject raises one hand and reaches over to touch the supporting hand, then returns to the starting position. Results: The correlation between the CKCUES test scores and the strength of the SA was strong (r = 0.650, p < 0.001), and the TB was moderate (r = 0.438, p < 0.001). The correlation between the unilateral CKCUES test and the strength of the SA of the supporting side was strong (r = 0.605, p < 0.001), and swing side was strong (r = 0.681, p < 0.001). The correlation between the unilateral CKCUES test and the strength of the TB of the supporting side was moderate (r = 0.409, p < 0.001), and swing side was moderate (r = 0.482, p < 0.001). Conclusion: Our study showed that the CKCUES test had a strong association with isometric strength of SA and moderate association with that of TB. These findings suggest that the CKCUES test can evaluate the function of the SA. Moreover, the unilateral CKCUES test can evaluate unilateral shoulder function.

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.

Background: Several studies have discussed diverse exercise methods considered to be useful for the selective contraction of the vastus medialis oblique (VMO) muscle for the treatment of patellofemoral pain syndrome. Some studies have reported that exercise methods, including hip adduction, in closed kinetic chain exercises are more effective in terms of the muscle activation of the VMO and the timing of the muscle’s initial contraction. We focused on isometric contraction during a closed kinetic chain exercise with hip adduction. Objects: The purpose of this study was to examine muscle activation in the VMO and the vastus lateralis (VL) and the onset time difference between their initial contractions via closed kinetic chain isometric quadriceps femoris exercises including hip adduction. Methods: In total, 36 healthy subjects adopted two hip positions during isometric contraction of the quadriceps femoris in a closed kinetic chain exercise (hip neutral and hip adduction position). Statistical analyses were conducted using a paired t-test (α=.05). Results: Isometric contraction of the quadriceps femoris in a closed kinetic chain exercise caused a greater increase in VMO muscle activity in the hip adduction position [52.68±22.21 percentage of maximal voluntary isometric contraction (%MVIC)]than the hip neutral position (43.43±19.85 %MVIC). The onset time difference (VL-VMO) decreased more in the hip adduction position (-82.14±34.2 ㎳) than the hip neutral position (73.94±2.94 ㎳). Conclusion: We recommend this exercise as a clinically useful therapeutic method for patients with patellofemoral pain syndrome due to weakening of the VMO muscle and lateral inclination of the patella.

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.