• PNF and Movement
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• v.16 no.1
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• pp.125-132
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• 2018

Purpose: The aim of this study was to investigate the isolated activation ratio of the quadriceps femoris muscle on different support surfaces during squat exercise. Methods: Twenty participants (10 males and 10 females) voluntarily agreed to participate in the research after receiving an explanation about the purpose and process of the study. Each participant performed squat exercises on three different support surfaces (a flat surface, a form roller, and an unstable surface). Muscle activities of the rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL) were measured by electromyography. The isolated activation ratio of the quadriceps femoris muscle was calculated using the %isolation formula. Results: For the squat exercise, the %isolation value of the VM was significantly higher on the unstable surface than on the flat surface and form roller. In contrast, the %isolation values for the RF for the squat exercise were significantly higher on the flat surface and form roller than on the unstable surface. There was no significant differences in the %isolation values of the VL on the three different surfaces. Conclusion: The findings indicate that squat exercise on different surfaces results in differential activation of the quadriceps femoris muscle, which suggests that squat exercise on a multi-directional unstable surface could increase the isolated activation ratio of the VM.

• PNF and Movement
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• v.15 no.3
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• pp.311-316
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• 2017

Purpose: Flatfeet are one of the risk factors of foot dysfunction and postural imbalance. The purpose of this study was to compare the limitation of stability (LOS) for the center of gravity (COG) between flatfeet and neutral feet on stable and unstable support surfaces. Methods: The study included 26 healthy, adult male participants: 14 with normal feet and 12 with flatfeet. The subjects were asked to incline the trunk maximumly to the left, right, anterior, and posterior directions and were asked to keep their feet on the floor with the knee extension. The subjects had 30 seconds of rest time between the tasks. The LOS (anterior, posterior, left, right) of COG was measured by Balance Trainer (BT4, Hur-labs, Tampere, Finland). An independent t- test was used to compare the LOS of COG between flatfeet and normal feet on stable and unstable support surfaces, respectively. Results: The LOS of the flatfeet group was generally decreased on stable support surfaces as compared to that of neutral feet, but it was not significantly different (p>0.05), while the LOS of the flatfeet group was significantly decreased compared to that of neutral feet on unstable support surfaces (p<0.05). Conclusion: This study suggested that the LOS of individuals with flatfeet may be decreased on unstable support surfaces and the postural balance of the flatfeet group may easily be disturbed on an unstable support surface.

• The Journal of Korean Physical Therapy
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• v.23 no.2
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• pp.7-15
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• 2011

Purpose: We investigated the relationship between the muscle activity and kinematic variables of the upper extremity during a push-up task on stable and unstable surfaces. Methods: We recruited 15 healthy subjects. Subjects completed the push-up task on stable and unstable surfaces. Surface electromyograms were recorded from the serratus anterior, upper trapezius, latissimus dorsi, infraspinatus to monitor changes in muscle activity. Markers for kinematic changes of elbow flexion, shoulder extension, shoulder retraction and scapular adduction were attached at C7, the T7 spinous process, both acromions, the scapula superior and inferior angle, the humerus lateral epicondyle, and the ulnar styloid process. Correlation coefficients between muscle activity and kinematic variables were analyzed by SPSS for Windows, version 15.0. Results: On the unstable surface, elbow flexion and shoulder extension increased with increasing muscle activity of serratus anterior, upper trapezius and infraspinatus. On the stable surface, shoulder retraction decreased with increasing muscle activity of serratus anterior and infraspinatus. Scapular adduction decreased with all types of increasing muscle activity, regardless of the support surface. Conclusion: Correlations between muscle activity and kinematic variables were observed on stable and unstable surfaces during a push-up task, while correlations between right and left variables were not clear. These finding suggest that it may be used to develop a rehabilitation program which could be effective in improving shoulder function in patients with shoulder problems.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.3
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• pp.65-72
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• 2023

PURPOSE: This study assessed the influence of bilateral coordination exercises on unstable support surfaces on leg muscle activation and balance in stroke patients. METHODS: Two groups were recruited for comparison: an experimental group of 10 individuals who performed bilateral coordination exercises on unstable surfaces and a control group of 10 individuals who performed the same exercises on stable surfaces. All participants were assigned randomly. Pre-tests were conducted to measure the leg muscle activation and balance levels of the participants prior to the experiment. The intervention was comprised of three 30-minute weekly sessions for four weeks, followed by a post-test after the four-week period. RESULTS: Significant differences were identified within the experimental group in relation to all muscles (p < .01) and balance (p < .05). Within the control group, significant differences were identified in relation to the rectus femoris muscle, biceps femoris muscle, and balance (p < .05). Significant differences between the two groups were only observed in relation to the tibialis anterior and soleus muscles (p < .05). CONCLUSION: Only the tibialis anterior and soleus muscles showed significant differences between the two groups. This effectiveness may be attributed to using an ankle strategy to maintain body balance during exercise on unstable surfaces.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.2
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• pp.89-95
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• 2019

PURPOSE: The purpose of this study was to compare task-oriented balance training on stable and unstable surfaces in terms of the fall risk, balance, and gait abilities in patients with stroke. METHODS: Twenty patients with stroke were divided randomly into a stable surface group (SSG, N=10) or unstable surface group (USG, N=10). The participants in the SSG and USG performed task-oriented balance training on stable and unstable surfaces, respectively. All participants were evaluated using the Tetrax, Berg balance scale (BBS), and 10-meter walking test (10MWT) before and after the intervention. Both groups received training 30 min per day, five times per week, for six weeks. RESULTS: The within-group changes in the fall risk, BBS, and 10MWT were significantly different in both USG and SSG (p<.05). USG showed significantly more improvement in the BBS and 10MWT compared to SSG (p<.05). CONCLUSION: Task-oriented balance training on an unstable surface is more beneficial in improving the balance and gait abilities of stroke patients.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.2
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• pp.33-40
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• 2016

PURPOSE: The purpose of this study was to determine the impact of stable and unstable surfaces on abdominal muscle thickness and changes in trunk muscle thickness in accordance with breathing methods during bridging exercises. METHODS: Bridging exercise on a stable surface, bridging exercise on an unstable surface, bridging exercise using a drawing-in maneuver on a stable surface, bridging exercise using a drawing-in maneuver on an unstable surface, bridging exercise using bracing on a stable surface, bridging exercise using bracing on an unstable surface. In sequence, the muscles' thickness was measured three times before and after each exercise, and the measured value was averaged. RESULTS: There were significant differences in internal oblique and transversus abdominis muscles' thickness in the drawing-in maneuver in both stable and unstable surface (p<0.05). There were no significant differences in external oblique muscle's thickness in the bridging exercise in both stable and unstable surface. The type of surface did not have a significant influence on the abdominal muscles' thickness. CONCLUSION: As a result of the study, the drawing-in maneuver had a greater effect than bridging or bracing maneuver on muscle thickness. We suggest that drawing-in maneuver will be more effective in a person with a weak abdominal muscle.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.20 no.2
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• pp.1-7
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• 2014

Purpose: The purpose of this study was to compare the effects of the balance training on the stable and unstable supporting surfaces for the subjects with functional ankle instability. Methods: Twenty-nine subjects with functional ankle instability were randomly assigned to the stable group (n=14) and the unstable group (n=15). Balance training was conducted twenty minutes a day on the stable surface for the stable group and on the airostep for the unstable group three times a week for four weeks. Balance training program was consisted of ten steps by eye opened or closed and two or one leg standing. X-speed for transverse balance and Y-speed for longitudinal balance were measured with eye opened and closed in affected leg standing position. Results: There were significant improvements of balance ability in eye opened (p<.01) and eye closed standing (p<.01) in stable group. Unstable group also showed significant improvements of balance ability in eye opened (p<.01) and eye closed standing (p<.01). There were no statistical differences in the magnitude of improvement between the groups (p<.05). Conclusions: Based on such results, it can be said that balance training on the stable surface is effective as much as training on the unstable surface for the subjects with functional ankle instability.

• Journal of Korean Physical Therapy Science
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• v.25 no.3
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• pp.53-60
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• 2018

Purpose : The purpose of this study is to examine the Effect of Lunge Exercise on the Balance of Stable and Unstable Supporting surface. Method : The experimenter was a healthy twenties male and female. The period was two weeks, divided into a stable group and a unstable group. Setting the holding time 4 sec 3 sets of 10 times using the Stable and Unstable Supporting Surfaces. The break time was set at one minute for each set. Balance cushions were used for unstable supporting surfaces. Results : After Lunge Exercise, Both groups had an impact on improving their ability to balance. Conclusion : There has not been much change in the ability to balance the stable and Unstable Supporting Surfaces. However, considering surface conditions, the pre and post exercise comparisons had an effect on improving the ability to balance.

• The Journal of Korean Physical Therapy
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• v.34 no.5
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• pp.242-247
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• 2022

Purpose: This study investigates the effect of 60° semi-squat exercises according to three different types of support surfaces. The effects were examined on joint position sense and balancing ability using stable and unstable surfaces in patients afflicted with post-stroke hemiplegia. Methods: Subjects were instructed to perform three sets of 60° semi-squat exercises according to the characteristics of the support surface conditions. The three ground states were bilateral stable surface (BSS), nonaffected side unstable surface (NUS), and bilateral unstable surface (BUS). The joint position sense, characteristics of body sway, and dynamic balance were analyzed according to floor conditions before and after the experiment. A balance-pad (50 cm W×41 cm L×6 cm H; Alcan Airex AG, Sins, Switzerland) was used for the unstable floor. Results: The 60° semi-squat exercises applied to hemiplegic patients showed the highest statistical significance in joint position sense in the NUS group, and Timed Up and Go test (TUG) in the BUS group (p<0.05). Conclusion: Functional training using an unstable surface can be applied as a meaningful intervention method for improving the balance and joint position sense of stroke patients.

• The Journal of Korean Physical Therapy
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• v.26 no.2
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• pp.110-116
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• 2014

Purpose: The purpose of study was to investigate the effects of combination patterns exercise of Proprioceptive Neuromuscular Facilitation (PNF) on unstable surfaces on pain, functional disability, and fear avoidance belief in patients with chronic low back pain. Methods: Twenty four patients were assigned to either the experimental group (n=12) or the control group (n=12). Patients in the experimental group performed combination patterns exercise of PNF on unstable surfaces. Patients in the control group performed combination patterns exercise of PNF on stable surfaces. Both exercises were performed for five days per week, for a period of six weeks. Pain was measured by the Visual Analogue Scale (VAS) and University of Alabama at Birmingham (UAB). Functional disability was measured using the Oswestry Disability Index (ODI) and Roland Morris Disability Questionnaire (RMDQ). Fear avoidance belief was measured using the Fear Avoidance Beliefs Questionnaire (FABQ). A paired t-test was used for determination of differences before and after treatment, and an independent t-test was used for determination of differences between treatment groups. Results: In within group comparison, the experimental group showed statistically significant difference for all variables (p<0.05). In comparison between two groups, the experimental group showed relatively greater significant difference for all variables (p<0.05). Conclusion: Based on such results, it can be said that combination patterns exercise of PNF on unstable surfaces has an effect on pain, functional disability, and fear avoidance belief in patients with chronic low back pain.