• Journal of Biomedical Engineering Research
• /
• v.29 no.6
• /
• pp.484-492
• /
• 2008

Sit to stand(STS) movement is one of the most common activity in daily life. In addition, Korean traditionally stand up from various sitting heights in one's daily life compared to other foreigners. As Korea enter rapidly to the aging society, needs of the elderly's independent life are increasing. Therefore the importance of research about the analysis of elderly's activity in daily life is rapidly increasing. In this study, we analyzed joint movements and changes of muscle length during STS(sit-to-stand) at various sitting heights(table seat, bath seat, bottom) in the Korean elderly's daily life by using the motion analysis and musculoskeletal modeling. Ten Korean elderly and young were participated in this experiment. Three heights of sitting posture which could represent typical sitting in Korean daily life were chosen as table seat(42cm), bath seat(21cm) and bottom(0cm). As the results, the elderly showed both smaller knee/hip flexion and larger trunk flexion relatively in comparison to the young during table seat STS. The elderly also showed larger dorsiflexion and smaller ROM of knee, hip, trunk compared to the young during bath seat STS. Additionally, the elderly showed larger plantarflexion, hip flexion, smaller knee flexion and trunk flexion during the first half of bottom STS and larger knee flexion, hip flexion and trunk flexion during the second half of bottom STS. In addition, we could know contraction and relaxation characters of major muscles in lower limb during various STS through the analysis of changes in muscle length by musculoskeltal modeling.

• The Journal of Korean Academy of Sensory Integration
• /
• v.17 no.1
• /
• pp.9-18
• /
• 2019

Objective : This study investigated the effect of intensive weight shift training (IWST) on the ability to balance in a sitting posture of children with spastic cerebral palsy (SCP). Methods : One child with spastic diplegia participated in this study for a total of 8 weeks using the ABA experimental design. For the pre-intervention period (A1), general physical therapy (GPT) for children with SCP was performed. The intervention period (B1 and B2), GPT and IWST were conducted for children with SCP, and GPT was conducted again for the post-intervention period (A'1 and A'2). Trunk control capacity was measured using the Korean Trunk Control Measurement Scale (TCMS-K) and Biorescue (RM Ingenierie, France). Results : All TCMS-K variables increased from A1 to B2, and decreased from B2 to A'2. The total area with limit of stability (LOS) increased from A1 to B2, and decreased from B2 to A'2. The ratio of the left/right (Lt/Rt) and anterior/posterior (Ant/Post) LOS area was closer to 1, meaning symmetry, in B2 than in A1. The ratio of the Lt/Rt LOS area decreased further from 1 in A'2 than in B2. The ratio of the Ant/Post LOS area was closer to 1 in A'2 than in B2. Conclusion : IWST had a positive effect on the improvement of balance in the sitting posture of a child with SCP. The results suggest that IWST might help to improve the balance abilities of children with SCP for independent sitting, postural control, and activities of daily living.

• Physical Therapy Korea
• /
• v.23 no.1
• /
• pp.87-93
• /
• 2016

Background: Posture balance control is the ability to maintain the body's center of gravity in the minimal postural sway state on a supportive surface. This ability is obtained through a complicated process of sensing the movements of the human body through sensory organs and then integrating the information into the central nervous system and reacting to the musculoskeletal system and the support action of the musculoskeletal system. Motor function, including coordination, motor, and vision, vestibular sense, and sensory function, including proprioception, should act in an integrated way. However, more than half of stroke patients have motor, sensory, cognitive, and emotional disorders for a long time. Motor and sensory disorders cause the greatest difficulty in postural control among stroke patients. Objects: The purpose of this study is to determine the effect of visual and somatosensory information on postural sway in stroke patients and carrying out a kinematic analysis using a tri-axial accelerometer and a quantitative assessment. Methods: Thirty-four subjects posed four stance condition was accepted various sensory information for counterbalance. This experiment referred to the computerized dynamic posturography assessments and was redesigned four condition blocking visual and somatosensory information. To measure the postural sway of the subjects' trunk, a wireless tri-axial accelerometer was used by signal vector magnitude value. Ony-way measure analysis of variance was performed among four condition. Results: There were significant differences when somatosensory information input blocked (p<.05). Conclusion: The sensory significantly affecting the balance ability of stroke patients is somatosensory, and the amount of actual movement of the trunk could be objectively compared and analyzed through quantitative figures using a tri-axial accelerometer for balance ability.

• Journal of Korean Physical Therapy Science
• /
• v.9 no.2
• /
• pp.27-36
• /
• 2002

The purpose of this study was to examine the effects of graded low back exercise program with patient education about low back pain care on abdominal strength, endurance and flexibility of waist of chronic low back pain patents. For this study 13 patients aged 40 to 60 were selected as subjects, who suffered from low back pain and got diagnosed by physician. The exercise program and the education were executed for total 6 weeks, posture education were executed with physical exercises over first 1 to 4 weeks period and over 5 to 6 weeks the exercises were executed. The effect of the exercises and the education were evaluated through weights, WHR, fat(%), flexibility by sit-and-reach and trunk extension test, strength by sit-up test and back sit-up test. Weights were, decreased after physical exercise and education, but there was no statistical significance. Wasit hip ratio(WHR) and fat(%) were decreased after physical exercise and education, but there were no statistical significances. Sit-and-reach was significantly increased from $13.68{\pm}5.59cm$ to $19.45{\pm}3.81cm$ after education and physical exercise(P<0.05). Trunk extension was significantly increased from $30.31{\pm}11.34cm$ to $40.88{\pm}6.16cm$ after education and physical exercise(P<0.05). Sit-up and Back sit-up were increased after physical exercise and education, but there were no statistical significances. These results suggest that graded low back exercise program with patient education about low back pain care increase the abdominal strength, endurance and the flexibility of waist in low back pain patients.

• The Journal of Korean Physical Therapy
• /
• v.27 no.3
• /
• pp.159-163
• /
• 2015

Purpose: This study aimed to determine the interaction among the neck, trunk, and lower extremities on the non-paretic side in head rotation along with non-paretic-side weight shifting of stroke patients. To compare stroke patients' ability to control posture through muscle activity variation related to pertubation during head rotation along with the non-paretic limb. Methods: We tested 15 hemiplegic patients and 15 normal individuals. Each group's muscle activity was measured by electromyography in neutral head position and head rotation position. We compared each group's resu lt based on measured values in patients' non-paretic neck muscles, trunk muscles, and lower limbs muscles activation. Results: The study showed that muscle activity increased in the sternocleidomastoid muscle (102.26%, 53.00%), splenius capitis muscle (97.93%, 54.93%), erector spinae muscle (241.00%, 127.60%), external oblique abdominal muscle (256.66%, 152.00%), and internal oblique abdominal muscle (252.80%, 152.6%), peroneus longus muscle (117.53%, 137.13%) and gastrocnemius muscle (119.06%, 137.20%), while the results for the sternocleidomastoid muscle, splenius capitis muscle, erector spinae muscle, external oblique abdominal muscle, internal oblique abdominal muscle, peroneus longus muscle, and gastrocnemius muscle showed a statistically significant difference (p<0.05). Conclusion: It is hard for stroke patients to engage in normal movement control under suggested conditions because of the insufficient movement against gravity on the stroke patient's non-paretic side and impaired cooperative patterns. To solve these problems, patients need their bodies to improve through effective movement, resulting in advanced control of their effective and functional activity.

• Korean Journal of Applied Biomechanics
• /
• v.14 no.1
• /
• pp.27-40
• /
• 2004

The purpose of this study was to provide basic data for improving athletic performances by analyzing the kinematic variables of the Double Backward Somersault on the Parallel Bars through the 3D motion analysis. The subjects in this study were 5 male gymnasts who were ranked as national athletes. The results are as follows. 1. A total time(Mean Time) of performance showed $2.72{\pm}0.82\;sec$. and flight time to landing after releasing was 0.87sec.(mean). In order to perform better stable flying movement, the flight time should be increased. 2. In the change of velocity of the center of mass, when the increasing ascension velocity of the upper point was high, the position in the top point was high on releasing. 3. In the position variable of the center of mass, the mean of upper-bottom position in horizontal posture was $242.1{\pm}6.5cm$, $232.8{\pm}6.4cm$ in releasing, and $265.0{\pm}5.6cm$ in the highest point. This result is explained that the position of center of mass can be raised by using elastic power when wrist raised the bar in the releasing movement. 4. The angle of shoulder joint was $271.1{\pm}14.0$. Such a big angle influences a negative effect on the releasing velocity, because trunk is not a position in the enough vertical direction. 5. The ankle of hip joint in hand-standing was $191.1{\pm}5.9$, $118.8{\pm}5.3$ in releasing, and $122.3{\pm}5.3$ in taking on. Therefore, the result suggests that trunk should be straightly raised in taking on.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.4
• /
• pp.181-189
• /
• 2005

To know the proper impact posture and changes for the various clubs, changes of impact variables according to the change of golf club length was investigated. Swing motions of three male low handicappers including a professional were taken using two high-speed video cameras. Four clubs iron 7, iron 5, iron 3 and driver (wood 1) were selected for this experiment. Three dimensional motion analysis techniques were used to get the kinematical variables. Mathcad and Kwon3D motion analysis program were used to analyze the position, distance and angle data in three dimensions. Major findings of this study were as follows. 1. Lateral position of the head remained more right side of the target up to 3.5cm compared to the setup as the length of the club increased. 2. Left shoulder raised up to 5cm and right shoulder lowered up to 2.5cm compared to setup. The shoulder line opened slightly (maximum 11 degrees) to the target line. 3. Forward lean angle of the trunk decreased up to 4 degrees (more erected) compared to setup. 4. Side lean angle of the trunk increased compared to setup and increased up to 16 degrees as the club length increased. 5. The pelvis moved to the target line direction horizontally and opened up to 31 degrees. Right hip moves laterally to the grip position at the setup. 6. Flexion of the left leg maintained almost constantly but the right leg flexed up to 11 degrees compared to setup. 7. Left arm is straightened but the right arm flexed about 20degrees compared to straight. 8. Center of the shoulders were in front of the knees and toes of the feet. 9. Hands moved to the left (8.7cm), forward (5.7cm) and upward (11.6cm) compared to the setup. This is because of the rotation of pelvis and shoulders. 10. Shaft angle to the ground was smaller than the lie angle of the clubs but it increased close to the lie of the clubs at impact.

• Journal of the Ergonomics Society of Korea
• /
• v.32 no.3
• /
• pp.229-236
• /
• 2013

Objective: The purpose of this study was to analyze the effects of wearing spandex underwear on the muscle activity and heart rate during flexion and extension of trunk and knee joint. Background: Back pain continues to be the leading overall cause of physical illness and lowering productivity in workplace. Recently, the utility of assistive garment or back belt have been discussed to lessen the back pain as well as to preserve the right posture. Method: Ten males and ten females participated in the experiment. Gender, wearing spandex underwear and postures were used for independent variables, and muscle activity, the level of asymmetry of muscle activity and variation of heart rate were used as dependent variables. Muscle activity and heart rate were measured during flexion and extension of trunk and knee joint. Results: When wearing spandex underwear, the muscle activity was relatively low compared to the condition not wearing the spandex underwear. The symmetry of muscle activity and the variation of heart rate were statistically significant at the 0.05 significance level. In particular, it was found that the symmetry of muscle activity increased while wearing spandex underwear. Conclusion: Spandex underwear has an effect that can reduce asymmetry of right and left muscles which are relevant to leg because spandex underwear equally supports right and left low-back muscles. Application: The spandex underwear used in this study can apply to the rehabilitation as an useful assistive device.

• Korean Journal of Applied Biomechanics
• /
• v.24 no.4
• /
• pp.445-453
• /
• 2014

The purpose of this study was to analyze the gait characteristics and interaction between lower extremity joints according to shoe's heel heights in young women. Participants were selected as subject consisted of young and healthy women (age: $23.71{\pm}1.49yrs$, height: $165.92{\pm}2.00cm$, body weight: $54.37{\pm}3.46kg$) and walked with 3 types of shoe's high-heel (0, 5, 9 cm). The variables analyzed consisted of the displacement of Y axis in center of mass ([COM]; (position, velocity), front rear(FR) and left right(LR) angle of trunk, lower extremity joint angle (hip, knee, ankle) and asymmetric index (AI%). The displacement of Y axis in COM position showed the greater movement according to increase of shoe's heel heights, but velocity of COM showed the decrease according to increase of shoe's heel heights during gait. The hip and knee angle didn't show significant difference statistically according to increase of shoe's heel height, but left hip and knee showed more extended posture than those of right hip and knee angle. Also ankle angle didn't show significant difference statistically, but 9 cm heel showed more plantarflexion than those of 5 cm and 0 cm. The asymmetric index (AI%) showed more asymmetric 9 cm heel than those of 0 cm and 5 cm. The FR and LR angle in trunk tilting didn't show significant difference statistically according to the increase of shoe's heel height during gait in young women.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.28 no.2
• /
• pp.7-14
• /
• 2022

Purposed: This study was conducted to find out by ultrasonic waves the thickness change of the deep abdominal muscles, such as transverse abdominal, internal oblique and external oblique when performing general bridge exercise on the stable surface (GBE), single-legged bridge exercise on the stable surface (BES), bridge exercise with a sling (SBE) and single-legged bridge exercise with a sling (SBS). Methods: The subject, 33 healthy adults(18 men and 15 women) in their 20s of V university in J city were subjected to take four postures of GBE, BES, SBE, and SBS. When performing each posture, the thickness of transverse abdominal, internal oblique and external oblique were measured by ultrasonic waves and analyzed by repeated measures of ANOVA. This significance level was set to be p<.05. Results: Muscle thickness was increased in the order of BES, SBE, and GBE in the external oblique, resulting in statistically significant differences(p<.001). The internal oblique was significantly thicker in SBE and SBS rather than in GBE, and was thicker in SBE and SBS rather than in BES (p<.01). The thickness of the transverse abdominal was significantly increased in SBS than in GBE (p<.01). Conclusion: As the result, it may be more effective for the trunk stabilization exercises to activate the internal oblique and transverse abdominal by applying both-legged or single-legged bridge exercise in slings.