• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.11
• /
• pp.107-118
• /
• 2008

In this study, lower extremity joint kinematics and kinetics and lumbar lordosis were investigated for two different symmetrical lifting techniques(squat and stoop) using the three-dimensional motion analysis. Twenty-six male volunteers lifted boxes weighing 5, 10 and 15kg by both squat and stoop lifting techniques. There were not significant differences in maximum lumbar joint moments between the two techniques. The hip and ankle contributed the most part of the support moments during squat lifting, and the knee flexion moment played an important role in stoop lifting. The hip, ankle and lumbar joints generated power and only the khee joint absorbed power in the squat lifting. The knee and ankle joints absorbed power, the hip and lumbar joints generated power in the stoop lifting. The bi-articular antagonist muscles' co-contraction around the knee joint during the squat lifting and the eccentric co-contraction of the gastrocnemius and semitendinosus were found to be important for straightening up during the stoop lifting. At the time of lordotic curvature appearance in the squat lifting, there were significant correlations in all three lower extremity joint moments with the lumbar joint. Differently, only the hip moment had significant correlation with the lumbar joint in the stoop lifting. In conclusion, the knee extension which is prominent kinematics during the squat tilling was produced by the contributions of the kinetic factors from the hip and ankle joints(extensor moment and power generation) and the lumbar extension which is prominent kinematics during the stoop lifting could be produced by the contributions of the knee joint kinetic factors(flexor moment, power absorption, bi-articular muscle function).

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.8
• /
• pp.104-110
• /
• 2008

The aim of this study ultimately is verifying that PGO gait is more efficient than RGO fur paraplegics because the air muscle assists hip flexion power in heel off movement. The gait characteristics of the paraplegic wearing the PGO or RGO are compared with that of a normal person. PGO with air muscles was used to analyze the walking of patients with lower-limb paralysis, and the results showed that the hip joint flexion and pelvic tilt angle decreased in PGO. In comparison to RGO gait, which is propelled by the movements of the back, PGO uses air muscles, which decreases the movement in the upper limb from a stance phase rate of 79$\pm$4%(RGO) to 68$\pm$8%. The energy consumption rate was 8.65$\pm$3.3 (ml/min/Kg) for RGO, while it decreased to 7.21t2.5(ml/min/Kg) for PGO. The results from this study show that PGO decreases energy consumption while providing support for patients with lower-limb paralysis, and it is helpful in walking for extended times.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.7 no.2
• /
• pp.101-107
• /
• 2013

In this paper, we were to investigate effect of correction to muscle imbalance in lower limbs according to reduction of weight bearing methods of four point of horizontal shaft using two-belt treadmill. Participants were divided to two group according to each ten peoples who have difference of muscle function in left and right legs over 20%. Experiment progressed forty minutes a day three days a week, total four weeks and we estimated the maximal peak torque and average power for testing joint torque in hip, knee and ankle. The results showed that the correction effect of muscle imbalance to the maximal muscle strength was the most effective in hip joint. Also in knee joint, correction effect of muscular reaction was the most effective too. We thought that reduction of weight bearing methods could be positive effect to correct muscle imbalance in lower limbs.

• Journal of The Korean Society of Integrative Medicine
• /
• v.3 no.2
• /
• pp.47-54
• /
• 2015

Purpose: This study was to investigate the effects of lumbar stabilization exercise and lower extremity strengthening program on pain, lower extremity muscle in patients with chronic low back pain. Method: The subject were randomly divided two groups. 15 people who were conducted lower extremity exercises and lumbar stabilization exercises called the combined exercise group and other(15 people) who were only conducted lower extremity exercise group. The assessment tools were the pain level and the led muscle power. Exercise was conducted for eight weeks. Result: Pain of the combined exercise group showed significant differences in the change in pain level(p<.05). The leg muscle power showed significant differences within group which hip flexor, extensor muscles and abductor muscles. there were significant differences within combined exercise group (p<.05). But the knee joint in each group showed a significant difference within group (p<.05). Conclusion: This study suggest that the lumbar stabilization exercises and lower extremity exercises showed more efficient results in the pain levels and leg muscles power than only the lower extremity exercise for patients with lumbar instability.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.9 no.1
• /
• pp.29-38
• /
• 2003

The purpose of this study was to investigate relationship of lumbar extensor muscle power & spinal column curve for old female patients with LDK(Lumbar degenerative kyphosis). Subjects were composed of 37 old female with LDK. The subjects were tested in their spinal segment movement and spinal column curve with Spinal-$Mouse^{\leq}$ in $1^{st}$ loaded test and $2^{nd}$ loaded test and then tested lumbar extensor muscle power with $Medx^{\leq}$ lumbar extension machine. The results of this study, were as follow; There were statistically significant difference $1^{st}$ loaded test and $2^{nd}$ loaded test in upright position increase spinal column forwardly(p<0.01) and decrease lumbar lordosis angle(p<0.01), but no statistically significant difference $1^{st}$ loaded test and $2^{nd}$ loaded test thoracic and hip & sacrum curve angle. Their lumbar extensor muscle poser is very weakness, 61.4% of normal people.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.9
• /
• pp.4008-4014
• /
• 2011

The purpose of this study was to identify the effect of muscular strength, sensation, and spasticity of the hip joint on balance using clinical tools in chronic stroke patients. Thirty-two subjects participated. It were measured muscular strength of the hip flexor, extensor, abductor, and adductor using manual muscle testing, light touch sensibility, and spasticity of the quadriceps using the modified Ashworth scale in the paretic lower extremity. Also, static and dynamic balance were measured by the functional balance scale. Collected data was analyzed by stepwise multiple regression. Muscular strength of the hip abductor, light touch sensibility, and spasticity were associated with static balance(p<0.05) and explanatory power was 80.5%. Muscular strength of the hip abductor and light touch sensibility were associated with dynamic balance(p<0.05) and explanatory power was 77.9%. Thus, it is suggested that muscular strength of the hip abductor and light touch sensibility is considered when providing evaluation and intervention programs for the future in the balance.

• Korean Journal of Applied Biomechanics
• /
• v.24 no.1
• /
• pp.59-66
• /
• 2014

The purpose of this study was to investigate the effects of knee joint muscle fatigue and overweight on shock absorption during single-leg landing of adult women. Written informed consent forms, which were approved by the human subject research and review committee at Dong-A University, were provided to all subjects. The subjects who participated in this study were divided into 2 groups: a normal weight group and an overweight group, consisting of 15 young women each. Both the normal weight group and the overweight group showed that use soft landing and ankle dominant strategy. The peak vertical ground reaction force, the knee joint absorption power, and eccentric work done, as the increase of knee joint muscle fatigue level, showed a decrease. And the hip joint absorption power and eccentric work done, as the increase of weight, was less than the overweight group showed the normal weight group. In conclusion, the accumulation of the knee joint muscle fatigue and the increase of body weight may lead to an increased risk of injury during landing.

• Korean Journal of Applied Biomechanics
• /
• v.24 no.2
• /
• pp.167-172
• /
• 2014

The purpose of this study was to investigate walking standard time and joint powers of the lower extremities on the changes of illuminations in the elderly women. Ten older women ($70.90{\pm}3.28$ years, $154.70{\pm}3.47$ cm, $53.80{\pm}5.39$ kg) with normal vision and no gait disabilities participated in this study. All the experiments were performed on a level walkway from low to high lighting (six conditions). A 3-dimensional motion capturing system, force-plate, and EMG were used to acquire and analyze walking motion, force, and muscle activity data; the sampling frequency was 100 Hz, 1000 Hz and 1000 Hz respectively. To test the differences on walking standard time and joint powers of the lower extremities between the six lighting conditions, one-way repeated ANOVAs were evaluated. The following results were drawn: First, mean standard time was about 1.3 sec/stride, and velocities were smaller with lighting increasing except 100 Lx. Second, the joint power patterns of ankle and knee were not consistent, but only hip joint power was a greatest in 6 Lx and a smallest in 400 Lx. Third, standard times(100 Lx<300 Lx, 400 Lx) were statistically significant, and hip joint max powers (100 Lx>others) were also statistically significant. But ankle and knee joint max power were not statistically significant. These results showed that standard times from low to high lighting were not consistent, and hip joint of 100 Lx has a greatest rotational torque. We suggested that gait strategies of them as to changing illuminations were not consistent and findings may represent a lack of adaptability in the elderly women.

• Journal of Community Nutrition
• /
• v.1 no.2
• /
• pp.98-107
• /
• 1999

The purpose of this study was to investigate Bone Mineral Density(BMD) and affecting factors on BMD of college women in Seoul. The subjects were 47 healthy college women aged 18-25 years. Antrophometric and body fat measurements were performed by Bioelectrical Impedance Fatness Analyzer(Tanita TVF 202). Blood pressure and pulse frequency were measured. Dietary intakes and general living habits were examined through questionnaires and nutrient intakes were analyzed by Computer Aided Nutritional Analysis(CAN) program for professional. Serum total cholesterol, TG(triglyceride), HDL-cholesterol, total protein, albumin, GOT, calcium were measured by Spotchem(SP-4410). Serum osteocalcin and alkaline phosphatase(ALP) were measured to monitor bone formation. BMD of lumbar spine(L2-L4), right hip(neck, ward's triangle, trochanter) and right forearm were measured by Dual Energy X-ray Absorptiometry(DEXA). Muscle strength was measured by examining leg flexion strength(right and left), leg extension power(right and left), handgrip power(right and left) and back strength. All data were statistically analyzed by the SAS PC package program. BMD of college women was normal(by WHO, 1994). Their muscle strength was bad(by national fitness guidebook, 1995). Only a mall number of them exercised (32.6% of subjects). There was no significant difference among BMD, muscle strength and % body fat(p<0.05). There were significant differences between BMD and total cholesterol as well as TG and VLDL-cholesterol(p<0.05). Total cholesterol was associated with decreasing BMD of the right forearm(p<0.05). TG and VLDL-cholesterol are associated with increasing BMD of right hip ward's triangle(p<0.05). There were significant differences among BMD, ALP and serum total protein. ALP was associated with decreasing BMD of the right forearm(p<0.05). There were significant differences between BMD and Ca as well as between Na and K intakes (p<0.05). Intakes of Na and K were associated with decreasing BMD of the right forearm (UD)(p<0.05). There were significant differences between in BMD and pulse frequently and serum albumin (p<0.05). Serum albumin is associated with increasing BMD of L3-L4(p<0.05), right hip neck(p<0.05). %Body fat, TG, VLDL-C, Ca intake, pulse frequency and serum albumin were associated with increasing BMD(p<0.05). Intakes of Na and K, ALP, total cholesterol, total cholesterol, total protein and height are associated with decreasing BMD(p<0.05). Overall results indicate that Ca intake but to be moderate in protein and Na intakes in order to increase BMD. Body exercise was recommended to increase BMD as well.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.6
• /
• pp.2691-2697
• /
• 2011

The purpose of the dissertation is to offer basic data available for being conducive to application of a training program by comparatively analyzing the players' physical strength, the knee joint, a hip joint, power of the trunk joint and muscle power in order to study isokinetic strength and muscle power between short distance athletes and Taekwondo players. This study measured peak power, %Body weight peak power, always power, and %Body weight peak power targeting 8 male athletes and 8 male Taekwondo players who warmed up 10 minutes before from the test to reduce repulsion and unfamiliarity at the instrument. The power of the knee joint($60^{\circ}$/sec), muscle power($180^{\circ}$/sec), were measured by using HUNOM(U.S.A). As a result of the physical strength, statistically, short distance athletes were indicated to be better in muscle strength, muscular endurance than Taekwondo players, and there was no significant difference between flexibility, power, and muscular endurance. Although the short distance athletes were indicated to be better in right and left muscle strength of knee joint than Taekwondo player, there was no significant difference and Taekwonde players were indicated to be higher at the right and left muscle power than short distance athletes.