• Korean Journal of Applied Biomechanics
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• v.22 no.2
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• pp.201-208
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• 2012

The purpose of this study was to investigate the effect of leg extension exercises performed on outdoor resistance exercise machines on knee extension muscle strength and quadriceps muscle group cross sectional area (CSA) in elderly women. Two groups were recruited for this study, including an exercise group (EG: n=13, $71.38{\pm}2.79$ yrs) and a control group (CG: n=5, $73.4{\pm}5.94$), In all subjects, maximum isometric and isokinetic muscle strength of knee flexion and extension were measured using an isokinetic dynamometer (Cybex(R) Humac Norm Testing & Rehabilitation System, USA). Quadriceps muscle group CSA were measured using MRI (Philps, Intera 1.5 T, NE Netherlands). The results of this study showed that post-intervention isometric knee extension peak torque value were higher than pre-intervention measures in the EG. However, the EG did not show improvement in quadriceps muscle group CSA, Also, no differences in the shift of optimal knee joint angle were observed between pre and post-intervention exercise. Outdoor leg extension exercise showed small increases in muscle strength in comparison to other resistance training exercises. The results of this study suggest that because outdoor leg extension exercise machines lack a progressive loading mechanism, significant increases in muscle strength may not be obtained.

• Korean Journal of Applied Biomechanics
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• v.16 no.4
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• pp.175-187
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• 2006

The purpose of this study was to find the relationship between Achilles tendon angle, angular velocity from 2D cinematography utilized to easily analyze the functions of shoes, ankle joint moment, knee joint moment, and hip joint moment from 3D cinematography utilized to predict the injury. Also, this study was to provide the optimal standard to analyze the injury related to the shoes. Subjects in this study were 30 university male students and 18 conditions (2 types of running speed, 3 of midsole hardness, 3 of midsole height) were measured using cinematography and force platform. The results were as following. 1) Hip joint abduction moment was effected by many variables such as running speed, midsole height, maximum achilles tendon angle, ground reaction force. 2) Knee joint rotational moment in running was approximately 1/10 - 1/4 times of the injury critical value and eversion moment was approximately 1/4 - 1/2 times of the injury critical value. 3) Ankle joint pronation moment in running was 1/3 - 1/2 times of the injury critical value. 4) Knee joint rotational moment was found to be irrelevant with maximum achilles tendon angle or angular velocity. 5) Pronation from running was thought to be relevant to rather eversion moment activity than rotational moment activity of knee joint. 6) Plantar flexion abductor of ankle showed significant relationship with the ground reaction force variable. 7) When the loading rate for ground reaction force in passive region increased, extensor tended to be exposed to the injury. Main variables in biomechanical analysis of shoes were impact absorption and pronation. Among these variables, pronation factor was reported to be relevant with knee injury from long duration exercise. Achilles tendon angle factor was utilized frequently to evaluate this. However, as the results of this study showed, the relationship between these variables and injury relating variable of knee moment was so important. Studies without consideration on this finding should be reconsidered and reconfirmed.

• Korean Journal of Applied Biomechanics
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• v.13 no.1
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• pp.13-21
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• 2003

The purpose of this study is (a) to estimate effective moment arms of quadriceps forces and (b) to compare the $d_e$ between the ACL-reconstructed and uninjured knees from the same individual. One female (20 yrs old, 2 yrs post-op, hamstring tendon autograft) and two males (22 yrs old, 2 yrs post-op; 28 yrs old, 4 yrs post-op; Patellar tendon autografts for both). Sagittal view radiographs were obtained for 6-7 different angles $(range\;5^{\circ}-110^{\circ})$ from each knee. The do was determined by the method of Chow et al. (1999a). The results showed that the maximum de values ranged from 4.61 to 5.59cm and 4.59 to 4.89cm for the ACL-reconstructed and uninjured knees, respectively. The maximum $d_e$ occurred between $35^{\circ}\;and\;50^{\circ}\;and\;20^{\circ}\;and\;50^{\circ}$ for the ACL-reconstructed and uninjured knees, respectively. The minimum do values ranged from 4.12 to 4.35 cm and 3.12 to 3.63cm for the ACL-reconstructed and uninjured knees, respectively. The effective moment arm of the knee extensor affects the loads on knee ligaments during knee-extension exercises. Because apparent differences in the moment arm of the quadriceps in different participants, it is very important to use personalized knee joint geometry for the computation of knee joint force. In the present study, no noticeable bilateral difference was found in the male subjects. However, apparent bilateral differences in de were observed in the female subject. This suggests that the effects of ACL reconstruction surgery on patellar mechanism deserve further investigation.

• The Journal of Korean Physical Therapy
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• v.33 no.3
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• pp.168-177
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• 2021

Purpose: This study applies the ICF to identify the patient's body function, structure, and participation, evaluates the patient's environmental factors and individual factors, and is a high level of movement to return to the society of patients with multiple ligament injury of the knee joint. Methods: Progressive strength training and ROM exercise were performed 30 minutes a day, 5 times a week for 6 weeks. The evaluation was performed by examining the ROM, length, MMT, instability, dynamic balance, pain and depression. Results: The ROM of the knee joint was improved from 110° to 135° after intervention, and the knee flexion length decreased from 69 cm to 45 cm. Knee flexor is Good after intervention from Poor-, and knee extensor is Good+ after intervention from Poor, and the plantar flexor of the ankle joint improved from Poor- before intervention to Good after intervention and dorsi-flexor of the ankle joint improve to Good from Poor. Pain index was moderate before and after the intervention, with a score of 3, 2 after the intervention, and when maintaining the sitting cross-legged, the before intervention score was 7 to 4 after the intervention. Conclusion: The patient's posture of sitting cross-legged was maintained from 30 seconds before intervention to 14 minutes after intervention. These results were able to set the hypothesis design, intervention method and goal that the multifaceted approach of environment and individual factors as well as body function and structure area, activity and participation area using ICF checklists, it is helped the patient to return to daily life.

• Physical Therapy Korea
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• v.8 no.3
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• pp.97-105
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• 2001

The purpose of this study was to investigate the effect of functional strengthening exercise on static and dynamic standing balance in a child with cerebral palsy. The subject was a 7 year old boy with diplegia whose Gross Motor Function Measure (GMFM) score was 80% along with G1 of the lower extremities in Modified Ashworth Scale. The subject was ambulatory with some degree of limitation and demonstrated muscle weakness and strength asymmetry in the lower extremities. A changing criterion design for a single-subject research was used for this study. The functional strengthening exercise consisted of lower extremity ergometer exercise and knee exercise with grading movement in standing position, each for 20 minutes, which lasted 18 sessions for 6 weeks. A knee extensor strength test on both extremities and standing balance test were conducted after each functional strengthening exercise. Two types of standing balance were tested: one leg stance test and functional reach test. One leg stance test was to evaluate static standing balance, and functional reach test was to evaluate dynamic standing balance. The results showed that the functional strengthening exercise had some positive effects on improvement of both static and dynamic standing balance, and there was a positive correlation between the knee strength and standing balance.

• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.2
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• pp.74-78
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• 2005

Even though, anterior knee pains are most frequently encountered in knee clinics, many physicians use a 'recipe'-type of approach to their treatment. But many predisposing factors have been included internal rotation of the femur, valgus knee alignment, external rotation of the extensor mechanism, patellar alta, a flat trochlear groove, patella with poor congruence and ligatmentous laxity. Many scientific principles on which these commonly used treatment are based, can lead to refinements and improvement in treatment. We reviewed and summarized the recent functional anatomical and biomechanical data that are most relevant to the contemporary treatment of patellofemoral joint disorders.

• Korean Journal of Applied Biomechanics
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• v.20 no.2
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• pp.175-182
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• 2010

The purpose of this study was to evaluate the biomechanical effect of sports taping on the lower limb during drop landing. Twelve male university students who have no musculoskeletal disorder were recruited as the subjects. Principal strain, median frequency, vertical GRF, loading rate, angular velocity and resultant joint moment were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between taped and untaped conditions(p<.05). The results showed that principal strain of the thigh and the shank in taping group were significantly less than those found in control group. These indicated that sports taping may prevent excessive mechanical strain caused by impact force during the deceleration phase. Flexion(-)-extension(+) and varus(-)-valgus(+) resultant joint moment of the knee joint in taping group were greater than corresponding value for control group. It seems that extensor muscle of the knee joint were not only supported by sports taping during knee flexion but also sports taping is effective for minimizing the possibility of injury.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.3
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• pp.477-485
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• 2010

Purpose : The clinical scale to assess spasticity of muscle was wildly used the modified Ashworth scale (MAS). But reliability of the MAS has been controverted for ambiguity among the grades. The purpose of this study was to establish the inter-rater reliability of the modified MAS (MMAS) translated into Korean in stroke patients. Methods : Twenty-five patients (sixteen men and nine women) with hemiplegia (ten right and fifteen left) were measured by two raters who were physical therapist in the rehabilitation hospital. The raters assessed spasticity of shoulder adductor, elbow flexor, wrist flexor, hip adductor, knee extensor, and ankle plantar flexor in the same patients according to ratings criteria of the MAS and the MMAS. Results : For the inter-rater reliability of the MAS, two raters agreed on 57.3% and the Kappa values were moderate ($\kappa$=0.41) between two rater. The inter-rater reliability of the MAS was fair for the wrist flexor and the hip adductor and moderate for the other muscles. The intra-rater reliability was good for the shoulder adductor and the knee extensor and moderate for the other muscles. For the inter-rater reliability of the MMAS, two raters agreed on 84.7% and the Kappa values were good ($\kappa$=0.78) between two rater. The inter-rater reliability of the MMAS was moderate for the hip adductor, and good for the shoulder adductor and the wrist flexor, and very good for the other muscles. The intra-rater reliability was good for the wrist flexor and the hip adductor and very good for the other muscles. Conclusion : This study suggests that the MMAS translated into Korean is reliable test scale for the spasticity with stroke patients in the clinical field.

• Physical Therapy Korea
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• v.20 no.3
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• pp.1-8
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• 2013

The purpose of this study was to determine the effectiveness of sit-to-stand training on unstable surfaces in individuals with stroke. Nineteen subjects with chronic stroke were divided into two groups: an experimental group (10 subjects) and a control group (9 subjects). They received 30 minutes of Neuro-developmental therapy (NDT) treatment, and sit-to-stand exercise for 15 minutes three times a week for four weeks. During the sit-to-stand training, the experimental group performed on an unstable AIREX balance pad, but the control group performed on a stable surface. Balance ability and weight-bearing distribution during quiet standing were measured before and after training period using the 7-item Berg balance scale-3P (BBS-3P) and the Five-times-sit-to-stand test (FTSST). In addition, the muscle strength of the knee extensor was evaluated before and after the training period. The results were as follows: 1) The weight-bearing distribution forward of the affected leg, increased significantly in the experimental group after the four-week intervention (p<.05), 2) The 7-item BBS-3P and FTSST increased significantly in the experimental group after the four-week intervention (p<.05), 3) The knee extensor muscle strength in both groups increased significantly after the four-week intervention (p<.05). In conclusion, the results of this study did not show that the sit-to-stand training on an unstable surface was more effective than on a stable surface. However, the results suggested that sit-to-stand training is effective in the balance training of stroke patients.

• Physical Therapy Korea
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• v.11 no.1
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• pp.19-25
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• 2004

The purpose of this study was to investigate the effects of backrests of varying degrees ($90^{\circ}$, $100^{\circ}$, $110^{\circ}$) on three abdominal muscles (upper rectus abdominis, external oblique, internal oblique) and back extensor activation during lower extremity exercise. The three different conditions during bilateral knee extention exercise were: (1) leaning on a chair with a $90^{\circ}$ backrest, (2) leaning on a chair with a $100^{\circ}$ backrest, (3) leaning on a chair with a $110^{\circ}$ backrest. Fifteen healthy muscle subjects (mean age=24.2 years [SD=2.96], mean height=175.6 cm [SD=7.46], mean weight=69.1 kg [SD=7.36]) with no history of neuromusculoskeletal disease voluntarily participated in this study. Electromyography was used to collect muscle activation, and the muscle activation was expressed as a percentage of maximal voluntary isometric contraction (%MVIC). Repeated one-way analysis of variance (ANOVA) was used to determine the statistical significance. The results were as follows: (1) upper rectus abdominis, external oblique, internal oblique activation measured significantly lower. (2) measured significantly lower when lower degree.