• Title, Summary, Keyword: Knee

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Control of an above-knee prosthesis using MR damper (MR 감쇠기를 이용한 무릎 관절 의족의 제어)

  • 김정훈;오준호
    • 제어로봇시스템학회:학술대회논문집
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    • pp.244-244
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    • 2000
  • We proposed the above-knee prosthesis using rotary MR damper in which knee joint is semi-actively controlled by microprocessor. Dissipation torque in the knee joint can be controlled by the magnetic field which is induced by applying current to a solenoid, Tracking control of knee joint angle was tested by 3-DOF Leg simulator. The experimental results show that the proposed above-knee prosthesis system had good performance in swing phase tracking and repetitive controller in conjunction with a computed control law and PD control law, reduced RMS tracking error as the repetitions of tracking. Moreover, desired knee angle trajectory was generated based on the estimation of gait period with the gyro signal and the tracking control was performed.

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The Knee Joint Position Sense in Healthy Women (정상 성인 여성의 무릎관절 위치감각)

  • Yang, Kyung-Hye;Lee, Hyun-Ok
    • PNF and Movement
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    • v.8 no.1
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    • pp.31-39
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    • 2010
  • Purpose : The purpose of this study is to ascertain whether age, body mass index(BMI) and exercise frequency(EF) are correlated with knee joint position sense in healthy women. Methods : Healthy women of 150 who participated in this study were tested knee joint position sense; each reposition error was analyzed according to the age, BMI and EF. Reposition error was measured with a Myrin goniometer. Results : The age groups, BMI groups and EF groups demonstrated significant differences of the knee joint position sense. The older the healthy women are, the higher BMI is, and the lower EF is, the more decreased knee joint position sense has become. Conclusion : The older the women are, the higher BMI is, and the lower EF is, the more decreased the knee joint position sense in healthy women is. Therefore it needs to be considered to require management of obesity and regular exercise for prevention of knee injuries due to decreased joint position sense.

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Effect of Moxibustion Therapy on the Degenerative Arthritis of Knee Joint with Osteochondroma (골연골종을 동반한 퇴행성 슬관절염에 구법(灸法)이 미치는 영향)

  • Oh, Myung Jin;Song, Ho Sueb
    • Journal of Acupuncture Research
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    • v.29 no.6
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    • pp.111-117
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    • 2012
  • Objectives : This study was done for reporting effect of moxibustion therapy on the degenerative arthritis of knee joint with osteochondroma. Methods : Two patient with degenerative arthritis of knee joint with osteochondroma was treated by moxibustion therapy. We applied moxibustion therapy three times a day for 12 days(three days per week). To investigate effectiveness of treatment we used visual analogue scale, Korean Western Ontario and McMaster Universities. Results : 1. The moxibustion therapy deceased knee joint pain. 2. As a result of evaluation by visual analogue scale, Korean Western Ontario and McMaster Universities the score marked lower than before treatment and after treatment. Conclusion : Moxibustion therapy decreased knee joint pain that patient have degenerative arthritis of knee joint with osteochondroma.

A Comparison of Sex-based Differences in Knee Neuromuscular Biomechanical Factors during Basketball Rebound Jump (농구 리바운드 점프 후 착지 시 성별에 따른 무릎의 근신경 생체역학적 요인의 차이 규명)

  • Lim, Bee-Oh;Park, Yong-Hyun
    • Korean Journal of Sport Biomechanics
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    • v.17 no.3
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    • pp.23-29
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    • 2007
  • The purpose of this study were to investigate the differences between female and male basketball players in knee neuromuscular biomechanical factors during basketball rebound jump. Twelve high school female ($17.9{\pm}0.8years$) and twelve male ($19.0{\pm}1.6years$) basketball players rebound jumped for maximal vertical height to sufficiently stress the anterior cruciate ligament. Kinematic and ground reaction data were collected and combined with inverse dynamics to estimate the knee extensor and abductor torque. The EMG data from the biceps femoris and rectus femoris was used to estimate the ratio of quadriceps muscle activity. Female athletes showed more reduced knee flexion at foot contact, more increased knee abduction, extensor and abductor knee joint torque at foot contact, and quadriceps ratio at stance phase than those of male athletes. In conclusion, Female athletes showed differences in knee neuromuscular biomechanical factors than male athletes during basketball rebound jump.

Novel computational approaches characterizing knee physiotherapy

  • Kim, Wangdo;Veloso, Antonio P.;Araujo, Duarte;Kohles, Sean S.
    • Journal of Computational Design and Engineering
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    • v.1 no.1
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    • pp.55-66
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    • 2014
  • A knee joint's longevity depends on the proper integration of structural components in an axial alignment. If just one of the components is abnormally off-axis, the biomechanical system fails, resulting in arthritis. The complexity of various failures in the knee joint has led orthopedic surgeons to select total knee replacement as a primary treatment. In many cases, this means sacrificing much of an other-wise normal joint. Here, we review novel computational approaches to describe knee physiotherapy by introducing a new dimension of foot loading to the knee axis alignment producing an improved functional status of the patient. New physiotherapeutic applications are then possible by aligning foot loading with the functional axis of the knee joint during the treatment of patients with osteoarthritis.

Comparison of Knee Extensor and Hip Extensor Strength According to Wall Squat Performance

  • Jung, Sung-hoon;Kim, Moon-hwan;Hwang, Ui-jae;Kim, Jun-hee;Kwon, Oh-yun
    • Physical Therapy Korea
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    • v.24 no.1
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    • pp.79-85
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    • 2017
  • Background: The wall squat is considered an effective exercise because it can reduce the knee load and prevent excessive lumbar movement. However, the relationship between wall squat performance and strength of knee extensors and hip extensors remained unclear. Objects: The purpose of this study was to compare the strengths of the knee extensors and hip extensors between groups with low and high wall squat performance. Method: Nineteen males (low performance group: 9 subjects, high performance group: 10 subjects) participated in this study and performed wall squats. The subjects who were performing less than 30% of the average wall squat count were classified into the low wall squat performance group (less than or equal to 4 times) and the subjects who performed more than 30% of the average wall squat count were classified into the high wall squat performance group (greater than or equal to 8 times). Knee extensor and hip extensor strength were measured with a strength measurement system. An independent t-test was used to compare the strengths of the knee extensors and hip extensors between the groups with low and high wall squat performance. Results: The ratios of knee extensor and hip extensor strength to bodyweight were greater in the high wall squat performance group than in the low wall squat performance group (knee extensors: p<.001; hip extensors: p=.03). In the high- and low-performance groups, the ratios of knee extensor strength to bodyweight were $42.74{\pm}5.72$ and $30.76{\pm}8.54$, respectively, and the ratios of hip extensor strength to bodyweight were $31.95{\pm}10.61$ and $20.66{\pm}11.25$, respectively. Conclusion: Our findings suggest that knee extensor and hip extensor strength are needed for high wall squat performance. Thus, exercise to increase the knee and hip extensors strength can be recommended to improve squat performance.

The Effects of Different Angles of Wedged Insoles on Knee Varus Torque in Healthy Subjects

  • Jung, Do-Young;Kwon, Oh-Yun;Yi, Chung-Hwi;Kim, Young-Ho;Kim, Jang-Hwan
    • Physical Therapy Korea
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    • v.11 no.4
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    • pp.31-41
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    • 2004
  • The purpose of this study was to examine the effect of the angle of a wedged insole on knee varus torque during walking. Fifteen healthy subjects were recruited. Knee varus torque was measured using three-dimensional motion analysis (Elite). Knee varus torque was normalized to gait cycle (0%: initial contact; 100%: ipsilateral initial contact) and stance phase (0%: initial contact; 100%: ipsilateral toe off). The average peaks of knee varus torque during the stance phase of the gait cycle according to the different insole angles (10 or 15 degrees) were compared using one-way ANOVA with repeated measures. The results showed that in the early stance phase, the average peak knee varus torque increased significantly for both the medial 10 and 15 degree wedged insole conditions and decreased significantly for both the lateral 10 and 15 degree wedged insole conditions as compared with no insole (p<.05). However, there were no significant differences between the 10 and 15 degree wedged insole conditions with either the medial or lateral wedged insole (p>.05). In the late stance phase, the average peak knee varus torque increased significantly for the medial 10 and 15 degree wedged insole conditions (p<.05), but not for the lateral 10 and 15 degree wedged insole conditions as compared with no insole (p>.05). We suggest that these results may be beneficial for manufacturing foot orthotic devices, such as wedged insoles, to control medial and lateral compartment forces in the knee varus-valgus deformity. Further studies of the effects of wedged insole angle on knee varus torque in patients with medial-lateral knee osteoarthritis are needed.

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Development of a Knee Exoskeleton for Rehabilitation Based EMG and IMU Sensor Feedback (단계별 무릎 재활을 위한 근전도 및 관성센서 피드백 기반 외골격 시스템 개발)

  • Kim, Jong Un;Kim, Ga Eul;Ji, Yeong Beom;Lee, A Ram;Lee, Hyun Ju;Tae, Ki Sik
    • Journal of Biomedical Engineering Research
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    • v.40 no.6
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    • pp.223-229
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    • 2019
  • The number of knee-related disease patients and knee joint surgeries is steadily increasing every year, and for knee rehabilitation training for these knee joint patients, it is necessary to strengthen the muscle of vastus medialis and quadriceps femoris. However, because of the cost and time-consuming difficulties of receiving regular hospital treatment in the course of knee rehabilitation, we developed knee exoskeleton using rapid prototype for knee rehabilitation with feedback from the electromyogram (EMG) and inertia motion unit (IMU) sensor. The modules was built on the basis of EMG and an IMU sensor applied complementary filter, measuring muscle activity in the vastus medialis and the range of joint operation of the knee, and then performing the game based on this measurement. The IMU sensor performed up to 97.2% accuracy in experiments with ten subjects. The functional game contents consisted of an exergaming platform based on EMG and IMU for the real-time monitoring and performance assessment of personalized isometric and isotonic exercises. This study combined EMG and IMU-based functional game with knee rehabilitation training to enable voluntary rehabilitation training by providing immediate feedback to patients through biometric information, thereby enhancing muscle strength efficiency of rehabilitation.

Efficacy of a Knee Walker for Foot and Ankle Patients: Comparative Study with an Axillary Crutch (족부 족관절 환자에서 Knee Walker의 유용성: 액와 목발(Axillary Crutch)과의 비교 연구)

  • Song, Jae Hwang;Kang, Chan;Kim, Sang Bum;Heo, Youn Moo;Won, You Gun;Jung, Sang Jin;Chung, Hyung Jin
    • Journal of Korean Foot and Ankle Society
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    • v.22 no.3
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    • pp.100-104
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    • 2018
  • Purpose: An axillary crutch is the most commonly used assistive device in foot and ankle patients who require nonweightbearing. On the other hand, its use frequently induces axillary or wrist pain and critical neurovascular injuries have been reported in several studies. This study compared the clinical outcomes of patients using the knee walker and axillary crutch. Materials and Methods: A retrospective analysis was performed comparing the utility of a knee walker and axillary crutch as a nonweightbearing ambulatory aid for 62 foot and ankle patients treated between November 2016 and March 2018. A comparative study of the two orthosis could be performed because all the patients temporarily used an axillary crutch before or after the use of a knee walker. A demographic study and comparative analysis based on the visual analogue scale (VAS) satisfaction score (0~100), complications, and fall down history were evaluated. Furthermore, under the assumption of having retreatment, their preference of orthosis between the knee walker and axillary crutch was investigated. Results: The mean age of the patients was 36.5 and the mean duration of ambulation with a knee walker and axillary crutch were 5.2 and 2.4 weeks. The VAS satisfaction score of the knee walker and crutch was 88.8 and 27.5, respectively (p<0.05). The most frequent complications of the knee walker and crutch were ipsilateral knee pain (6 cases) and axillary or wrist pain (56 cases), respectively. No case of falling down occurred during knee walker ambulation, but there were two cases of crutch ambulation. Fifty-eight patients (93.5%) preferred the knee walker and four patients (6.5%) preferred a crutch. Conclusion: Compared to the axillary crutch, the knee walker afforded lower complication and higher satisfaction. Most patients preferred the knee walker to a crutch. Therefore, the knee walker is an efficient and safe orthosis for foot and ankle patients who require nonweightbearing.

Prevalence and Related Factors of Knee Osteoarthritis in Rural Woman (농촌지역 여성들의 무릎 골관절염 유병률 및 관련요인)

  • Kang, Pock-Soo;Kim, Seok-Beom;Lee, Kyeong-Soo;Yun, Sung-Ho
    • Journal of Preventive Medicine and Public Health
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    • v.34 no.4
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    • pp.331-336
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    • 2001
  • Objectives : To assess the prevalence of knee osteoarthritis through proper diagnosis in a rural community and to elucidate the relevant factors of this health problem in order to develop educational methods for the prevention of female knee osteoarthritis as well to provide basic data for prospective research. Methods : Over a period of three months starting from August, 2000, 432 women over the age of 40 and living in a rural area were selected by a multistage cluster sampling method in order to investigate the prevalence of knee osteoarthritis and the related factors. The study utilized interviews and radiological examination. The criteria of knee osteoarthritis used was the American College of Rheumatology classification criteria for osteoarthritis of the knee(1995). Results : The adjusted prevalence of knee osteoarthritis among the subjects was 55.0%, and multiple logistic regression analysis showed that the odds ratio(OR) of knee osteoarthritis among subjects 50-59 years of age and subjects older than 60 years of age as compared to subjects 40-49 years of age were 2.43(95% CI: 1.30-4.70) and 4.40(95% CI: 2.47-7.83), respectively. The OR of knee osteoarthritis among factory workers or farmers as compared to others was 1.79(95% CI: 1.03-3.12). The OR of knee osteoarthritis among subjects who had a family history and subjects who had knee injury or surgical history against those subjects had neither were 2.56(95% CI: 1.42-4.03) and 4.70(95% CI:1.45-15.19), respectively. The OR of knee osteoarthritis among smokers against non smokers was 0.47(95% CI: 0.22-0.97). Conclusions : Related factors of knee osteoarthritis included age, occupation, family history, smoking, knee injury and history of surgery In order to prevent knee osteoarthritis in high risked rural woman, education concerning self-care methods and safety guideline must be provided at the work place by the public and private health sectors. Additionally, these women should be continually encouraged to exercise, including jogging and swimming regularly.

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