의지 보행시 의지 무게 분포가 근골격계에 미치는 영향

배태수(Tae Soo Bae),최환(Hwan Choi),김신기(Shin Ki Kim),문무성(Mu Seong Mun) Korean Society for Precision Engineering 2007 한국정밀공학회지 Vol.24 No.8

The optimized prosthetic mass distribution was a controversial problem in the previous studies because they are not supported by empirical evidence. The purpose of the present study was to evaluate the effect of prosthetic mass properties by modeling musculoskeletal system, based on the gait analysis data from two above-knee amputees. The joint torque at hip joint was calculated using inverse dynamic analysis as the mass was changed in knee and foot prosthetic components with the same joint kinematics. The results showed that the peak flexion and abduction torque at the hip joint were 5 Nm and 15 Nm when the mass of the knee component was increased, greater than the peak flexion and abduction torque of the control group at the hip joint, respectively. On the other hand, when the mass of the foot component was increased, the peak flexion and abduction torque at the hip joint were 20 Nm and 15 Nm, greater than the peak flexion and abduction torque of the control, respectively. The hip flexion torque was 4.71-fold greater and 7.92­fold greater than the hip abduction torque for the knee mass increase and the foot mass increase on the average, respectively. Therefore, we could conclude that the effect of foot mass increase was more sensitive than that of knee mass increase for the hip flexion torque. On the contrary, the mass properties of the knee and foot components were not sensitive for the hip abduction torque. In addition, optimized prosthetic mass and appropriate mass distributions were needed to promote efficiency of rehabilitation therapy with consideration of musculoskeletal systems of amputees.

근골격 모델을 이용한 대퇴절단환자의 계단보행에 대한 동역학 해석

배태수(Tae Soo Bae),김신기(Shin Ki Kim),문무성(Mu Seong Mun) Korean Society for Precision Engineering 2007 한국정밀공학회지 Vol.24 No.7

It is important to understand the characteristics of amputee gait to develop more advanced prostheses. The aim of this study was quantitatively to analyze the stair climbing task for the above-knee amputee with a prosthesis and to predict muscle forces and joint moments at musculoskeletal joints by dynamic analysis. The three-dimensional musculoskeletal model of lower extremities was constructed by gait analysis and transformation software for one above-knee amputee and ten healthy people. The measured ground reaction forces and kinematical data of each joint by gait analysis were used as input data during inverse dynamic analysis. Lastly, dynamic analysis of above-knee amputee during stair climbing were performed using musculoskeletal models. The results showed that summed muscle forces of hip extensor of amputated leg were greater than those of sound leg but the opposite results were revealed at hip abductor and knee flexor of amputated leg. We could also find that the higher moments at hip and knee joint of sound leg were needed to overcome the flexion moment caused by body weight and amputated leg. In conclusion, dynamic analysis using musculoskeletal models may be a useful mean to predict muscle forces and joint moments for specific motion tasks related to rehabilitation therapy.

무릎관절에서의 단계별 도수견인에 따른 견인력과 연성변이와의 관계

배태수(Tae Soo Bae),허현(Hyun Heo),김경훈(Kyung Hun Kim),안재용(Jae Yong Ahn) Korean Society for Precision Engineering 2008 한국정밀공학회지 Vol.25 No.4

Although manual traction, one of pain therapies, was applied in clinic to relief pain, the study was rare on the manual force and displacement of ligaments at knee joint during manual traction. The aim of this study is to quantify not only manual force at knee joint but also elongated displacement of joint ligament by C-arm scanning and motion analysis. Twenty-one healthy subjects were tested with manual traction from grade Ⅰ to grade Ⅲ under neutral position by a physical therapist. We calculated traction force using joint forces of both hands and elongated displacement of joint ligament were measured. The results showed that traction forces by C-arm scanning analysis were averagely 1.67-fold greater than those by motion analysis, but elongated displacements were instead averagely 2.36-fold smaller than motion analysis. Finally, we could estimate relationship between traction force and elongated displacement at knee joint by two methods.

Evaluation of Dynamic Operating Performance of Rotary Hydraulic Cylinder by Moving Particles Semi-implicit Method

Tae Soo Bae(배태수),Woong Cho(조웅) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.4

근골격계 모델을 이용한 요추전만 각도 변화가 요추관절에 미치는 영향 분석

배태수(Tae Soo Bae),김신기(Shin Ki Kim),류제청(Je Chung Ryu),문무성(Mu Seong Mun) Korean Society for Precision Engineering 2009 한국정밀공학회지 Vol.26 No.10

It is important to consider lumbar lordotic angle for setup of training program in field of sports and rehabilitaton to prevent unexpected posture deviation and back pain. The purpose of this study was to analyze the biomechanical impact of the level of lumbar lordosis angle during isokinetic exercise through dynamic analysis using a 3-dimensional musculoskeletal model. We made each models for normal lordosis, excessive lordosis, lumbar kyphosis, and hypo-lordosis according to lordotic angle and inputted experimental data as initial values to perform inverse dynamic analysis. Comparing the joint torques, the largest torque of excessive lordosis was 16.6% larger and lumbar kyphosis was 11.7% less than normal lordosis. There existed no significant difference in the compressive intervertebral forces of each lumbar joint (p>0.05), but statistically significant difference in the anterioposterior shear force (p<0.05). For system energy, lumbar kyphosis required the least and most energy during flexion and extension respectively. Therefore during the rehabilitation process, more efficient training will be possible by taking into consideration not simply weight and height but biomechanical effects on the skeletal muscle system according to lumbar lordosis angles.

동물실험용 골융합 임플란트 시스템 개발

배태수(Tae Soo Bae),허현(Hyun Heo),김신기(Shin Ki Kim),문무성(Mu Seong Mun),안재용(Jae Yong Ahn),홍성란(Sung Ran Hong) Korean Society for Precision Engineering 2007 한국정밀공학회지 Vol.24 No.10

The novel implant system was developed using osseo-integration technology which enable amputee to overcome skin troubles in use of previous socket system and was evaluated in view of biomechanics, radiology, histology, and pathology. The osseo-integrated implants were designed and manufactured using CT image of canine’s tibia and were applied to laboratory animals(canines). The follow-up studies were performed for 24 months with 10 canines. In radiology examination, we found that the relative low strain distribution caused medial and posterior bone resorption and then we verified them by biomechanical testing. In histological approach, the complete osseo-integration was observed through the activity of osteoblast cells around bone-implant interface and the radial outer region of bone due to peristeum reaction. Lastly in pathological aspect, the evidence of superficial infection was detected but that of deep infection was not. Therefore it is thought that infection problem will be overcome by immunity of body and good hygiene.

Evaluation of Joint Load as Pre-Operative Traction in Fracture Reduction Surgeries of Femur and Tibia

배태수(Tae Soo Bae),조병찬(Byeong Chan Cho),한재웅(Jae Woong Han) Korean Society for Precision Engineering 2019 한국정밀공학회지 Vol.36 No.10

Safe pre-operative traction applied and maintained to the fractured site in fracture reduction surgery is crucial. However, existing traction techniques performed by clinicians or manual traction devices are not elaborate and have no traction force information considering differences in patients’ bodies. The purpose of this study was to evaluate joint loads of fractured sites as pre-operative traction forces considering body mass index (BMI) during fracture reduction surgeries using a robotassisted device. We developed a lower-extremity dummy model to measure joint loads at hip, knee, ankle, and fractured sites. In 240 cases, four BMI types, six traction forces and two fractured sites were used. Results showed that joint load on major joints decreased as BMI increased. Additionally, joint load increased proportionally in the fractured tibia, but showed inverse tendency in the fractured femur. Control errors of up to 20% in repetitive control and approximately 30% in random control were measured, in comparison to estimated joint loads. Control error increased as traction force decreased. It is possible that applicability of robot systems to safe and precise surgical assistance can be validated. More precise traction control and real-time traction load monitoring technology will enable replacement of traction techniques in the near future.

인공의족의 외반 특성이 하퇴절단자의 무릎과 발목에 미치는 영향

배태수(Tae Soo Bae),장윤희(Yun Hee Chang),김신기(Shin Ki Kim),문무성(Mu Seung Mun) 대한기계학회 2009 大韓機械學會論文集A Vol.33 No.9

One of the important functions of prosthetic foot is the foot inversion-eversion which is so important when walking on uneven surfaces. The aim of our study was to evaluate the effect of foot eversion angle especially on knee and ankle joint for transtibial amputees by motion analysis. The experimental data were collected from three transtibial amputees and then ten healthy individuals. To simulate walking on side sloping ground, we used custom-made slope (5, 10, 15 degrees). Motion analysis was performed by 3-dimensional motion analyzer for 6 dynamic prosthetic feet. The results showed that knee abduction moments of amputated leg were decreased but those of sound leg were mainly increased as foot eversion angle increased. And ankle abduction moments of sound leg were inconsistent in magnitude and tendency between control and experimental group. Therefore foot eversioncharacteristics should be considered to develop advanced prosthetic foot.

다채널 진동자극이 체성감각에 미치는 영향

배태수(Tae Soo Bae),김형재(Hyung Jae Kim),김솔비(Sol Bi Kim),장윤희(Yun hee Chang),김신기(Shin Ki Kim),문무성(Mu Seong Mun) Korean Society for Precision Engineering 2011 한국정밀공학회지 Vol.28 No.6

Although prosthetic training was received, most of amputees mainly depend on visual feedback to use prostheses, not on cutaneous and proprioceptive sensibility. Our objective of this study was to determine if there are changes in the somatosensory sensibility of amputees compared to non-amputees using multi-channel vibration stimulation system. One transradial amputees and ten non-amputees were involved. To investigate changes of residual somatosensory sensibility at stump, we set up custom-made vibration stimulation system including eight actuators (4 medial and 4 lateral) and GUI-based acquisition system. The results showed that there was similar pattern of subjective response at most of channels among group as stimulation increases. However, amputees’ subjective response at channel 8 for 238㎐ vibration was more sensitive than that of healthy persons. With respect to channels, response at channel 4 (medial) corresponding region to flexor carpi ulnaris for transradial amputees was most sensitive than other channels. In addition, sensitivity of four medial channels was on average about 0.5 scale than that of four lateral channels. Somatosensory sensibility was amputee, women, and men in sensibility order.

인공의족의 외반 특성이 하퇴절단자의 무릎과 발목에 미치는 영향

배태수(Tae Soo Bae),장윤희(Yun Hee Chang),김신기(Shin Ki Kim),문무성(Mu Seung Mun) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

One of the important functions of prosthetic foot is the foot inversion-eversion which is so important when walking on uneven surfaces. The aim of our study was to evaluate the effect of foot eversion angle especially on knee and ankle joint for transtibial amputees by motion analysis. The experimental data were collected from three transtibial amputees and then ten healthy individuals. To simulate walking on side sloping ground, we used custom-made slope (5, 10, 15 degrees). Motion analysis was performed by 3-dimensional motion analyzer for 6 dynamic prosthetic feet. The results showed that knee abduction moments of amputated leg were decreased but those of sound leg were mainly increased as foot eversion angle increased. And ankle abduction moments of sound leg were inconsistent in magnitude and tendency between control and experimental group. Therefore foot eversioncharacteristics should be considered to develop advanced prosthetic foot.