Bio-Medical Materials and Engineering - Volume 8, issue 3-4

Article Type: Other

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 119-119, 1998

Article Type: Other

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 121-121, 1998

Authors: Paul, J.P.

Article Type: Research Article

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 123-135, 1998

Authors: Andriacchi, Thomas P.

Article Type: Research Article

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 137-143, 1998

Authors: Hattori, Tomokazu

Article Type: Research Article

Abstract: In order to investigate clinical significance of the body up–down acceleration, and to practically verify the relationship with the vertical component of the ground reaction force, 3D kinematic gait analysis was performed on normal subjects and hip patients. The displacement of the body up–down movement was measured at the lower end of the sternum, then the acceleration was calculated from the displacement by using the double differential operation, and differential noise was removed by Finite Impulse Response (FIR) digital filter with the cutoff frequency of 3 Hz. The acceleration showed a regular cyclic pattern in normal subjects. However, in …hip patients, there was a significant decrease of downward acceleration at the mid‐stance of the affected side. And the acceleration was roughly consistent with the vertical component showing the same trends of up and down. However, in detail, they are inconsistent in the affected side, which is provably due to abnormal movements of the body and upper limbs, the so‐called compensational movements. Show more

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 145-154, 1998

Authors: Cheng, Cheng‐Kung | Chen, Hsiang‐Ho | Chen, Cheng‐Sheng | Lee, Shu‐Jen

Article Type: Research Article

Abstract: To more understand the influence of the walking speed on the spinal joint force distribution, a three‐dimensional biomechanical model was used to estimate the spine loads during human gait with three different walking speeds. This previously developed and validated model included a dynamic external model and an internal model with forces of disc, 8 major muscles, 2 ligaments and 2 facet joints at L_{5} /S_{1} level. A linear optimization method was used to solve the internal model to estimate the L_{5} /S_{1} spinal joint force distribution. The results of five young male subjects showed …that the mean peak L_{5} /S_{1} disc compressive forces on the slow, preferred and fast speeds were 2.28, 2.53, 2.95 body weight, respectively. The peak forces happened right after the heel strike and before completely toe off. The facet joint forces were generally increased with the walking speed increase, too. To reduce the loads on the spine, the slow walking is then recommended for the patients with low back pain or after spinal surgery. Show more

Keywords: Biomechanical model, gait, walking speed, lumbar spine

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 155-165, 1998

Authors: Isobe, Yasuyuki | Okuno, Makoto | Otsuki, Takeo | Yamamoto, Kichizo

Article Type: Research Article

Abstract: The present study was undertaken to serially observe gait of patients after hip arthroplasty, using quantitative gait analysis, and to compare it between patients after total hip arthroplasty (THA) and those after bipolar endoprosthetic arthroplasty (BEA). The subjects were 53 women with unilateral osteoarthritis of the hip. Thirty‐one of them underwent THA (mean age: 59.5 years) and 22 underwent BEA (mean age: 58.0 years). The stance time and characteristic parameters calculated from the vertical component of floor reaction force (FRF) were analyzed by use of FRF plate. The stance time, which indirectly represents the walking speed, tended …to decrease for one year after THA and for 3 years after BEA. The decrease in this parameter was greater on the unaffected side than on the affected side. The deceleration effect and the weighing‐off effect are indicators useful for observation of gait recovery. Significant differences in these indicators between the unaffected and affected sides were seen for one year after THA and 3 years after BEA. This indicates that cadence and balance of the gait recovers earlier after THA than after BEA. Show more

Keywords: Gait analysis, floor reaction force, total hip arthroplasty, bipolar endoprosthesis, osteoarthritic hip

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 167-175, 1998

Authors: Watanabe, Hidetoshi | Shimada, Yoichi | Sato, Kozo | Tsutsumi, Yoshihiro | Sato, Mineyoshi

Article Type: Research Article

Abstract: Summary of background. Intertrochanteric varus osteotomy of the femur for hip osteoarthritis is expected to bring improved congruity and increased weight‐bearing surface area of the hip joint. Before surgery, we usually make a tracing on a paper using an anteroposterior roentgenogram of the hip to simulate the operating procedures and obtain better conditions in the hip. Nevertheless, there have been some cases in which this procedure does not provide satisfactory postoperative results in terms of relief of pain or locomotion, with long‐term limp due to weakness of the hip abductor muscle group and shortening of the leg. Objectives. To …confirm if the improved congruity and increased covering of the weight‐bearing surface area obtained by varus osteotomy can be actually reproduced during walking, and to evaluate the kinetic mechanism of the effects of this procedure using gait analysis. Methods. We measured the strength ratio of the hip abductor muscles as the percent of the opposite side, and analyzed the pelvic movement and data of dynamic electromyography (EMG) recorded during locomotion in 24 female patients who underwent unilateral intertrochanteric varus osteotomy of the femur for hip osteoarthritis, 30 non‐surgically‐treated female patients with hip osteoarthritis, and 54 healthy women. In the operated patients, the roentgenograms obtained during one‐legged stance on the affected side disclosed that 10 were positive for Trendelenburg’s phenomenon (T(+ ) group) and 14 were negative for Trendelenburg’s phenomenon (T(–) group). All subjects walked with bare feet at a comfortable pace on a walkway containing a force plate. Photo switches were placed in a walkway to measure the gait velocity and to determine the stance phase time of one gait cycle. Frontal and sagittal trajectories of body surface markers for computerized joint‐angle motion analysis were acquired using the Quick‐MAG system. EMG data for the gluteus maximus, gluteus medius, tensor fascia latae, and lateral hamstrings recorded using surface electrodes were integrated to quantify as the percent of maximum voluntary contraction (% MVC). Results. This study disclosed that the stance phase time was shorter and the strength ratio of the hip abductor muscles was lower in the operated patients than those in the other 2 groups, and the change of the pelvic obliquity was smaller and the % MVC of the gluteus medius and tensor fascia latae were greater than those in the normal subjects. The change of the pelvic tilt showed the same pattern with those of the pelvic obliquity. The T(+ ) group showed decreased strength ratio of the hip abductor muscles and increased % MVC for the gluteus medius and the tensor fascia latae compared to the T(–) group, but the changes of both the pelvic obliquity and pelvic tilt did not significantly differ in the 2 groups. Conclusion. This study showed the postoperative reappearance of the simulated conditions in the hip before varus osteotomy of the femur, providing evidence that the pelvis was horizontally maintained during walking due to decreased stance phase time and increased performance of the hip abductor muscles after this procedure. Show more

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 177-186, 1998

Authors: Tanaka, Yoshitaka

Article Type: Research Article

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 187-196, 1998

Authors: Koga, Yoshio

Article Type: Research Article

Keywords: Motion analysis, knee osteoarthrosis, thrust, risk factor

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 197-205, 1998

Authors: Muneta, Takeshi | Ogiuchi, Takashi | Imai, Shoji | Ishida, Akimasa

Article Type: Research Article

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 207-218, 1998

Authors: Yamamoto, Takahiro | Niwa, Shigeo | Hattori, Tomokazu | Honjo, Hiroshi

Article Type: Research Article

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 219-225, 1998

Authors: Delp, Scott L. | Arnold, Allison S. | Piazza, Stephen J.

Article Type: Research Article

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 227-240, 1998

Authors: Andrews, Brian J. | Davoodi, Rahman | Kamnik, Roman | Bajd, Tadej

Article Type: Research Article

Abstract: Skilled behavior is difficult or impossible to articulate explicitly by the performers. Likewise biomechanical models of skilled motor actions are often limited by the lack of knowledge of the underlying mechanisms. A ‘behavioral cloning’ technique is described, based on a trained artificial neural network (ANN), that precisely mimics an individual’s learned skill. In this paper the motor skill considered is that of paraplegics using their upper limbs whilst standing‐up with FES. In a group of eight paraplegics with complete spinal injuries, it was possible to develop clones that followed closely the observed behavior of the subjects. Each subject used a …unique and consistent voluntary control strategy. Subjects with more experience in using FES were more consistent in the use of their arms from trial to trial. Comparison of the clones revealed features suggestive of some common underlying voluntary control strategies. Show more

Citation: Bio-Medical Materials and Engineering, vol. 8, no. 3-4, pp. 241-251, 1998