The effect of visual cues on muscular activation in the lower limbs of Parkinson's disease patients with freezing of gait: a preliminary study.

Freezing of gait (FOG) is a disabling symptom of Parkinson's disease (PD) patients, especially in advanced stages. Visual cues, such as the laser, have been confirmed to improve kinematic performance and alleviate FOG incidences. However, the muscular effect is unknown.

Local Dynamic Stability of the Locomotion of Lower Extremity Joints and Trunk During Backward Upslope Walking.

Backward slope walking was considered as a practical rehabilitation and training skill. However, its gait stability has been hardly studied, resulting in its limited application as a rehabilitation tool. In this study, the effect of walking direction and slope grade were investigated on the local dynamic stability of the motion of lower extremity joints and trunk segment during backward and forward upslope walking (BUW/FUW).

Hip joint geometry effects on cartilage contact stresses during a gait cycle.

The cartilage surface geometry of natural human hip joint is commonly regarded as sphere. It has been widely applied in computational simulation and hip joint prosthesis design. Some new geometry models have been developed and the sphere assumption has been questioned recently.

Local dynamic stability of the trunk segments and lower extremity joints during backward walking.

Backward walking has become a popular training method in physical exercise and clinical rehabilitation. For the sake of safety, it is important to keep a stable gait during backward walking. However, the gait stability during backward walking was rarely studied.

Effect of active arm swing to local dynamic stability during walking.

Arm swing is an essential component in regulating dynamic stability of the whole body during walking, while the contribution of active arm swing to local dynamic stability of different motion segments remains unclear. This study investigated the effects of arm swing under natural arm swing condition and active arm swing condition on local dynamic stability and gait variability of the trunk segments (C7 and T10 joint) and lower extremity joints (hip, knee and ankle joint). The local divergence exponents (λs) and mean standard deviation over strides (MeanSD) of 24 young healthy adults were calculated while they were walking on treadmill with two arm swing conditions at their preferred walking speed (PWS).

Kinematic characteristics of gait in middle-aged adults during level walking.

Middle-aged people have shown a high fall incidence and degeneration in gait stability, while few studies concern that. This study aimed to assess the kinematic characteristics of gait in middle-aged people compared with younger and older ones during level walking, and to find sensitive indicators to characterize degenerated gait stability in middle-aged people. 13 middle-aged (mean age=52.

Local dynamic stability of lower extremity joints in lower limb amputees during slope walking.

Lower limb amputees have a higher fall risk during slope walking compared with non-amputees. However, studies on amputees' slope walking were not well addressed. The aim of this study was to identify the difference of slope walking between amputees and non-amputees.

Contribution of arm swing to dynamic stability based on the nonlinear time series analysis method.

It is human nature to swing their arms at the frequency of leg motion during walking, but the contribution of arm swing to dynamic stability of human motion segments was poorly understood. Based on the nonlinear time series analysis method, the objective of this study was to investigate the effects of arm swing in three conditions (natural, active and restricted arm swing) on the dynamic stability of spine and lower extremity joints, and to further assess the contribution of arm swing to the human dynamic stability in relation with age. Gait experiments were carried out for 10 young and 8 middle-aged healthy volunteers while walking with natural, active and restricted arm swing.

Contributions of non-spherical hip joint cartilage surface to hip joint contact stress.

The natural non-spherical incongruent hip joint cartilage surface is normally assumed as spherical in shape, which has been extensively applied in orthopedic clinic, hip joint simulation studies and hip joint prosthesis design. The aim of the study was to investigate the contributions of non-spherical incongruent hip joint cartilage surface to the hip joint contact stress, and to assess the effect of simplified spherical assumption on the predicted contact stress. Based on our previous anatomic studies that the acetabular cartilage surface was demonstrated as rotational ellipsoid in shape, three finite element (FE) models involving the natural hip joint cartilage shape, the hip joint cartilage shape replaced by the rotational ellipsoid and the sphere, respectively, were developed using the computed tomography (CT) image data of healthy volunteers.

The shape of the acetabular cartilage surface and its role in hip joint contact stress.

The acetabular cartilage is normally represented as a spherical shape in orthopedic clinic and related researches. The aim of the study was to present a new mathematic representation with better fit to the acetabular cartilage surface and to investigate the role of its shape on the hip joint contact stress.

Computer-assisted orthopedic diagnosis and preoperative planning system based on the integrated electronic patient record.

Computer-assisted orthopedic diagnosis and preoperative planning have been recognized as efficient tools to improve the accuracy of clinic diagnosis and surgical procedure. In orthopedic clinic, such practices are heavily relied on the patient-specific medical image data.

[Computerized three-dimensional reconstruction and morphologic measurement of adult acetabulum bone structure].

Objective: To set up three-dimensional reconstruction of acetabulum bone structure from CT scanned image in computer with software of CAD and study quantitatively the morphologic features of the acetabulum.

Methods: Through the process of CT scanning, and edge recording of the CT image, we made use of CAD software and Unigraphics software to reconstruct the 40 normal acetabulum bones for the radius of acetabulum (R), minimum thickness of medial wall of acetabulum (L), depth of Harris fossa (D) and maximum opening rim width in cross-sectional plane (W).

Results: The average R was 30.