BACKGROUND The presence of multiple allergies has been correlated with worse outcomes for patients undergoing hip and knee arthroplasty, but the effect of allergies has not yet been elucidated with respect to shoulder arthroplasty. PURPOSE/HYPOTHESIS The purpose of this study is to identify any discrepancies in shoulder arthroplasty outcomes with respect to reported drug allergies. We hypothe...

BACKGROUND CONTEXT Accurate anatomical inputs for biomechanical models are necessary for valid estimates of internal loading. The magnitude of the moment arm of the lumbar erector muscle group is known to vary as a function of such variables as gender. Anatomical evidence indicates that the moment arms decrease during torso flexion. However, moment arm estimates in biomechanical models that acc...

This study investigates the altered thoracohumeral kinematics when forearm rotation is restricted while performing five activities requiring pronation and supination. Two splints simulated both a fixed-supinated or fixed-neutral forearm in six healthy subjects; the three-dimensional coupled relationship among motion about the forearm, elbow, and shoulder were analyzed. In using a screwdriver, t...

Longer spinal fusions have been shown to result in improved deformity correction; however, loss of normal flexibility in the fusion area should not be ignored. Current consensus was to achieve a shorter fusion in primary surgery, with the goal of preserving as much of the distal motion segment as possible. However, the correlation between the length of fusion and functional outcome remains cont...

BACKGROUND CONTEXT Occipital condyle screws appear to be a novel technique that demands biomechanical consideration. It has the potential to achieve fixation anterior to the axis of rotation while offering a point of fixation in line with the C1/C2 screws. PURPOSE To compare the segmental stability and range of motion (ROM) of standard occipitocervical (OC) screw/rod and plate constructs vers...

The purpose of this study was to describe the firing pattern of 11 hip and knee muscles during running. Thirty recreational runners volunteered to run at 3 different paces with indwelling electromyographic electrodes while being filmed at 100 frames per second. Results demonstrated that medial and lateral vasti muscles acted together for knee extension during terminal swing and loading response...

Joint contractures decrease the patient's ability to walk, but usually other parts of the body compensate the affected joint contractures. When we restore the gait performance in paraplegic patients by means of functional electrical stimulation, however, we cannot expect complications of compensation. A computer simulation was done to clarify how the contractures affect the gait pattern when no...

In this chapter, a series of biomechanics simulations were conducted to reconstruct a specific movement – spine flexion/extension in sagittal plane of a subject. The motion capture was used to collect the kinematics information of the subject. These motions were used to drive a customized musculoskeletal model in OpenSim. Additionally, the muscle actuation forces and joint reactions were comput...

Aim: To investigate the correlation between the craniocervical posture measurements obtained by the biophotogrammetric and cephalometric analysis. Methods: 80 women aged between 19 and 35 years were evaluated by the cephalometric and biophotogrammetric methods. The cephalometric variables were: CVA (position of flexion/extension of the head) CPL (forward head posture) CVT/EVT ratio (cervical co...