Validation of an adapted MRI pulse sequence for quantification of fatty infiltration in muscle.

Purpose: The long-term goal of our research is to develop a patient-specific biomechanical model of the supraspinatus muscle and tendon for analyzing the effects of fatty infiltration and pennation angle changes. One input of the model will be the amount and distribution of fat within the muscle. Therefore, the objective of this project was to adapt and validate a novel magnetic resonance imaging pulse sequence for quantifying the extent of fatty infiltration for the supraspinatus muscle.

An integer programming model for distal humerus fracture fixation planning.

Objective: To demonstrate the feasibility of an integer programming model to assist in pre-operative planning for open reduction and internal fixation of a distal humerus fracture.

Materials And Methods: We describe an integer programming model based on the objective of maximizing the reward for screws placed while satisfying the requirements for sound internal fixation. The model maximizes the number of bicortical screws placed while avoiding screw collision and favoring screws of greater length that cross multiple fracture planes.

A stochastic analysis of glenoid inclination angle and superior migration of the humeral head.

Background: Superior glenoid inclination, which is a relatively upward facing of the glenoid in the plane of the scapula, has been associated with rotator cuff pathology. Increased glenoid inclination may cause superior humeral head migration, which can cause impingement of the supraspinatus tendon. The purpose of this study was to test the hypothesis that inclination angle affects the probability of superior humeral head migration.

The reproducibility of a kinematically-derived axis of the knee versus digitized anatomical landmarks using a knee navigation system.

Component position is critical to longevity of knee arthroplasties. Femoral component rotation is typically referenced from the transepicondylar axis (TEA), the anterior-posterior (AP) axis or the posterior condylar axis. Other studies have shown high variability in locating the TEA while proposing digitization of other landmarks such as the AP axis as a less-variable reference.

Evaluation of three methods for determining EMG-muscle force parameter estimates for the shoulder muscles.

Background: Accurate prediction of in vivo muscle forces is essential for relevant analyses of musculoskeletal biomechanics. The purpose of this study was to evaluate three methods for predicting muscle forces of the shoulder by comparing calculated muscle parameters, which relate electromyographic activity to muscle forces.

Methods: Thirteen subjects performed sub-maximal, isometric contractions consisting of six actions about the shoulder and two actions about the elbow.