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This paper provides an overview of forward dynamic neuromusculoskeletal modeling. The aim of such models is to estimate or predict muscle forces, joint moments, and/or joint kinematics from neural signals. This is a four-step process. In the first step, muscle activation dynamics govern the transformation from the neural signal to a measure of muscle(More)
The external knee adduction moment during walking and stair climbing has a characteristic double hump pattern. The magnitude of the adduction moment is associated with the development and progression of medial compartment knee osteoarthritis (OA). There is an inverse relationship between the magnitude of the second peak adduction moment and foot progression(More)
The overall goal of this work was to determine an optimal surface-tracking marker set for tracking motion of the tibia during natural cadence walking. Eleven different marker sets were evaluated. The marker sets differed in the location they were attached to the shank, the method used to attach the marker sets to the segment and the physical characteristics(More)
STUDY DESIGN Cross-sectional experimental laboratory study. OBJECTIVES To investigate the relationships between hip strength and hip kinematics, and between arch structure and knee kinematics during prolonged treadmill running in runners with and without patellofemoral pain syndrome (PFPS). BACKGROUND Hip weakness can lead to excessive femoral motions(More)
Ultrasonography was used to measure pennation angle and electromyography (EMG) to record muscle activity of the human tibialis anterior (TA), lateral gastrocnemius (LG), medial gastrocnemius (MG), and soleus (SOL) muscles during graded isometric ankle plantar and dorsiflexion contractions done on a Biodex dynamometer. Data from 8 male and 8 female subjects(More)
BACKGROUND Whether an Achilles tendon rupture is treated surgically or not, complications such as muscle weakness, decrease in heel-rise height, and gait abnormalities persist after injury. PURPOSE The purpose of this study was to evaluate if side-to-side differences in maximal heel-rise height can be explained by differences in Achilles tendon length. (More)
PURPOSE The study of angular kinetic data provides important information regarding muscle function and may lend insight into the etiology of overuse injuries common to runners. These injuries are often due to deviations in the secondary planes of motion. However, little is known about the angular kinetics in these planes leaving no reference for comparison.(More)
BACKGROUND Isolated gastrocnemius contracture (IGC), which limits ankle dorsiflexion with full knee extension, can affect function and quality of life. Gastrocnemius recession is a treatment option for IGC when conservative treatment fails. The goal of this study was to assess range of motion, function, and plantarflexion strength pre- and 3-months(More)
An EMG-driven virtual arm is being developed in our laboratories for the purposes of studying neuromuscular control of arm movements. The virtual arm incorporates the major muscles spanning the elbow joint and is used to estimate tension developed by individual muscles based on recorded electromyograms (EMGs). It is able to estimate joint moments and the(More)
Nonlinearities have been observed in the isometric EMG-force relationship. However, these are generally not included when using EMG-driven Hill-type muscle models that account for muscle activation dynamics. In this paper, we present a formulation for a one-parameter transformation model (i.e., A-model) that accounts for the type of physiological(More)