The WISTAH hand study: a prospective cohort study of distal upper extremity musculoskeletal disorders.

Background: Few prospective cohort studies of distal upper extremity musculoskeletal disorders have been performed. Past studies have provided somewhat conflicting evidence for occupational risk factors and have largely reported data without adjustments for many personal and psychosocial factors.

Methods/design: A multi-center prospective cohort study was incepted to quantify risk factors for distal upper extremity musculoskeletal disorders and potentially develop improved methods for analyzing jobs.

Measuring sensory nerve action potential electrical power.

Sensory nerve action potential (SNAP) amplitudes are frequently examined for evidence of axonal loss. Because digital nerves have parallel fibers, and parallel voltages do not add, SNAP amplitude may not accurately reflect axonal loss. In contrast, electrical power can be measured for digital nerves, and is additive.

Biomechanics of the double rocker sole shoe: gait kinematics and kinetics.

The use of footwear with contoured soles is common in treatment and care of patients with diabetes; these rocker sole shoes are designed to alleviate loading in key areas on the plantar surface of the foot, reducing pressure in key areas and alleviating pain, and potential soft tissue damage. While investigations of pressure changes have been conducted, no quantitative study to date has addressed the three-dimensional (3D) kinematic and kinetic changes that result from using these shoes. Forty subjects were tested wearing both unmodified and double rocker sole shoes, and the resulting motion patterns were compared to assess change caused by the rocker sole.

Nerve conduction topography in geriatric hand assessment.

Motor nerve conduction is a noninvasive clinical test used to diagnose nerve problems such as carpal tunnel syndrome or peripheral neuropathy. Current techniques use a single-site recording over a superficial muscle. This traditional approach does not account for the electrical contributions from the other muscles innervated by the nerve being stimulated, which need to be considered with thumb carpometacarpal (CMC) degenerative joint disease (DJD) because these electrical contributions may change the anatomic relationship of the thenar muscles.

Effects of the toe-only rocker on gait kinematics and kinetics in able-bodied persons.

Rocker sole shoes are commonly prescribed to diabetic patients with insensate feet. Recent passage of the therapeutic shoe bill has drawn an increased focus on prescription of rehabilitative footwear. The purpose of this work is to investigate the dynamics of lower extremity joints (hip, knee, and ankle) with the application of a toe-only rocker sole shoe under controlled laboratory conditions.

Effect of rocker soles on plantar pressures.

Objective: To examine the effect of different types of rocker soles on plantar pressures.

Design: In-shoe plantar pressures were measured in subjects without deformity with baseline shoes and 3 types of rockers: toe-only, negative heel, and double.

Setting: Medical college.

Quantitative electromyography.

Quantitative EMG is an MUAP analysis technique providing objective information on the NEE. The concept and techniques are not new; however, with the advancement of computer technology, quantitative EMG is now more easily performed. The study requires solid knowledge of basic neurophysiology and access to the appropriate instrument to provide smooth technique and accurate interpretation.

Development of a quantitative reflex hammer for measurement of tendon stretch reflex.

Quantification of tendon stretch reflex requires precise measurement of the tapping force of a reflex hammer. A quantitative reflex (QR) hammer consisting of two cut rubber pieces from a generic rubber reflex hammer and a uniaxial force transducer was constructed. Finite element stress analyses were conducted to estimate the natural frequency characteristics of the hammer and to find the stress distributions during the impact.

Effect of reference electrode position on the compound muscle action potential (CMAP) onset latency.

Compound muscle action potential (CMAP) onset latency is interpreted to reflect the arrival time at the muscle of impulses in the fastest-conducting motor nerve fiber. However, we have observed that the position of the reference or indifferent electrode (E2) affects CMAP onset latency. Motor nerve conduction studies (NCS) of the median, ulnar, and deep ulnar motor (DUM) nerves on 20 normal hands were performed using both traditional bipolar and experimental monopolar (referenced to the contralateral hand) montages.

Analysis of postural control synergies during quiet standing in healthy children and children with cerebral palsy.

Objective: To estimate the contribution of body transverse rotation using weighted differential center of pressure signals during quiet standing in healthy children and in children with cerebral palsy.

Design: Body sway was indirectly measured through center of pressure data, which was calculated using dual force platforms.

Background: Assessment of postural control synergies using center of pressure data provides a unique method for center of mass data analysis in characterizing complex balance sway.