Knee power is an important parameter in understanding medial knee joint load in knee osteoarthritis.

Objective: To determine the extent to which knee extensor strength and power explain variance in knee adduction moment (KAM) peak and impulse in clinical knee osteoarthritis (OA).

Methods: Fifty-three adults (mean ± SD age 61.6 ± 6.

Relationship of intermuscular fat volume in the thigh with knee extensor strength and physical performance in women at risk of or with knee osteoarthritis.

Objective: To determine the extent to which thigh intermuscular fat (IMF) and quadriceps muscle (QM) volumes explained variance in knee extensor strength and physical performance in women with radiographic knee osteoarthritis (ROA) and without.

Methods: Baseline data from 125 women (age ≥50 years) in the Osteoarthritis Initiative study, with or at risk of knee ROA were included. Knee extensor strength was measured using a fixed force transducer, normalized to body mass (N/kg).

Sensory nerve action potentials and sensory perception in women with arthritis of the hand.

Background: Arthritis of the hand can limit a person's ability to perform daily activities. Whether or not sensory deficits contribute to the disability in this population remains unknown. The primary purpose of this study was to determine if women with osteoarthritis (OA) or rheumatoid arthritis (RA) of the hand have sensory impairments.

Muscle activation during hand dexterity tasks in women with hand osteoarthritis and control subjects.

Study Design: Descriptive cross-sectional study.

Introduction: Hand osteoarthritis (OA) is a condition that results in hand pain and disability. It is important to understand how muscle function impairments contribute to impaired dexterity.

Comparison of pQCT-based measures of radial bone geometry and apparent trabecular bone structure using manufacturer and in-house-developed algorithms.

Peripheral quantitative computed tomography (pQCT) provides noninvasive densitometric and morphometric measures of total, trabecular, and cortical bone compartments. Skeletal changes over time can be determined by repeated measurements. Image thickness of 2.

Bayesian aggregation versus majority vote in the characterization of non-specific arm pain based on quantitative needle electromyography.

Background: Methods for the calculation and application of quantitative electromyographic (EMG) statistics for the characterization of EMG data detected from forearm muscles of individuals with and without pain associated with repetitive strain injury are presented.

Methods: A classification procedure using a multi-stage application of Bayesian inference is presented that characterizes a set of motor unit potentials acquired using needle electromyography. The utility of this technique in characterizing EMG data obtained from both normal individuals and those presenting with symptoms of "non-specific arm pain" is explored and validated.

Differences in EMG spike shape between individuals with and without non-specific arm pain.

The purpose of this study was to determine whether spike shape analysis of surface electromyographic (SEMG) activity is a useful tool to study muscle disorders. This study investigated SEMG spike shape parameters at low levels of contraction and changes in SEMG spike shape across different levels of isometric wrist extension contractions in individuals with non-specific arm pain (NSAP), asymptomatic subjects deemed at-risk for repetitive strain injury, and asymptomatic control subjects. Twenty-two asymptomatic control subjects, 8 at-risk subjects, and 16 subjects with NSAP participated.

Motor unit potential morphology differences in individuals with non-specific arm pain and lateral epicondylitis.

Background: The pathophysiology of non-specific arm pain (NSAP) is unclear and the diagnosis is made by excluding other specific upper limb pathologies, such as lateral epicondylitis or cervical radiculopathy. The purpose of this study was to determine: (i) if the quantitative parameters related to motor unit potential morphology and/or motor unit firing patterns derived from electromyographic (EMG) signals detected from an affected muscle of patients with NSAP are different from those detected in the same muscle of individuals with lateral epicondylitis (LE) and/or control subjects and (ii) if the quantitative EMG parameters suggest that the underlying pathophysiology in NSAP is either myopathic or neuropathic in nature.

Methods: Sixteen subjects with NSAP, 11 subjects with LE, eight subjects deemed to be at-risk for developing a repetitive strain injury, and 37 control subjects participated.

Reliability of quantitative EMG analysis of the extensor carpi radialis muscle.

This study investigated the within-subject, intra- and inter-operator reliability of quantitative electromyographic (EMG) analysis using decomposition-based quantitative electromyography (DQEMG). Needle and surface-detected EMG signals were collected during low-level isometric contractions of the extensor carpi radialis (ECR) muscle. DQEMG was used to extract needle-detected motor unit potential (MUP) trains and surface-detected MUPs (SMUPs) associated with each train.

Physiological characteristics of motor units in the brachioradialis muscle across fatiguing low-level isometric contractions.

The purpose of this study was to determine (i) if decomposition-based quantitative electromyography (DQEMG) could detect changes in motor unit potential (MUP) morphology and motor unit (MU) firing pattern statistics associated with muscle fatigue, (ii) if any detected changes are correlated with surface electromyographic (SEMG) signs of fatigue, and (iii) if significant fatigue-dependent changes are repeatable within individuals. Mean MU firing rates and the morphology of MUPs detected using needle and surface electrodes during constant-torque isometric contractions held until exhaustion were investigated in the brachioradialis (BR) muscle in 10 healthy volunteers (mean age=28.6 yr, SD+/-3.

Adaptations during familiarization to resistive exercise.

This study focused on adaptations during familiarization to resistive exercise. It was also determined if familiarization requires one or more sessions. Twenty-six sedentary, college-aged females were matched and randomly assigned to one of two groups.

Reliability of the biceps brachii M-wave.

Background: The peak-to-peak (P-P) amplitude of the maximum M-wave and the area of the negative phase of the curve are important measures that serve as methodological controls in H-reflex studies, motor unit number estimation (MUNE) procedures, and normalization factors for voluntary electromyographic (EMG) activity. These methodologies assume, with little evidence, that M-wave variability is minimal. This study therefore examined the intraclass reliability of these measures for the biceps brachii.