Joseph K-F Ng

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STUDY DESIGN Repeated measures for intratester reliability were performed. OBJECTIVES To investigate the intratester reliability of a new measurement technique that evaluates lumbar range of motion in three planes using a pelvic restraint device, and to examine the reliability of lumbar lordosis measurement by inclinometer technique. Preliminary normative(More)
The ability of surface electrodes to accurately detect the activity of a particular muscle relies not only on their being placed over the muscle but also on their position in relation to muscle fibre orientation. For optimal pick-up of electromyographic (EMG) signals, surface electrodes are best aligned in parallel with the fibre orientation of the(More)
BACKGROUND AND PURPOSE Muscle endurance is an important variable to measure in the assessment of back muscle function. This study investigated the electromyographic (EMG) activity and fatigue patterns of iliocostalis lumborum and multifidus muscles during a trunk holding test. SUBJECTS Sixteen male subjects (mean age = 24.2 years, SD = 4.2, range =(More)
PURPOSE Wavelet transform is a time-frequency analysis method that quantifies temporal changes of the frequency content of nonstationary signals without losing resolution in time or frequency. It may be used to analyze surface EMG (sEMG) signals under dynamic conditions. However, this method is difficult to apply clinically because it generates large(More)
OBJECTIVE AND DESIGN To investigate the reliability (within-day and between-days) of measurements of electromyographic (EMG) power spectral values in measurement of the fatigue rate of the back muscles. METHODS Twelve healthy male subjects were tested in the unsupported trunk holding position for 60 seconds. Two trials were performed on each of two(More)
Electromyographic (EMG) studies have shown that a large number of trunk muscles are recruited during axial rotation. The functional roles of these trunk muscles in axial rotation are multiple and have not been well investigated. In addition, there is no information on the coupling torque at different exertion levels during axial rotation. The aim of the(More)
PURPOSE The aims of the present study were to examine electromyographic (EMG) activity of six bilateral trunk muscles during maximal contraction in three cardinal planes and to determine the direction of contraction that gives maximal activation for each muscle, both for healthy subjects and back-pain patients. METHODS Twenty-eight healthy subjects and 15(More)
Back muscles are important to the stability of the lumbar spine. Muscle fiber composition may give some indication of the functional capacity of these muscles. This review explores the relationship between muscle fiber composition and functional capacity of back muscles. The reference values for the type and size of the muscle fibers found in the back(More)
OBJECTIVE The aim of the present study was to investigate the between-days reliability of electromyographic (EMG) measurement of 6 bilateral trunk muscles and also the torque output in 3 planes during isometric right and left axial rotation at different exertion levels. METHODS Ten healthy subjects performed isometric right and left axial rotation at 100,(More)
Back exercises addressing deep muscles with a prime stabilising role such as multifidus are important in the rehabilitation of patients with low back pain. Electromyography of erector spinae and multifidus of 18 healthy subjects was investigated during prone arch and two isometric back extension exercises; trunk holding and leg holding. When compared with(More)