Biomedical subjects

Trevor J Allen

Publications and source records attributed to Trevor J Allen.

4 recordsLinked to original sources

PubMed2005

Abdominal muscle recruitment during a range of voluntary exercises.

Various exercises are used to retrain the abdominal muscles in the management of low back pain and other musculoskeletal disorders. However, few studies have directly investigated the activity of all the abdominal muscles or the recruitment of regions of the abdominal muscles during these manoeuvres. This study examined the activity of different regions of transversus abdominis (TrA), obliquus internus (OI) and externus abdominis (OE), and rectus abdominis (RA), and movement of the lumbar spine, pelvis and abdomen during inward movement of the lower abdominal wall, abdominal bracing, pelvic tilting, and inward movement of the lower and upper abdominal wall. Inward movement of the lower abdominal wall in supine produced greater activity of TrA compared to OI, OE and RA. During posterior pelvic tilting, middle OI was most active and with abdominal bracing, OE was predominantly recruited. Regions of TrA were recruited differentially and an inverse relationship between lumbopelvic motion and TrA electromyography (EMG) was found. This study indicates that inward movement of the lower abdominal wall in supine produces the most independent activity of TrA relative to the other abdominal muscles, recruitment varies between regions of TrA, and observation of abdominal and lumbopelvic motion may assist in evaluation of exercise performance.

Abdominal Muscles↗

PubMed2005

Investigation of transabdominal real-time ultrasound to visualise the muscles of the pelvic floor.

Clinical measurement of pelvic floor muscle activity commonly involves techniques that are both physically and psychologically invasive. This study investigated transabdominal application of ultrasound to measure pelvic floor muscle action. The specific aims were to establish the face validity of ultrasound measures of displacement of the posterior bladder wall as a reflection of pelvic floor muscle contraction, and the reliability of measurement between raters and between testing occasions. Non-pregnant adult female subjects aged 24 to 57 years were tested in lying with a 3.5 MHz 35 mm curved array ultrasound transducer over the lower abdomen. Posterior bladder wall displacement was observed in both sagittal and transverse planes. Digital vaginal palpation and transabdominal ultrasound were undertaken simultaneously during pelvic floor muscle contractions to confirm that pelvic floor contractions were performed correctly and to grade pelvic floor muscle strength. Displacement (mm) was measured using electronic calipers on the ultrasound monitor screen. In all subjects, a correct pelvic floor muscle contraction was confirmed on digital palpation, and consistent anterior and cephalic movement was observed on screen. Digital strength grading did not correlate with ultrasound measures in either transverse or sagittal planes (r = 0.21 and -0.13). Average intra-class correlation coefficients for within session inter-rater reliability ranged between 0.86 and 0.88 (95% CI 0.68 to 0.97), and for inter session intra-rater reliability between 0.81 and 0.89 (95% CI 0.51 to 0.96). Transabdominal application of diagnostic ultrasound is a personally non-invasive method for imaging and assessing pelvic floor muscle activity and is both valid and reliable.

Adult↗

PubMed2005

Damage to skeletal muscle from eccentric exercise.

Evidence is provided for a mechanical event as the first step in the process leading to muscle damage after a series of eccentric contractions. Aspects discussed include the decline in active tension, increase in passive tension, shift in length-tension relation, soreness, swelling, and disturbed proprioception.

Adaptation, Physiological↗

PubMedDate not supplied

Recovery of lower limb function following 6 weeks of non-weight bearing.

Skeletal muscle weakness and atrophy occur following an extended period of decreased use, including space flight and limb unloading. It is also likely that affected muscles will be susceptible to a re-loading injury when they begin return to earth or weight bearing. However, there is a paucity of literature evaluating the response of human unloaded muscle to exercise and return to activity. The purpose of this pilot study was to evaluate the soreness, function and strength response of muscle to re-loading in seven patients who were non-weight bearing for 6 weeks, compared to five healthy subjects. Function improved significantly over time for the patients but was still less than the healthy subjects over 12 weeks of physiotherapy. Concentric quadriceps muscle strength increased significantly over time for the patients. There was considerable variability in the patients' reports of muscle soreness but there were no significant changes over time or between groups.

Achilles Tendon↗