Changes in the length and three-dimensional orientation of muscle fascicles and aponeuroses with passive length changes in human gastrocnemius muscles.

The mechanisms by which skeletal muscles lengthen and shorten are potentially complex. When the relaxed human gastrocnemius muscle is at its shortest in vivo lengths it falls slack (i.e. it does not exert any passive tension). It has been hypothesised that when the muscle is passively lengthened, slack is progressively taken up, first in some muscle fascicles then in others. Two-dimensional imaging methods suggest that, once the slack is taken up, changes in muscle length are mediated primarily by changes in the lengths of the tendinous components of the muscle. The aims of this study were to test the hypothesis that there is progressive engagement of relaxed muscle fascicles, and to quantify changes in the length and three-dimensional orientation of muscle fascicles and tendinous structures during passive changes in muscle length. Ultrasound imaging was used to determine the location, in an ultrasound image plane, of the proximal and distal ends of muscle fascicles at 14 sites in the human gastrocnemius muscle as the ankle was rotated passively through its full range. A three-dimensional motion analysis system recorded the location and orientation of the ultrasound image plane and the leg. These data were used to generate dynamic three-dimensional reconstructions of the architecture of the muscle fascicles and aponeuroses. There was considerable variability in the measured muscle lengths at which the slack was taken up in individual muscle fascicles. However, that variability was not much greater than the error associated with the measurement procedure. An analysis of these data which took into account the possible correlations between errors showed that, contrary to our earlier hypothesis, muscle fascicles are not progressively engaged during passive lengthening of the human gastrocnemius. Instead, the slack is taken up nearly simultaneously in all muscle fascicles. Once the muscle is lengthened sufficiently to take up the slack, about half of the subsequent increase in muscle length is due to elongation of the tendinous structures and half is due to elongation of muscle fascicles, at least over the range of muscle-tendon lengths that was investigated (up to ∼60 or 70% of the range of in vivo lengths). Changes in the alignment of muscle fascicles and flattening of aponeuroses contribute little to the total change in muscle length.

How much equipment is prescribed for people with spinal cord injury in Australia, do they use it and are they satisfied 1 year later?

BACKGROUND AND PURPOSE: The purpose of this study was to determine the amount and type of equipment prescribed to aid mobility and self-care for patients with spinal cord injuries (SCI) in Australia and to determine how frequently the equipment is used 1 year later and whether patients are satisfied with it. METHODS: A consecutive series of 61 patients admitted for rehabilitation to two Sydney SCI units were recruited. All mobility and self-care equipment worth more than $AU50 prescribed by therapists before patients' discharge was recorded. This included wheelchairs, commodes, shower chairs, hoists, electric beds, pressure-relieving cushions, bed mattresses, slideboards, walking aids, orthoses, electrical stimulation systems and other pieces of notable exercise equipment. Patients were interviewed 1 year later and asked about each piece of equipment they had been prescribed. Specifically, they were asked about how frequently they had used each piece of equipment and whether they were satisfied with it. Data were analysed using descriptive statistics. RESULTS: Three hundred and fourteen pieces of equipment, including 68 wheelchairs, were prescribed for the 61 patients. Most of the equipment (226/314) was used more than 20 times in the 2 months preceding the 1-year review. Most patients were satisfied or highly satisfied with the majority of equipment prescribed, although patients were very dissatisfied or only partly dissatisfied with 18/314 pieces of equipment. DISCUSSION: Patients were generally satisfied with the equipment they were prescribed. There was a small amount of equipment prescribed that was not used 1 year later or with which patients were dissatisfied.

Incidence and predictors of contracture after spinal cord injury--a prospective cohort study.

STUDY DESIGN: Prospective cohort study. OBJECTIVES: To determine incidence of contracture and develop prediction models to identify patients susceptible to contracture after spinal cord injury. SETTING: Two Sydney spinal cord injury units. METHODS: A total of 92 consecutive patients with acute spinal cord injury were assessed within 35 days of injury and 1 year later. Incidence of contracture at 1 year was measured in all major appendicular joints by categorizing range of motion on a 4-point scale (0-no contracture to 3-severe contracture), and in the wrist, elbow, hip and ankle by measuring range of motion at standardized torque. Multivariate models were developed to predict contracture at 1 year using age, neurological status, spasticity, pain and limb fracture recorded at the time of injury. RESULTS: At 1 year, 66% of participants developed at least one contracture (defined as ≥1 point deterioration on the 4-point scale). Incidence of contracture at each joint was: shoulder 43%, elbow and forearm 33%, wrist and hand 41%, hip 32%, knee 11% and ankle 40%. Incidence of contracture determined by standardized torque measures of range (defined as loss of ≥10 degrees) was: elbow 27%, wrist 26%, hip 23% and ankle 25%. Prediction models were statistically significant but lacked sufficient predictive accuracy to be clinically useful (R(2)≤31%). CONCLUSION: The incidence of contracture in major joints 1 year after spinal cord injury ranges from 11-43%. The ankle, wrist and shoulder are most commonly affected. It is difficult to accurately predict those susceptible to contracture soon after injury.