Reliability of the Cobb angle index derived by traditional and computer assisted methods.

The reliability of the traditional Cobb angle index, which at present exhibits a wide range of reported values, was determined in this study and amounted to a within subject error of +/-4.3 degrees and a between subject error of +/-4.9 degrees. An attempt to pinpoint the source of this variability by investigating the influence of choice of end vertebrae proved inconclusive. The reliability of a computer assisted Cobb angle index, developed to improve measurement accuracy, was also examined and an estimated within subject error of +/-1.5 degrees and a between subject error of +/-1.6 degrees obtained. A comparison of the traditional and computer assisted methods indicates a high correlation between the Cobb angle derived using the two methods when measuring like curves and an improved reliability obtained by the computer method. Such an improvement is worth implementing clinically but of course the availability of a computer and digitizer and a little extra time for an operator to input the X-ray coordinates may be a barrier to its general use.

The dynamic mechanical response characteristics of spinal cord tissue: a preliminary report.

In the absence of an adequate description of the response of spinal cord to dynamic insult, work is in hand to determine the dynamic characteristics of canine spinal cord tissue. In-vitro experimentation is described. A vibration technique using a low amplitude (0.5 mm), variable frequency (1--40 Hz) forcing frequency is used to describe the resonant property of the tissue in a supporting environment. The canine spinal cord is demonstrated to respond as a non-linear, soft, viscoelastic element suceptible in the frequency range 14--22 Hz.

An improved orthopaedic stirrup.

A single RPH universal stirrup covers the many types of traction needed in orthopaedic practice. It reduces the torque load on the Steinmann pin, thereby diminishing the rate of loosening of the pin in the bone. From our experience with the stirrup at the Royal Perth Hospital, savings in ward costs can be achieved by shortening the time in hospital and reducing the need for antibiotic cover, by decreasing maintenance costs and by reducing the size of the appliance stock kept to cover the range of tractions used in orthopaedic practice.

A device for producing experimental fractures.

A device is reported for the production of transverse fractures of canine tibiae by a three-point bending technique. With strain-gauged load arms, the device enables simultaneous measurement of the bend strength of the intact bone. Results from a series of 14 dogs confirm the reproducibility of this technique.

Musculoskeletal effects of an electrical stimulation induced cycling programme in the spinal injured.

Twelve patients were involved in a 3 month stimulation induced cycling programme at the Royal Perth Rehabilitation Hospital. A number of the patients were less than 1 year post injury, all except one had an incomplete injury, and most were receiving physiotherapy. All patients who completed the programme increased their time of cycling and, in all but one case, the exercise load, indicative of a local training effect. Significant improvements were found in voluntary isometric strength, stimulated isometric strength and stimulated isometric endurance of the quadriceps, muscle grading of the quadriceps and biceps femoris and the cross-sectional areas of the quadriceps and total thigh muscle. No change was found in voluntary isokinetic strength of the quadriceps. All patients with incomplete injuries reported improvements in the activities of daily living (ADL) after the programme. Bone mineral density (BMD) was examined in two patients, one less than 1 year post injury, and one greater than 4 years post injury. The programme of cycling did not restore BMD in the latter patient. However, while the former patient still displayed a reduced BMD after the programme, it is unknown whether this loss of bone was retarded. This needs further investigation. This study demonstrates the effectiveness of a combined physiotherapy/cycling programme in the rehabilitation of people with spinal injuries. To be successful this type of programme has to be incorporated into the rehabilitation process, as has been done at the Sir George Bedbrook Spinal Unit.

A clinical exercise system for paraplegics using functional electrical stimulation.

A low cost clinical exercise system was developed for the spinal cord injured, based on a bicycle ergometer and electrical stimulation. A pilot project was conducted, using the system, to examine the effects of stimulation induced cycling in long term paraplegics. The project comprised 2 phases of exercise, a strengthening phase involving a 12 week programme of electrical stimulation to the quadriceps and hamstrings and a 12 week cycling phase. Physiological, morphological and biochemical parameters were measured for each subject, at the beginning of the programme and following each phase. Results showed that a programme of stimulation induced lower limb exercise increased the exercise tolerance of all patients, as determined by a progressive increase in exercise time, cycling rate and exercise load. The enhanced exercise tolerance was a result of increases in local muscle strength and endurance. Increases in thigh muscle area and joint range of motion were recorded and all incomplete subjects reported an improvement in functional capabilities and general wellbeing.