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Biomedical subjects

D C Reid

Publications and source records attributed to D C Reid.

35 records · Page 2Linked to original sources
PubMed1989

The influence of high-velocity circuit resistance training on VO2max and cardiac output.

In order to investigate the influence of high-velocity circuit resistance training on maximal aerobic power, maximal stroke volume and cardiac output, and blood lactate removal during recovery, 16 habitually active males were blocked on initial VO2max into either training or control groups. The training group completed two (weeks 1 and 2) or three (weeks 3-6) circuits of 10 variable-resistance hydraulic exercise stations at an exercise: relief ratio of 1:2 on alternate days over six weeks. Angular velocities of movement were maintained at approximately 3.1 rad.s-1. Following training, the VO2max was increased (p less than .01) from 4.32 to 4.68 1.min-1. Maximal stroke volume was increased (p less than .05) from 120 to 129 mL and heart rate response to an absolute submaximal exercise load was decreased (p less than .05) from 153 to 146 beats.min-1. As well, enhanced (p less than .01) removal of lactate from the blood was observed during recovery from exhausting exercise. No changes were observed for control subjects. These results indicate that positive alterations in aerobic and cardiovascular function may be achieved consequent to high-velocity circuit resistance training.

Cardiac Output↗
PubMed1988

The nonoperative treatment of burst fractures of the thoracolumbar junction.

Treatment of thoracolumbar spine burst fracture with a neurologically intact patient is controversial, with advocates of operative and nonoperative approaches. Of 404 patients in a prospective spinal trauma study, 21 had burst fractures, were neurologically intact, and had greater than 1-year followup. This group was analyzed to evaluate treatment with early mobilization using a thoracolumbar total contact orthosis. The average time in a brace was 6 months. Two patients had pulmonary embolus treated successfully with anticoagulants. No patient required subsequent surgery for increasing kyphosis or neurologic deficit. Change in K angle at followup was 4.6 degrees (+/- 5.7) and change in anterior vertebral height was 6.1 degrees (+/- 10). All patients had a satisfactory pain score and most individuals returned to full employment. It is concluded that it is not necessary to routinely treat patients operatively with burst fractures if they fulfill the following criteria: 1) neurologically intact; 2) kyphosis angle less than 35 degrees; 3) other injuries do not preclude the use of a total contact orthosis; and 4) the patient is capable of understanding and cooperating with the treatment regime. These criteria are irrespective of the CT findings of posterior vertebral retropulsion and spinal canal narrowing.

Adolescent↗
PubMed1988

Prevention of hip and knee injuries in ballet dancers.

Hip problems form about 10% (7.0 to 14.2%) of most published series of ballet injuries. The abnormally large range of external rotation needed for a perfect turnout is primarily due to soft tissue adaptation, more readily achieved in the young dancer. Insufficient range of motion at the hip throws considerable stress on the other lower limb segments. The snapping hip syndrome is common (43.8% of hip problems), with about one-third associated with pain. A tight iliotibial band may contribute to this, and balanced flexibility requires special attention to abductor stretching. The external clicking hip must be distinguished from the internal clicking hip, which is associated with the joint and psoas tendon. Stress fractures of the hip are easily overlooked and, if undetected, they may progress to a complete fracture. Knee problems account for 14.0 to 20% of complaints, and over 50% of these are peri- or retropatellar problems. This includes synovial plica, medial chondromalacia, lateral patella facet syndrome, subluxing patella and the fat pad syndrome. Specific diagnosis leads to specific treatment and the best chance of cure. Mild hyperextension of the knee may be aesthetically desirable, but excessive range leads to symptoms in the posterior capsule and poor control. Young dancers with a tendency to very lax joint structures should be identified early and protected from overstretching. In the author's series, meniscal lesions did not appear to be as big a problem as reported elsewhere in the literature. Ballerinas appear to have less leg strength than other groups of athletes, having only 77% of the weight-predicted norms. The introduction of strength training for male and female dancers may reduce injuries and improve balance, but it requires an intensive educational programme to dispense with the many myths. There are several references to the development of early arthritis but, while relatively common in the foot, symptomatic arthrosis in ballet dancers' hips and knees is not more prevalent than in the general population. The young age at which serious dance training begins, the long and rigorous hours of practice, the thin ballet slipper, dancing en pointe and unusual dietary regimens may all contribute to injury patterns in varying degrees.

Dancing↗
PubMed1988

Off-road recreational motor vehicle accidents: hospitalization and deaths.

There is increasing concern over the unregulated use of recreational off-road motor vehicles. A review of 207 patients admitted to a tertiary care hospital over a 5-year period, as well as deaths due to use of recreational vehicles, elicited the following information. Recreational accidents predominantly involved men in their mid-twenties. Children younger than 16 years were more frequently involved in all-terrain vehicle (ATV) or dirt-bike accidents and constituted more than one-third of the total. There was a ninefold increase in ATV accidents over the study period, so that by 1985 ATVs were the primary cause of off-road injuries (52%). The musculoskeletal system was most frequently injured (66%) followed by the head and face (25%). There was permanent disability in 10.6%, and 33% of the recreational deaths were in children younger than 16 years. The inherent instability of ATVs was confirmed by the finding that in 60% of accidents the vehicle had rolled or flipped. Stricter licensing requirements should be implemented, and public education is required to draw attention to the danger of these vehicles, particularly to children. There is a need for proper safety equipment and driver training. The issue of vehicle design must also be addressed by the industries concerned.

Accidents↗
PubMed1987

Etiology and clinical course of missed spine fractures.

A prospective study was designed to document course and outcome. Two hundred fifty-three patients with 274 spinal injuries were reviewed at the time of injury and discharge from hospital, as well as at 1, 2, and 5 years postinjury. Thirty-eight of these patients were identified who had been misdiagnosed at the initial assessment. Fracture location, cause of injury, neurologic deficit, and delay in diagnosis were all documented: 22.9% of cervical injuries, and 4.9% of the thoracolumbar injuries had a delayed diagnosis ranging from less than 1 day to 36 days. The causes of delayed diagnosis were: 1) failure to take X-rays, 2) fractures missed on X-ray, and 3) failure of patients to seek medical attention. Associated factors such as intoxication of the patient, multiple injuries, level of consciousness, or two levels of spinal injury contributed to the delayed diagnosis of these injuries. Certain "at-risk" populations for missed spinal injuries have been identified. In spite of delays in diagnosis, progression of an established neurologic deficit did not appear to occur in our study. However, the development of secondary deficits was significant in the delayed diagnosis group.

Accidents, Traffic↗
PubMed1987

A biomechanical evaluation of sorbothane.

Sorbothane (I.E.M. Orthopaedics, Aurora, Ohio), a viscoelastic polymer, has been developed for orthopedic application, but there has been little substantiation of the claim that it is capable of absorbing 95% of the impact energy in foot strike. Sorbothane has been used extensively in orthotic insoles in order to minimize the symptoms of joint degeneration, prosthesis loosening, and various soft tissue disorders resulting from the impact generated at foot strike during walking and running. The viscoelastic properties of Sorbothane were investigated by Durometer tests at various temperatures as well as compression tests of thin discs of material with different degrees of lateral constraints and varying rates of loading. Sorbothane has the characteristics of a viscoelastic solid with a relaxation time of two seconds. The effects of lateral constraint were significant, indicating that the properties of this material will change when bonded to other substances in the production of insoles. The final transmitted stress over the duration of foot strike would not be reduced by more than 10%, which may have some therapeutic implication, but not of the magnitude suggested by other authors.

Athletic Injuries↗
PubMed1986

A comparison of muscle fiber characteristics at different levels of the vertebral column in the rhesus monkey.

The vertebral muscle fiber characteristics of adult female rhesus monkeys have been examined. Muscle samples were obtained from precisely defined superficial and deep sites on both sides of the vertebral column. In particular, samples were collected from three different levels of the column and the muscle fiber characteristics from all these different sites were compared. It is clear that in the rhesus monkey at least, muscle fiber characteristics are dependent on the vertebral level although not necessarily on the side of the vertebral column.

Animals↗
PubMed1976

Role of selected muscles of respiration as influenced by posture and tidal volume.

Studies of the activity of accessory respiratory muscles were conducted in 30 normal subjects (15 male and 15 female subjects, age 5 to 62 years). Electromyograms were recorded over the right serratus anterior muscle and the adjacent sixthe intercostal space, and the results were correlated with tidal volume. Phasic respiratory activity in the serratus anterior muscle was detected in every subject but was markedly affected by the prevailing posture and level of ventilation (appearing at mean tidal volumes equivalent to 60.5 percent of vital capacity when subjects were standing relaxed, and equivalent to 35.2 percent of vital capacity when subjects were seated, leaning forward with elbows supported). The activity was predominantly inspiratory in timing but in some subjects extended into early expiration. No significant differences were noted in subjects of different ages, sex, height, or weight. Similar results were recorded from the inspiratory intercostal muscle. On the basis of these findings, we conclude that, contrary to reports, the serratus anterior muscle should be classified as an accessory muscle of respiration, at least at increased levels of ventilation, and that its activity is most pronounced in postures that place the muscles' origin in an advantageous position for moving the ribs.

Adolescent↗
PubMedDate not supplied

Lower extremity flexibility patterns in classical ballet dancers and their correlation to lateral hip and knee injuries.

Knee and hip problems account for up to 40% of injuries in classical ballet. Despite apparent flexibility, many dancers appeared to have tight iliotibial bands that contributed to lower limb problems. Thirty senior female ballet dancers were contrasted with thirty age-matched active volunteers for hip and knee range of motion, and the information derived was correlated with their orthopaedic medical histories. Dancers spent a reasonable period of time warming up, but it was usually with an unbalanced routine that emphasized hip abduction and external rotation to the exclusion of adduction work. This was reflected in the significantly lower range of passive hip adduction and internal rotation compared to the controls. Furthermore, the older and more experienced the dancer, the more this trend was exaggerated. This unbalanced flexibility may play a role in the production of lateral knee pain (30% of the dancers) and anterior hip pain (33% of the dancers). It is suggested that more attention should be given to a balanced stretching regimen as part of the dancers' warmup in an effort to reduce the frequency of some of the chronic hip and knee complaints.

Adolescent↗
PubMedDate not supplied

Anterior compartment pressures in cross-country skiers. A comparison of classic and skating skis.

This paper compares the pressure changes in the anterior compartment of the leg when cross-country skiing using the skating method on either skating skis or classic skis. Intracompartmental pressures of the right leg were recorded from the tibialis anterior muscle of 10 subjects at rest and 15 seconds after 10 to 12 minutes of cross-country skiing on a designated course. All subjects completed two trials on different days. In one trial, subjects used skating skis and for the other trial, classic skis were used for the skating technique. Although the average pressure increase was higher for the classic ski trials than for the skating ski trials, the difference was not significant. This finding indicates that cross-country skiers who skate on a classic ski as opposed to a shorter skating ski do not experience a significantly greater increase in their anterior compartment pressure. Thus, it appears that the type of ski used is not the most significant factor contributing to chronic compartment syndrome.

Adult↗
PubMedDate not supplied

Shoulder pain in wheelchair athletes. The role of muscle imbalance.

Shoulder rotator cuff impingement syndrome is a common and disabling problem for the wheelchair athlete. In this study we investigated the role of shoulder strength imbalance as a factor for the development of this syndrome. Nineteen paraplegic male athletes underwent clinical and isokinetic examination of both shoulders with peak torque values measured in abduction, adduction, and internal and external rotation. Twenty athletic, able-bodied men without shoulder problems were tested as controls. Ten (26%) of the paraplegic athletes had rotator cuff impingement syndrome. The results of the isokinetic testing demonstrated that 1) the paraplegics' shoulders were stronger than the controls in all directions (P < 0.05); 2) the strength ratio of abduction: adduction was higher for paraplegic athletes (P < 0.05); 3) paraplegics' shoulders with rotator cuff impingement syndrome were weaker in adduction and external and internal rotation than the paraplegic athletes without impingement syndrome (P < 0.05); and 4) paraplegics' shoulders with rotator cuff impingement syndrome had higher abduction:adduction and abduction:internal rotation strength ratios than the shoulders of paraplegics without impingement syndrome (P < 0.05). We concluded that shoulder muscle imbalance, with comparative weakness of the humeral head depressors (rotators and adductors), may be a factor in the development and perpetuation of rotator cuff impingement syndrome in wheelchair athletes.

Adult↗