Biomedical subjects

I S McClay

Publications and source records attributed to I S McClay.

4 recordsLinked to original sources

PubMed2001

A radiographic analysis of the relationship between the size and shape of the intercondylar notch and anterior cruciate ligament injury.

Notch-view radiographs were obtained from 108 persons with anterior cruciate ligament (ACL) injuries (55 women, 53 men) and 186 with intact ACL (94 women, 92 men). Notch width, femur width, and notch width index were determined from each of the 294 radiographs. The notch was also categorized as either A-shaped or non-A-shaped. Intrarater and interrater reliability ranged from 0.82 to 0.99 for notch width and femur width, respectively. Reliability within and between raters for the classification of notch shape ranged from 0.80 to 1.0. Notch width was significantly influenced by a 10 degree change in knee angle when repeated radiographs were taken. Femur width was not affected by knee angle across this range. Analysis revealed a higher proportion of A-shaped notches among women than men. However, notch shape was not related to injury status. Results showed a smaller notch width and notch width index in ACL-injured patients regardless of notch shape or gender. A-shaped notches were smaller than non-A-shaped notches regardless of injury status or gender. Both notch width and notch width index were found to be significant indicators of ACL injury. Knowledge of the shape of the notch added no useful information in differentiating patients based on injury status. Thus, regardless of gender, individuals who possess smaller notch dimensions appear to be at greater risk of injury than individuals with larger notches.

Adolescent↗

PubMed2001

Arch structure and injury patterns in runners.

OBJECTIVE: The purpose of this study was to determine if high-arched and low-arched runners exhibit different injury patterns. DESIGN: Non-randomized, two-group injury survey. BACKGROUND: Running-related injuries are thought to be related, in part, to lower extremity structure. High-arched and low-arched runners with their different bony architecture may exhibit very different lower extremity mechanics and, consequently, different injury patterns. It was hypothesized that high-arched runners will exhibit a greater incidence of lateral injuries, skeletal injuries and knee injuries while low-arched runners will show a greater incidence of medial injuries, soft tissue injuries and foot injuries. METHODS: Twenty high-arched and 20 low-arched runners were included in this study. Running-related injuries were recorded and divided into injury patterns of medial/lateral, bony/soft tissue and knee/foot and ankle for both high-arched and low-arched runners. A chi(2) analysis was then employed in an attempt to associate injury patterns with arch structure. RESULTS: High-arched runners reported a greater incidence of ankle injuries, bony injuries and lateral injuries. Low-arched runners exhibited more knee injuries, soft tissue injuries and medial injuries. CONCLUSIONS: Based on these results, high and low arch structure is associated with different injury patterns in runners. Relevance. Different injury patterns are present in individuals with extreme high arches when compared to those with extremely low arches. These relationships may lead to improved treatment and intervention strategies for runners based on their predisposing foot structure.

Adult↗

PubMed2000

Measurements used to characterize the foot and the medial longitudinal arch: reliability and validity.

BACKGROUND AND PURPOSE: Abnormality in the structure of the medial longitudinal arch of the foot is commonly thought to be a predisposing factor to injury. The purpose of this investigation was to compare the reliability and validity of several measurements used to characterize various aspects of the foot, including the medial longitudinal arch. SUBJECTS: One hundred two feet (both feet of 51 subjects) were measured to establish a reference database. From this group, a subset of 20 feet (both feet of 10 subjects) was used to determine intertester and intratester reliability. Radiographs of a further subset of 10 feet (right feet of 10 subjects) were used to determine validity. METHODS: Five foot measurements were taken in 2 stance conditions: 10% of weight bearing and 90% of weight bearing. RESULTS: Intraclass correlation coefficients (ICCs) for intertester and intratester measurements were between.480 and.995. The most reliable method of characterizing arch type in 10% of weight bearing between testers was dividing navicular height by foot length in 10% of weight bearing. However, this measure yielded highly unreliable measurements in 90% of weight bearing. The most valid measurements were navicular height divided by truncated foot length, navicular height divided by foot length in 10% of weight bearing, and navicular height divided by foot length in 90% of weight bearing. Dorsum height at 50% of foot length divided by truncated foot length showed relatively high intertester reliability (ICC=.811 in 10% of weight bearing, ICC=.848 in 90% of weight bearing) and validity (ICC=.844 in 10% of weight bearing, ICC=.851 in 90% of weight bearing). CONCLUSION AND DISCUSSION: These data suggest that, of the measures tested, the most reliable and valid method of clinically assessing arch height across 10% and 90% of weight bearing was dividing the dorsum height at 50% of foot length by truncated foot length.

Adult↗

PubMed1986

Effects of side slope on wheelchair performance.

Compensation for the downhill turning moment of a wheelchair on a 2-degree side slope results in retarding force approximately equal to the rolling drag of a wheelchair on a level surface. The total drag force on the wheelchair while transversing a sloping surface is, therefore, roughly double the rolling drag. In contrast, the net energy cost of propulsion on this side slope is only 30 percent greater than for a level surface. Side slope propulsion is managed by "dragging" the uphill rim while pushing the downhill rim. Although this results in increased mechanical efficiency through greater use of a smaller muscle mass, it is more difficult and tiring for the wheelchair user.

Humans↗