Biomedical subjects

K D Coutts

Publications and source records attributed to K D Coutts.

30 records · Page 2Linked to original sources

PubMed1984

Relation between oxygen uptake & power output during wheelchair ergometry in tetraplegics and paraplegics.

Twenty-one disabled subjects, who use a wheelchair as a normal means of locomotion, completed a continuous, increasing workrate test to subjective exhaustion on a wheelchair ergometer. The subjects were classified into tetraplegic (n = 8), high lesion paraplegic (n = 6), and low lesion paraplegic (n = 7) groups, and linear regression analyses to predict oxygen uptake (l/min) from power output (watts) were carried out for each group. Tetraplegics exhibited a non-significant correlation (r = .21) between power output and oxygen uptake. This was possibly due to their low maximal attainable oxygen uptake and limited range for these variables. A significant relationship was noted in both paraplegic groups (r = .93), and analysis indicated a lack of significant difference (p = .88) in the regression equations between the two groups. The high and low lesion paraplegic group measures were combined to produce a single regression equation given by VO2 (l/min) = .108 + .0267 X Power (watts).

Disability Evaluation↗

PubMed1983

Maximal exercise responses of tetraplegics and paraplegics.

Eight tetraplegic and 13 paraplegic subjects performed a continuous progressive loading exercise test to exhaustion on a wheelchair ergometer. Their cardiorespiratory responses at maximal O2 uptake were analyzed after initially grouping subjects according to the international system for classification of wheelchair athletes. Analysis of variance provided a basis for regrouping the subjects into tetraplegic (T), high-lesion paraplegic (HLP), and low-lesion paraplegic (LLP) groups and indicated significant differences (P less than 0.05) in maximal power output (24, 47, and 80 W) and O2 uptake (0.97, 1.62, and 2.42 l/min) for T, HLP, and LLP, respectively. T had a significantly lower maximal heart rate (110) compared with the paraplegic values (175 and 190), whereas the HLP, in contrast to the LLP, had a lower maximum ventilation (66 vs. 101 l/min) and a lower O2 pulse (9.3 vs. 12.7 ml/beat). The ventilatory equivalent for O2 was similar in all groups to values for able-bodied subjects in maximal arm crank ergometry, however, suggesting a lack of any respiratory limit to maximal O2 delivery. No differences were noted in respiratory exchange ratio or net efficiency between the groups. In addition to limitations of functional muscle mass, the data suggested that the reduced cardiac capacity of T and HLP may also be linked to their lower maximal exercise capacity and O2 uptake.

Adult↗

PubMed1982

Kinetic differences of two volleyball jumping techniques.

The vertical component of ground reaction force-time curves for two styles of jumping used in preparation for a spike in volleyball were analyzed in a group of 86 players. The two styles consisted of a hop approach where the player lands simultaneously on both feet prior to take-off, and a step-close (SC) approach where one foot is placed in its take-off position followed by the trailing foot being placed adjacent to it before take-off. A total of 15 variables from the curves for each style were compared using analysis of variance techniques. The hop jump was characterized as having a higher velocity at the end of the approach resulting in a faster and larger absorption impulse. This produced a faster positive impulse with a higher average force, peak force, and acceleration which is consistent with a greater storage and utilization of elastic energy of the muscles. No significant differences were found in the time and average force for the final unweighting phase of the impulse, and no differences were note in take-off velocities. Thus, the hop jump resulted in decreasing the time of the impulse by increasing the average and peak forces during the impulse with no apparent effect on jump height.

Biomechanical Phenomena↗

PubMed1981