Ronald W. Davis
Gale M. Gehlsen, Ronald W. Davis, and Rafael Bahamonde
The purpose of this study was to describe the intermittent velocity variation of wheelchair propulsion and to determine the relationship between selected wheelchair propulsive characteristics and peak velocity. The subjects were 11 (10 males and 1 female) members of the U.S. 1988 Paralympic Track and Field Team. Each subject’s personal racing chair was mounted on a Pro Roller. Intermittent velocity was ascertained by a tach-generator. A stationary 16-mm Locam camera was used to photograph the subject’s sagittal plane propulsive movements. A sonic digitizer was used to digitize three complete propulsive cycles for each subject. Paraplegic and quadriplegic subjects’ stroke frequency mean values were 2.27 and 1.80 Hz, respectively. Significant correlations between the Pro Roller’s computer-generated peak velocity values and hand-handrim positions were indicated. Handrim contact angles and trunk angles were approximately 30 to 40° forward of the same angles reported in the literature. Results indicate that a forward lean of the trunk may allow the athlete to increase the range of hand-handrim contact.
Michael S. Ferrara and Ronald W. Davis
Ronald W. Davis, Jerome E. Kotecki, Michael W. Harvey, and Amy Oliver
This study describes responsibilities and training needs of paraeducators in physical education. Paraeducators (n =138) employed in 34 midwestern schools received a 27-item questionnaire. Of the 138 paraeducators contacted, 76 responded, resulting in a 55.1% response rate. Only 16% of the total respondents (n = 76) reported receiving specific training in physical education; however, 68 (90%) indicated a willingness to be trained. Less than half (n = 29, 38%) indicated participating in physical education by escorting students, providing cues, and working individually with students. Fewer than eight (28%) of the physical education paraeducators assisted with assessments, shared IEP suggestions, or helped implement behavior modification programs. The most desired training areas included activity modifications, attributes of students with disabilities, and knowledge of motor development.
Andrew W. Subudhi, Scott L. Davis, Ronald W. Kipp, and E. Wayne Askew
The goal of this field study was to assess antioxidant status and markers of oxidative damage in elite alpine ski racers during routine training. Subjects included 12 members of the U.S. Men’s Alpine Ski Team attending a 10-day summer training camp. Blood draws were collected at rest and after exercise: (a) prior to training, (b) following 2 days of dry land training, and (c) after 4 days of on-snow skiing. Seven measures of antioxidant status were determined using colorimetric and HPLC methods (Trolox “equivalent antioxidant capacity, uric acid, α-tocopherol, β-tocopherol, total glutathione, cytosolic glutathione peroxidase, and superoxide dismutase). Oxidative stress was assessed using 2 markers of lipid peroxidation (malondialdehyde and lipid hydroperoxides) and 2 markers of protein oxidation (carbonylated total proteins and carbonylated hemoglobin). The results of this study suggest that antioxidant status of elite alpine skiers may decline over a period of intense training. However, elevations in markers of oxidative stress were not evident.
Sangwoo Lee, Ronald Davis, Lawrence W. Judge, Young-Hoo Kwon, Kihoon Han, Jemin Kim, Jaewoong Kim, and Jaehwa Kim
The purpose of this study was to investigate the relationships among release factors (speed, height, and angle) and distance thrown in Paralympic seated shot put. Fortyeight trials performed by 11 men and 5 women during the 2012 US Paralympic trials in track and field were analyzed. With both genders combined, release speed (r = .95, p < .01) and angle (r = .51, p < .01) showed significant correlations to distance thrown. Release speed (r = .94, p < .01) in men and all release factors (r = .60–.98, p < .02) in women showed significant correlations to distance. Release speed and angle were identified as important predictors of the distance, explaining over 89–96% of the variance in distance thrown. Unlike athletes without disability, seated shotputters exhibited significant positive speed–angle correlations (combined: r = .37, p < .01; women: r = .57, p = .03). Application of these results should address a focus in training on generating speed through the release point with a consistent release angle.
Brandon R. Rigby, Ronald W. Davis, Marco A. Avalos, Nicholas A. Levine, Kevin A. Becker, and David L. Nichols
The purpose of this study was to compare acute cardiometabolic responses to 3 modes of treadmill exercise in adults diagnosed with Parkinson’s disease (PD). Eight elderly adults with PD (67.9 ± 3.0 yr) completed 1 session each on a land, aquatic, and antigravity treadmill at 50% body weight. Participants walked from 1 to 3 mph in 0.5-mph increments at 0% grade for 5 min at each speed. Heart rate, energy expenditure, blood pressure, and rating of perceived exertion were measured at rest and during exercise. All variables except diastolic blood pressure increased with speed on all treadmills (p < .001). At all speeds except 1.5 mph, heart rate was higher on the land treadmill than the antigravity treadmill (p < .05). Exercising on an aquatic or antigravity treadmill elicits similar submaximal physiologic responses to exercise on a land treadmill in adults with PD.
Tim L.A. Doyle, Ronald W. Davis, Brendan Humphries, Eric L. Dugan, Bryon G. Horn, Jae Kun Shim, and Robert U. Newton
A number of researchers have long questioned systems used for classifying athletes with disabilities. Wheelchair basketball players have gained much attention from researchers. Despite this, no change to the NWBA classification system has been made since it was first adopted in 1984. This study investigated the NWBA classification system. At two summer basketball camps, 46 players were tested to assess player sprint performance and stratification under the NWBA medical classification system. The group consisted of Class 1, 2, and 3 players. Electronic timing gates were used to collect 20 meter sprint-times. Results indicate that Class 1 players were significantly slower compared to Class 2 and 3 players (p < .05) with no difference between Class 2 and 3. The results of this study support a change to this system.