PubMed Health⌕ Search

Biomedical subjects

J A Whiteside

Publications and source records attributed to J A Whiteside.

At least 19 recordsLinked to original sources
PubMed1998

Biomechanics of windmill softball pitching with implications about injury mechanisms at the shoulder and elbow.

Underhand pitching has received minimal attention in the sports medicine literature. This may be due to the perception that, compared with overhead pitching, the underhand motion creates less stress on the arm, which results in fewer injuries. The purpose of this study was to calculate kinematic and kinetic parameters for the pitching motion used in fast pitch softball. Eight female fast pitch softball pitchers were recorded with a four-camera system (200 Hz). The results indicated that high forces and torques were experienced at the shoulder and elbow during the delivery phase. Peak compressive forces at the elbow and shoulder equal to 70-98% of body weight were produced. Shoulder extension and abduction torques equal to 9-10% of body weight x height were calculated. Elbow flexion torque was exerted to control elbow extension and initiate elbow flexion. The demand on the biceps labrum complex to simultaneously resist glenohumeral distraction and produce elbow flexion makes this structure susceptible to overuse injury.

Adult↗
PubMed1993

Common elbow problems in the athlete.

Because of the popularity of sports participation, sports physical therapists must recognize in the athlete the many clinical conditions that occur about the elbow. The purpose of this paper is to present the most common elbow problems that an athlete may encounter and to provide information to facilitate recognition of elbow pathology. This information is essential before initiating treatment. An attempt is made to include sprains, strains, neuropathies, dislocations, fractures, contusions, vascular insults, and skin problems in the distal humerus, elbow, and proximal forearm of both the immature and mature athlete. Comprehension of the mechanism of injury aids clinical evaluation and rehabilitation and enhances early return to activity.

Athletic Injuries↗
PubMed1988

Avulsion fractures involving the cruciate ligaments.

The evaluation of a child with an acute knee injury is difficult. The injury may be an avulsion fracture involving either of the cruciate ligaments; a common cause is a cycling accident. The amount of fragment displacement dictates the management. Minimal displacement can be treated with immobilization in flexion. Larger displacement requires internal fixation, which can be accomplished arthroscopically. Rehabilitation must be early and aggressive.

Bicycling↗
PubMed1987

The rapid hydrolysis and efficient absorption of triglycerides with octanoic acid in the 1 and 3 positions and long-chain fatty acid in the 2 position.

We describe rapid hydrolysis of triglycerides with medium-chain fatty acids in the 1 and 3 positions and a long-chain fatty acid in the 2 position. The triglycerides, 2-linoleoyl-1,3-dioctanoyl glycerol (8L8) and 2-oleoyl-1,3-dioctanoyl glycerol, hydrolyzed more rapidly than triglycerides comprising all long-chain fatty acids. The in vitro hydrolysis rate of 8L8 was similar to that of a medium-chain triglyceride of octanoic and decanoic acids in random positions. From intestinal recovery of 14C 45 min after injection into the isolated, irrigated loop of the small intestine of an anesthetized rat, the amount of 2-[1-14C]linoleoyl-1,3-dioctanoyl glycerol absorbed was greater than 2 1/2 times that of its long-chain analog, 2-[1-14C]linoleoyl-1,3-dioleoyl glycerol. These data support the ease of hydrolysis and absorption of 1,3-dioctanoyl triglycerides with long-chain fatty acids in the 2 position.

Animals↗
PubMed1987

Preparing allied health faculty to use and develop computer-assisted instruction.

Microcomputers can be powerful teaching tools if educators learn to develop effective computer-assisted instruction (CAI). This paper reports on an allied health faculty development project that incorporated hands-on workshops and guided individual instruction led by a specialist in the educational uses of microcomputers. Faculty participants gained basic computer literacy skills and learned to assess the salient characteristics of quality software. They also learned specialized skills for designing their own CAI packages. The positive change in participants' knowledge about and attitude toward microcomputers as instructional tools was measured both subjectively by the authors and by a participants' self-report questionnaire. This project can serve as a model for helping allied health educators become computer literate and gain the skills necessary to evaluate and author quality computer-assisted instruction.

Arkansas↗
PubMed1986

Reflex cardiovascular responses caused by stimulation of pulmonary C-fibers with capsaicin in dogs.

The purpose of these studies was to determine quantitatively the reflex cardiovascular responses to stimulation of the pulmonary C-fibers in dogs. We used a preparation in which the airway, pulmonary artery, and the pulmonary veins to the left lung were cannulated in situ. Ventilation and perfusion of the right lung maintained the animal in relatively normal homeostasis. Capsaicin, a decylenic acid amide of vanillylamine that selectively stimulates nerve endings of unmyelinated fibers (C-fibers), was injected into the left pulmonary artery in 5-ml boluses. Maximal reflex responses were obtained with concentrations as low as 0.8-1.6 X micrograms-1 X kg-1. Heart rate, hindlimb resistance, and left ventricular contractility were lowered transiently (the maximal responses showing declines of 40, 13, and 15.2%, respectively). As a result of these changes, combined with vasodilation in other resistance vessels, cardiac output fell 28% and blood pressure fell 35%. Interrupting the afferent neural pathway by severing the ipsilateral cervical vagus nerve eliminated these responses, confirming the distribution of their reflex origin. Although the role of these reflexes in homeostasis has not been decided, the results of this study suggest that the lungs of dogs, if appropriately stimulated, potentially can exert a major inhibitory influence on the neural regulation of cardiovascular function.

Afferent Pathways↗
PubMed1986

Women athletes with menstrual irregularity have increased musculoskeletal injuries.

We have performed a retrospective three-phase study to evaluate the effect of menstrual status upon musculoskeletal injuries in women athletes. Initially, we collected the menstrual and running histories of women participants in a regional 10-km footrace. In this study, 61% of the respondents to our questionnaire reported a continuous running program, and 39% reported an interruption of at least 3 months of their running program. The most common cause for interruption was injury. Those who had interrupted their running were more likely to have had irregular or absent menses and less likely to have been using oral contraceptives than the group of continuous runners. Secondly, we obtained information on the relationship between bone injury and menstrual status by reviewing the sports medicine records of 207 collegiate women athletes. We found that X-ray-documented fractures occurred in 9% of women athletes with regular menses and in 24% of women athletes with irregular or absent menses. Subsequently, we collected data from a larger population of more serious, but still recreational runners, participating in a national 10-km race. Each portion of this study has yielded similar results: those women who had been injured during their running program were more likely to have had absent or irregular menses, were less likely to have used oral contraceptives, and had been running for more years. We conclude that premenopausal women who have absent or irregular menses, while engaged in vigorous exercise programs, are at increased risk for musculoskeletal injury.

Adult↗
PubMed1976

Effects of exposure duration on part-whole perception in children.

Drawings of familiar objects arranged to suggest more general wholes (e.g., a beast made of pieces of fruit) were presented to 128 children aged 3-12 years, using 4 exposure durations. The ability to see both parts and wholes together improved with age, confirming earlier studies. In addition, the results suggest that limiting viewing time affects the ability to see both parts and wholes together (in a sequential, nonintegrated fashion) more in young children than in older children. The results further suggest that for younger children duration does not affect the ability to see parts and wholes in a hierarchical relationship. These results are interpreted as suggesting that at least 2 different processes mediate part-whole perception in children.

Age Factors↗
PubMed1976

Peripheral vision in children and adults.

Threshold luminance necessary to evoke an eye movement was evaluated as a function of age (6-21 years) and visual angle (6 degrees-42 degrees from the fovea). Results were comparable to those of static perimetry in older subjects but showed little narrowing of the visual field in younger children.

Adolescent↗
PubMedDate not supplied

Fractures and refractures in intercollegiate athletes. An eleven-year experience.

This report on fractures and refractures in intercollegiate athletes covers an 11-year period from the early Fall of 1968 through the Spring of 1979. Two hundred thirty-one fractures occurred in 219 athletes. Of these athletes, 185 were male and 34 were female. Fractures occurred in 18 sports. Of these 18, football, basketball, wrestling, and soccer led in number for Men's (M) teams, and gymnastics, lacrosse, and volleyball led for Ladies' (L) teams. (Because of this institution's early involvement with Title IX, and the strong position taken by our administration, our teams are designated Gentlemen (Men for short), which constitute the LIONS, and Ladies, which make up the LADY LIONS.) No fractures were noted in the other 11 intercollegiate teams of cheerleading (M and L), bowling (M and L), golf (M and L), fencing (L), rifle (coed), tennis (M and L), and volleyball (M). Boxing, ice hockey, rugby, soccer, and synchronized swimming are club sports at the Pennsylvania State University and are not included in this study. The most common of the 17 fracture sites were the finger, hand, face, foot, nose, and leg, regardless of sport or gender. Fourteen of fifteen refractures occurred in collision/contact sports, and essentially the same mechanical forces caused both fractures. In football most fractures occurred during highly successful seasons.

Adult↗