Charlotte A. Pratt

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Activity patterns were recorded from 51 motoneurons in the fifth lumbar ventral root of cats walking on a motorized treadmill at a range of speeds between 0.1 and 1.3 m/s. The muscle of destination of recorded motoneurons was identified by spike-triggered averaging of EMG recordings from each of the anterior thigh muscles. Forty-three motoneurons projected(More)
BACKGROUND Physical activity is important for weight control and good health; however, activity levels decline in the adolescent years, particularly in girls. DESIGN Group randomized controlled trial. SETTING/PARTICIPANTS Middle school girls with English-speaking skills and no conditions to prevent participation in physical activity in 36 schools in six(More)
Cat sartorius has two distinct anatomical portions, anterior (SA-a) and medial (SA-m). SA-a acts to extend the knee and also to flex the hip. SA-m acts to flex both the knee and the hip. The objective of this study was to investigate how a "single motoneuron pool" is used to control at least three separate functions mediated by the two anatomical portions(More)
BACKGROUND Research on the metabolic syndrome and its association with lifestyle behaviors in adolescents is important for identifying subgroups of youth at whom interventions should be targeted. OBJECTIVE To examine the relationship of metabolic syndrome with diet and physical activity in US adolescents. DESIGN A sample of 4,450 12- to 19-year-olds was(More)
BACKGROUND Providing after school activities is a community level approach for reducing the decline in physical activity of girls as they reach early adolescence. PURPOSE The purpose of this study was to examine psychosocial, environmental, and behavioral factors as potential mediators of after school physical activity in adolescent girls. METHODS We(More)
The cat hindlimb contains several long, biarticular strap muscles composed of parallel muscle fascicles that attach to short tendons. Three of these muscles--sartorius, tenuissimus, and semitendinosus--were studied by dissecting individual gold-stained fibers and determining the surface distribution of acetylcholinesterase-stained end-plate zones. In each(More)
Similarities between the muscle synergies associated with the flexion reflex and locomotion in reduced preparations have suggested that spinal circuits subserving these two motor tasks might share common interneurons. To test this hypothesis in functionally complex muscles, we studied the interaction between low-threshold cutaneous afferents and the(More)
Fine flexible wire microelectrodes chronically implanted in the fifth lumbar ventral root (L5 VR) of 17 cats rendered stable records of the natural discharge patterns of 164 individual axons during locomotion on a treadmill. Fifty-one out of 164 axons were identified as motoneurons projecting to the anterior thigh muscle group. For these axons, the(More)
OBJECTIVE This paper presents the reliability and validity of several diet-related psychosocial questionnaires. METHODS At baseline and 12 weeks follow-up, parents/caregivers of one hundred fifty 8- to 10-year-old African-American completed questionnaires on food preparation habits for their daughter, perceived home barriers to healthy eating, and fruit,(More)
Several cat hindlimb muscles that exhibit differential activation (activity that is restricted to a specific region of muscle) during natural movements were studied to determine the possible roles of 1) non-uniform distribution of histochemically-identified muscle fiber-types (semitendinosus, ST; tibialis anterior, TA) or 2) mechanical heterogeneity (biceps(More)