Biomedical subjects

C Handford

Publications and source records attributed to C Handford.

4 recordsLinked to original sources

PubMed2001

Information--movement coupling: implications for the organization of research and practice during acquisition of self-paced extrinsic timing skills.

Information--movement coupling is a fundamental concept, integral to theorizing on the coordination of goal-directed activity in ecological psychology. In this paper, we examine the implications of this concept for the design of experimental research and the organization of practice during the acquisition of movement coordination in sport tasks. The task vehicle for our analysis is interceptive actions, in particular self-paced extrinsic timing tasks exemplified by serving in sports such as volleyball. Recent research highlighting the relevance of information--movement coupling for the process of practice in sport is discussed. We conclude that information--movement coupling represents an important principle for the structural organization of research and practice in self-paced extrinsic timing tasks and that further work is required to verify its significance across a range of sport movements.

Female↗

PubMed1997

Skill acquisition in sport: some applications of an evolving practice ecology.

This paper builds on recent theoretical concerns regarding traditional conceptualizations of the skill acquisition process. The implications for the process of practice in sport contexts are explored with reference to the information-processing approach to motor behaviour and the newer ecological paradigm. Issues are raised with current principles of practice based on traditional theoretical ideas. A practice strategy that gives greater weight to the guided exploration of the practice workspace jointly defined by the properties of the individual's subsystems, the specific task and the environment is advocated. Such a constraints-led perspective supersedes previous distinctions between rudimentary and voluntary skills. Sports scientists, coaches, teachers and movement rehabilitation therapists are invited to review current practices in the light of recent theoretical advances from the ecological perspective.

Adaptation, Physiological↗

PubMed1994

The natural physical alternative to cognitive theories of motor behaviour: an invitation for interdisciplinary research in sports science?

This review examines the viability of the natural physical alternative to traditional cognitive modelling of the sport performer. It is concluded that the natural physical perspective offers an attractive framework for the study of movement control and co-ordination in sport, but, at present, does not seem capable of superseding cognitive explanations. As a consequence of the nature of the questions they are asking, natural physical theorists offer a significant avenue for interdisciplinary research in sports science. Significant differences in the philosophy underpinning both theoretical views are acknowledged, but growing support for an integrated approach to motor control is highlighted. A major task for sports scientists may be to verify empirically the nature of an integrated model of the sport performer.

Humans↗

PubMed1993

Distance-dependent interactions between basal, cyclic AMP, and thyroid hormone response elements in the rat growth hormone promoter.

Developmental stage- and tissue-specific expression of the rat growth hormone (rGH) gene is conferred by DNA sequences within 237 base pairs of the transcription start site. Although binding of a number of transcription factors including Pit-1, Sp1, GHF3, and thyroid hormone receptor (T3R) stimulates rGH expression, several studies have suggested that interactions between these factors are important in determining cell specificity and responsiveness to extracellular signals. We have directly tested this hypothesis by creating a set of nested insertional mutations at two positions in the rGH promoter. Sequences were inserted at either position -148, separating GHF-3 and T3R binding sites from the downstream Pit-1 and Sp 1 binding sites, or at -51, separating the above elements from the TATA box. All insertions were made in the context of the rGH gene -237/+8 5'-flanking DNA, linked to a chloramphenicol acetyltransferase reporter gene and tested for activity by transient transfection in GC pituitary tumor cells. Insertions at both -148 and -51 caused sharp distance-dependent reductions in serum-stimulated expression such that insertions of 23 base pairs at -51 or 44 base pairs at -148 were sufficient to isolate the effects of sequences upstream of the insertion point. Insertions at -148 reduced T3 responsiveness severalfold but had little or no effect on stimulation by forskolin, whereas insertions at -51 reduced both T3 and forskolin responsiveness. Our results are consistent with the hypothesis that expression and regulation of the rGH gene is dependent on short-range protein-protein interactions, which are more critically dependent on spacing than the relative orientation of the transcription factor binding sites.

Animals↗