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Biomedical subjects

D A Skelton

Publications and source records attributed to D A Skelton.

9 recordsLinked to original sources
PubMed2003

Exercise and injury prevention in older people.

This review aims to provide the reader with up to date evidence in relation to the role of exercise in the reduction of risk factors and the prevention of falls and injuries. Falls and injury may lead to a spiral of inactivity and decline that take older people close to or below the critical "thresholds" of performance necessary for everyday activities. Yet, low strength and power, poor balance, poor gait and functional ability, and fear of falling are all risk factors for falls modifiable with tailored exercise. Although the evidence on types, amounts and specificity of exercise to prevent falls is not complete, recommendations have been published that have been effective, either as an exercise stand-alone intervention or with exercise as part of a multifactorial intervention. It is clear that the target population must be at risk or already fallers, they must be "not too fit" and "not too frail". Supervised home-based exercise programs may be effective in those aged over 80 because they fall more frequently, injure more easily, and recover more slowly. In younger, community-dwelling, fallers multifactorial group interventions including targeting of balance, strength, power, gait, endurance, flexibility, co-ordination and reaction may be more effective. There are, however, research questions that still need answering - whether there are certain types of exercise harmful in certain subgroups of older people, what is the ideal intensity, frequency and duration of exercise for different subgroups of older people (primary and secondary prevention) and the relative value of the different components of fitness to prevention of falls and injuries. This review highlights the necessity of tailored, specific balance and strength exercise in the multidisciplinary prevention of falls and injuries.

Accidental Falls↗
PubMed1999

Hormone replacement therapy increases isometric muscle strength of adductor pollicis in post-menopausal women.

A randomized open trial of hormone replacement therapy was used to assess changes in adductor pollicis muscle strength during 6-12 months of treatment with Prempak C 0.625(R) in comparison with an untreated control group. Muscle strength (maximal voluntary force; MVF), muscle cross-sectional area and bone mineral density were measured. Women entering the trial had oestrogen levels below 150 pmol.l-1, confirming their post-menopausal hormonal status. In the treated group, MVF increased by 12.4+/-1.0% (mean+/-S.E.M.) of initial MVF over the duration of treatment, while it declined slightly (2.9+/-0.9%) in the control group. This increase in strength could not be explained by an increase in muscle bulk, there being no significant increase in cross-sectional area during the study. Those subjects who were weakest at enrolment showed the greatest increases in muscle strength after treatment. Bone mineral density in total hip, Ward's triangle and total spine increased in the treated group, in agreement with previous studies. There was no correlation between the individual increases in bone mineral density and those in MVF.

Analysis of Variance↗
PubMed1995

Effects of resistance training on strength, power, and selected functional abilities of women aged 75 and older.

OBJECTIVE: To determine the effects of 12 weeks of progressive resistance strength training on the isometric strength, explosive power, and selected functional abilities of healthy women aged 75 and over. DESIGN: Subjects were matched for age and habitual physical activity and then randomly assigned into either a control or an exercise group. SETTING: The Muscle Function Laboratory, Royal Free Hospital School of Medicine, London. PARTICIPANTS: Fifty-two healthy women were recruited through local and national newspapers. Five dropped out before and seven (4 exercisers and 3 controls) during the study. Pre- and posttraining measurements were obtained from 20 exercisers (median age 79.5, range 76 to 93 years) and 20 controls (median age 79.5, range 75 to 90 years). INTERVENTIONS: Training comprised one supervised session (1 hour) at the Medical School and two unsupervised home sessions (supported by an exercise tape and booklet) per week for 12 weeks. The training stimulus was three sets of four to eight repetitions of each exercise, using rice bags (1-1.5 kg) or elastic tubing for resistance. The exercises were intended specifically to strengthen the muscles considered relevant for the functional tasks, but were not to mimic the functional measurements. No intervention was prescribed for the controls. MEASUREMENTS: Pre- and posttraining measurements were made for isometric knee extensor strength (IKES), isometric elbow flexor strength (IEFS), handgrip strength (HGS), leg extensor power (LEP), and anthropometric indices (Body impedance analysis, arm muscle circumference, and body weight). Functional ability tests were chair rise, kneel rise, rise from lying on the floor, 118-m self-paced corridor walk, stair climbing, functional reach, stepping up, stepping down, and lifting weights onto a shelf. Pre- and posttraining comparisons were made using analysis of variance or analysis of covariance (using weight as a covariate) for normally distributed continuous data and one-sided Fishers exact test (2 x 2 table) for discontinuous data. RESULTS: Improvements in IKES (mean change 27%, P = .03), IEFS (22%, P = .05), HGS (4%, P = .05), LEP/kg (18%, P = .05) were associated with training, but the improvement in LEP (18%, P = .11) did not reach statistical significance. There was an association between training and a reduction in normal pace kneel rise time (median change 21%, P = .02) and a small improvement in step up height (median 5%, P = .005). The other functional tests did not improve. CONCLUSIONS: Progressive resistance exercise can produce substantial increases in muscle strength and in power standardized for body weight in healthy, very old women. However, isolated increases in strength and LEP/kg may confer only limited functional benefit in healthy, independent, very old women.

Activities of Daily Living↗
PubMed1994

Applied physiology of strength and power in old age.

The loss of strength and power in old age has important implications for health. Even with healthy elderly people, cross-sectional comparisons imply a loss of strength at some 1.5% per year and of power at some 3.5% per year (averaged across the age range 65 to 84). On the other hand, healthy, very elderly people are at least as responsive to strength-training as younger adults. It is important to establish whether elderly people derive functional benefit from training-induced improvements in strength and whether laboratory measurements of strength and power might be used to identify those elderly people most at risk of losing important, everyday functional abilities.

Activities of Daily Living↗
PubMed1994

Exercise studies with elderly volunteers.

The practicalities of conducting exercise studies with elderly and very elderly people have not been well described. In order to help others plan and perform such studies we describe our experience of recruiting volunteers, applying selection criteria, measuring strength, power, cardiorespiratory responses, and potentially related functional abilities. Exclusion criteria are offered, for safety and to characterize subjects as free of disease which might alter their exercise performance. International agreement on these, or similar, criteria would be valuable. The budget must be adequate for prolonged recruitment before a study and for the liberal use of taxis during it. With healthy subjects in their seventies, the coefficients of variation (CV) for repeated measurements of strength and power were: handgrip 3%, isometric knee extension 6%, isometric elbow flexion 6%, and lower limb extensor power 9%. CV for isometric knee extension by healthy subjects in their eighties was 4%. Treadmill ergometry is more time-consuming than with younger subjects. During progressive treadmill tests, the heart rate interpolated to oxygen consumptions of 10 and 15 ml.kg-1.min-1 had CV = 4% and 7%, respectively.

Aged↗
PubMed1994

Strength, power and related functional ability of healthy people aged 65-89 years.

This cross-sectional study was designed to examine the effects of healthy ageing on muscle strength, power, and potentially related functional ability. Subjects were recruited through local and national newspapers and inclusion was based on strict health criteria, by questionnaire. Isometric knee extensor, isometric elbow flexor and handgrip strength, leg extensor power, timed rise from a low chair, lifting a weighted bag on to a surface, and stepping unaided on to boxes of different heights were measured in 50 men and 50 women, evenly distributed over the age range 65-89 years. The differences in isometric strength and leg extensor power over the age range were equivalent to 'losses' of 1-2% per annum and approximately 3 1/2% per annum, respectively. The decline of explosive power was faster than the decline of knee extensor strength in men (p = 0.0001), but not significantly so in women (p = 0.08). Power standardized for body weight influenced chair rise time and step height. Isometric knee extensor strength standardized for body weight influenced chair rise time.

Aged↗
PubMedDate not supplied

Muscle function of women aged 65-89 years meeting two sets of health criteria.

This study compared the isometric strength, leg extensor power, and some potentially related functional abilities of elderly women selected for exercise studies according to two sets of readily applicable exclusion criteria. The health status criteria ("healthy" and "medically stable") differed principally in respect to duration of freedom from diagnosed or symptomatic disease, medication taken and Body Mass Index. Fifty "healthy" women and fifty "medically stable" women, aged 65 to 89 and evenly distributed over the age range, were recruited through local and national newspapers. There was no significant difference between the two health groups in strength or power. However, the women in the "medically stable" group were heavier and had more difficulty in rising from a chair. The strength of the relationships between strength, power and kneel rise time were very dependent on body weight for the "medically stable" women but not for the "healthy" women. The health criteria used to classify elderly subjects must be clearly specified so that there may be easier interpretation of results from future studies. This is especially true in studies where body weight might be important.

Age Factors↗