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Biomedical subjects

J Sandover

Publications and source records attributed to J Sandover.

10 recordsLinked to original sources
PubMed1992

An improved method of stature measurement for quantitative determination of spinal loading. Application to sitting postures and whole body vibration.

A refined procedure for measuring stature is described; this provides a reproducibility error of 0.4 mm. The procedure accommodates the natural diurnal change in stature and permits estimation of the net stature change caused by a change in spinal loading. A series of measurements done with a cohort of 20 young and middle-aged persons showed that stature decrease was related linearly to the quasi-static load on the spine. The coefficient of proportionality between load and height loss was inversely proportional to the cross-sectional area of the lumbar discs. This method was used to investigate sitting postures and whole-body vibration to demonstrate the applicability of the procedure to quantify spinal strain (and, therefore, estimate comparative loading) in applied ergonomics. Sitting invariably led to an increase in stature, regardless of the type of chair used or the posture maintained. Whole-body vibration did not induce any loss of stature. Thus, this novel approach was able to enhance understanding of spinal behavior under different loading conditions.

Adult↗
PubMed1987

Back pain in Grand Prix drivers: a 'found' experiment.

The 'found' experiment uses a natural change in conditions to investigate the possible effects of those conditions. In this case, the natural change was reduction in stiffness of Grand Prix suspensions between 1982 and 1983. The effects of this change on back pain in drivers were investigated and it was found that both the incidence and severity of back pain decreased significantly. Of the various possible sources of back pain, only the ride changed over the same period. This suggests that mechanical shock and vibration are a significant cause of driving related back pain.

Journal Article↗
PubMed1983

Dynamic loading as a possible source of low-back disorders.

Although the epidemiologic evidence is not convincing, a number of studies indicate that those exposed to dynamic loads may have increased risk to low-back disorders. A review of the available evidence suggests that chronic low-back pain relates to disc degeneration and that this in turn may be accelerated by mechanical failure in the region of the end-plate and subchondral bone or in the annulus. Two hypotheses are proposed to relate fatigue induced failure of vertebral tissues to disc degeneration. The extent of dynamic stresses on the vertebral motion segment arising from transport are investigated, and the results indicate that fatigue induced failure is a distinct possibility. The implications of these suggestions for environmental health protection are briefly discussed.

Back Pain↗
PubMed1979

A standard on human response to vibration--one of a new breed?

Human response to vibration is used as an example for consideration of the requirements of standards in the human factors field. It is suggested that standards relating to people may be concerned primarily with the design of equipment for optimum satisfaction of users, and that this demands a different approach to standards if they are to be effective. It is argued that a clear distinction should be made between standards intended to protect people from harmful conditions, standards intended to minimise the risk of people being harmed, and standards intended to give advice and information. In the case of human response to vibration it is suggested that standards should relate to agreed methods of measurement and assessment, limitations to preserve health, limitations to be applied in specific situations in order to prevent the risk of accidents, together with a data base for designers to work from.

Journal Article↗
PubMed1978

Modelling human responses to vibration.

Biodynamic measurements of human response to vibration may be nonlinear as a result of active control of the response, complex body movements, or tissue characteristics. Experiments using a random Gz stimulus were designed to explore the extent of these nonlinearities under normal conditions. The input transfer function was found to exhibit near-linearity, but transmission measures suffered from errors arising from complex body movements. The technique developed was found to be valuable for investigation of the variables affecting human response, and examples are given of the effects of body restraint and the relationship between intraabdominal pressure and input acceleration. It is argued that improved techniques and careful consideration of variables lead to a greater acceptance of the biodynamic approach.

Biomechanical Phenomena↗
PubMedDate not supplied

The damaging punch.

The mechanical properties of a boxing punch have been determined using several techniques. The results are consistent with the medical consequences of boxing discussed in the report of the Board of Science and Education Working Party on boxing. Data were gathered from a world ranked British professional heavyweight, Frank Bruno, as he punched an instrumented, padded target mass suspended as a ballistic pendulum. Within 0.1 s of the start the punch had travelled 0.49 m and attained a velocity on impact of 8.9 m/s. The peak force on impact of 4096N (0.4 ton), attained within 14 ms of contact, represents a blow to the human head of up to 6320N (0.63 ton). The transmitted impulse generated an acceleration of 520 m/s2 (53 g) in the target head. For comparison an equivalent blow would be delivered by a padded wooden mallet with a mass of 6 kg (13 lbs) if swung at 20 mph.

Athletic Injuries↗