Biomechanics of the heel-raise exercise

The purpose of this investigation was to determine whether increases in internal (muscular) demand would be proportional to increases in the external demand during heel-raise exercise. Seven male (mean age 74.9 +/- 4.8 years) and 9 female (mean age 74.4 +/- 5.1 years) older adults performed both double-leg heel raises and single-leg heel raises under 3 loading conditions (no external resistance and +5% and +10% of each participant's body weight). Kinematic and kinetic dependent variables were calculated using standard inverse-dynamics techniques. The results suggest that although the single-heel raise led to increases in peak net joint moments, power, and mechanical-energy expenditure (MEE), it did so at the expense of range of motion and angular velocity. In addition, increasing the external resistance by 5% of participants' body weight did not elicit significant changes in either the power or the MEE of the ankle joint. These effects should be considered when prescribing these exercises to older adults.     

Studying social change with survey data: Examples from Louis Harris surveys

The recent publication of a volume that identifies almost 14 000 repeated questions from Louis Harris surveys should greatly facilitate the use of survey data for the study of social change. Four problems that accompany trend analyses with survey data are discussed in this paper with special attention to Harris data. They involve sample composition, question context, question wording, and short term versus long term change.     

Contract curve or implicit contract: Which will a union choose?

While much has been written about implicit and efficient (contract curve) contracts, little has been written about which contract a union will choose. This study examines how a democratic union chooses between these contracts. Under most conditions, unions reject an efficient contract and are more likely to choose an implicit contract, but a type of contract new to the economic literature could predominate over either.     

Concordance of Carcinogenic Response between Rodent Species: Potency Dependence and Potential Underestimation

The use of average qualitative concordance between two bioassay endpoints is considered, with emphasis directed at agreement between rats and mice from results of long-term carcinogenicity studies. It is noted that concordance varies as a function of the underlying potency or toxicity of the chemicals over which the averaging is performed. Thus, the averaging process dilutes large observed concordances from potent chemicals, and possibly inflates lower observed concordances from weakly active chemicals. Stratification over some measure of potency is suggested as a method for taking these effects into account. Statistical simulations of concordance analyses limited to low-potency ranges are employed to examine the concordance measure in greater detail. It is seen that at low potencies, observed concordance is consistently underestimated, reaching maximum levels of only about 80%.     

The timing of motherhood: The challenge to social workers

The timing of the first birth has become a critical issue, to be addressed by the social work profession. This paper suggests that women who have timed the birth of their first child at two different stages in adulthood have responded to the challenges of motherhood in divergent ways. In order to work as effectively as possible with mothers and children, social workers need to understand these differences related to the timing of motherhood.Dr. Walter is an Assistant Professor of Social Work at Widener University and is in private practice.     

Management commitment to safety and health in residential construction: HomeSafe spending trends 1991-1999

The support of good management is fundamental to the success of any safety and health program. Residential construction is a high-risk industry requiring significant commitment by management to impact day-to-day safety and health challenges. Investigators have evaluated management practices and spending trends in a cohort of 228 residential homebuilders in the Denver metro area of Colorado. Findings suggest that companies significantly increased dollars allocated to support safety and health practices between 1991 and 1999. In addition, the HomeSafe Pilot Program has positively impacted financial commitments of partner companies. Resource allocations were significantly greater for specific expense categories when comparing pre to post HomeSafe intervention. This paper presents data on the use of written safety and health programs, safety committees, and workers compensation premium cost containment certification, as well as allocations to safety incentive programs (SIP), personal protective equipment (PPE), other safety equipment (OSE), and safety training (ST).     

The Abuse of Deinstitutionalised Persons with Mental Handicaps

A decade or more ago there were a number of Government reports published of inquiries into the ill-treatment of patients in mental hospitals. Now that fewer people with mental handicaps are going into hospitals and others are leaving them to be integrated into the community will they be any better treated by those around them? The situation is briefly reviewed and a solution proposed to the problems uncovered, but the main purpose of the paper is to generate awareness debate and possibly some action.