Influence of Peak Strain on Lumbar Bone Mineral Density: An Analysis of 15-Year Physical Activity in Young Males and Females

Abstract

In 83 males and 99 females, the relation between peak strain physical activity (PSPA) from 13 to 27 years and lumbar bone mineral density (LBMD) at age 27 was studied. Physical activity was measured longitudinally by an interview six times between ages 13 and 27. Peak strain scores based on ground reaction forces were developed to quantify all registrated activities for peak strain. LBMD was determined once at age 27. Four PSPA periods were considered: the teenage period (13–17 years), the period between 13 and 21 years, the adult period (21–27 years), and the total period (13–27 years). In multiple linear regression analyses, with body weight and gender as covariates, PSPA appeared to be a significant positive predictor for LBMD at age 27 in both males and females for all analyzed periods. The explained variance of PSPA for LBMD was the highest (25%) for the total period and the lowest (8%) for the teenage period.

Relationship between physical activity and bone mineral status in young adults: the Northern Ireland young hearts project

“…Although little work has been carried out on population-based samples, 8,26,32 high strain certainly appears to be a powerful osteogenic stimulus. 16 Some sports, for example those involving high-intensity weight-bearing exercise, or high peak strains, appear to provide better opportunities for maximizing bone than others.…”

“…Peak strain scores were based on ground reaction forces of physical activities and were classified according to the method of Groothausen et al 8 This method assigns four levels of peak strain: vigorous activities involving jumping actions have a peak strain score of 3; activities that involve repetitive sprinting and turning have a peak strain score of 2; other weight-bearing activities have a peak score of 1; and all other activities have a peak strain score of 0. By the method of Groothausen et al 8 peak scores of all recorded activities were either summed to give a total peak strain score or the highest peak score was selected. This method only accounted for activities undertaken during the previous 3 month period, however, and failed to discriminate among differences in the duration and frequency at which the peak strain activities were undertaken.…”

“…16,20 Although it is recognized that bone mineral status is primarily under genetic influence, 15,25 modifiable lifestyle factors, 26 of which physical activity may well be the most important, can have a major impact on bone development, maintenance, and strength. 5,6,8,18,28,32 Recent evidence suggests that weight-bearing physical activity may confer greater benefits on bone status than non-weightbearing activity. 8,30 In addition, activities involving considerable impact or strain have been shown to stimulate osteogenic responses.…”

“…5,6,8,18,28,32 Recent evidence suggests that weight-bearing physical activity may confer greater benefits on bone status than non-weightbearing activity. 8,30 In addition, activities involving considerable impact or strain have been shown to stimulate osteogenic responses. 12,16,27 However, of the studies to date, many have been carried out with athletes 11,18 and older age groups, 12 or have used small sample sizes, 2,7 and are not representative of young adult populations.…”

Current and past menstrual status is an important determinant of femoral neck geometry in exercising women

“…For the mechanical impact category, a classification system by Torstveit and Sundgot-Borgen [41] and based on the method by Groothausen and Siemer [42] was used. The primary sport of each woman was categorized as "low impact," "moderate impact," or "high impact."…”