STIMULATION OF BONE GROWTH & PHYSICAL ACTIVITY

 Stimulation Of Bone Growth Through Physical Activity

Stimulation Of Bone Growth Through Physical Activity

Introduction

Bone is the main weight bearing tissue of the body and functions to withstand mechanical forces several times the weight of the body. Despite the numerous shapes and sizes of the bones in the body, bone tissue is structurally and microscopically similar throughout. Bone tissue exists in two general forms: Cortical bone composes the shell of many of the long bones and has low porosity and high density and strength. Cancellous (or tra-becular) bone is found at the ends of long bones or in low weight bearing areas (such as the lower jaw) and is composed of microscopic interconnecting bony trabecula, giving macroscopically high porosity and low density (Grimberg, 2005).

Although bone tissue is generally thought of as a rigid structure, it contains both elastic and stiff components. The bone extracellular matrix is approximately 65 percent inorganic, mainly calcium and phosphate in the form of hydroxyapatite, and 35 percent organic matrix (osteoid), mainly collagen, which is a ropelike fiber. This general composition gives bone marked rigidity while retaining some elasticity, with the collagen fibers of the organic matrix providing high tensile strength to resist pulling forces and the inorganic mineral providing high compressive strength to resist crushing forces (Chatelain, 2002).

Discussion

Child growth is internationally recognized as an important public health indicator for monitoring nutritional status and health in populations. Growth is influenced by many factors such as heredity, genetic or congenital, illness and medications, nutrition, hormones, and psychosocial environment. Measurements of growth height and weight are a very inexpensive service that should be offered by all health-care providers rendering care to children (Izaks, 2003).

The internationally recommended way to assess malnutrition at population level is to take body or anthropometric measurements (e.g., weight and height). Based on combinations of these body measurements, anthropometric indices are constructed. These indices are essential for the interpretation of body measurements as, for example, weight alone has no meaning unless it is related to an individual's age or height. In children, the three most commonly used anthropometric indices are weight for height, height forage, and weight for age. These indices can be expressed in terms of z-scores, percentiles, or percentage of median, which enable comparison of a child or a group of children with a reference population (Kaplan, 1990).

A normal growth pattern does not guarantee overall health; however, children with abnormal growth patterns frequently have nutritional complications of specific clinical disorders (e.g., cystic fibrosis, inflammatory bowel disease) or poor socioeconomic conditions. A child who is two standard deviations (SDs) or more below the mean height for children of that sex and chronologic age (and ideally of the same racial ethnic group) is said to have short stature. A single measurement of height is much less important in assessing growth than is the pattern of growth over a period of time; the key finding is slowed growth that progressively deviates from a previously defined growth channel (or percentile) (Lakatta, ...