Format

Send to

Choose Destination
Osteoporos Int. 2017 Jul;28(7):2155-2165. doi: 10.1007/s00198-017-4029-9. Epub 2017 Apr 10.

Progressive skeletal benefits of physical activity when young as assessed at the midshaft humerus in male baseball players.

Author information

1
Department of Physical Therapy, School of Health and Rehabilitation Sciences, Indiana University, 1140 W. Michigan St., CF-120, Indianapolis, IN, 46202, USA. stwarden@iupui.edu.
2
Center for Translational Musculoskeletal Research, School of Health and Rehabilitation Sciences, Indiana University, Indianapolis, IN, 46202, USA. stwarden@iupui.edu.
3
Center for Translational Musculoskeletal Research, School of Health and Rehabilitation Sciences, Indiana University, Indianapolis, IN, 46202, USA.
4
Department of Kinesiology and Sport, Pott College of Science, Engineering, and Education, University of Southern Indiana, Evansville, IN, 47712, USA.
5
Department of Physical Therapy, School of Health and Rehabilitation Sciences, Indiana University, 1140 W. Michigan St., CF-120, Indianapolis, IN, 46202, USA.

Abstract

Physical activity benefits the skeleton, but there is contrasting evidence regarding whether benefits differ at different stages of growth. The current study demonstrates that physical activity should be encouraged at the earliest age possible and be continued into early adulthood to gain most skeletal benefits.

INTRODUCTION:

The current study explored physical activity-induced bone adaptation at different stages of somatic maturity by comparing side-to-side differences in midshaft humerus properties between male throwing athletes and controls. Throwers present an internally controlled model, while inclusion of control subjects removes normal arm dominance influences.

METHODS:

Throwing athletes (n = 90) and controls (n = 51) were categorized into maturity groups (pre, peri, post-early, post-mid, and post-late) based on estimated years from peak height velocity (<-2, -2 to 2, 2 to 4, 4 to 10, and >10 years). Side-to-side percent differences in midshaft humerus cortical volumetric bone mineral density (Ct.vBMD) and bone mineral content (Ct.BMC); total (Tt.Ar), medullary (Me.Ar), and cortical (Ct.Ar) areas; average cortical thickness (Ct.Th); and polar Strength Strain Index (SSIP) were assessed.

RESULTS:

Significant interactions between physical activity and maturity on side-to-side differences in Ct.BMC, Tt.Ar, Ct.Ar, Me.Ar, Ct.Th, and SSIP resulted from the following: (1) greater throwing-to-nonthrowing arm differences than dominant-to-nondominant arm differences in controls (all p < 0.05) and (2) throwing-to-nonthrowing arm differences in throwers being progressively greater across maturity groups (all p < 0.05). Regional analyses revealed greatest adaptation in medial and lateral sectors, particularly in the three post-maturity groups. Years throwing predicted 59% of the variance of the variance in throwing-to-nonthrowing arm difference in SSIP (p < 0.001).

CONCLUSION:

These data suggest that physical activity has skeletal benefits beginning prior to and continuing beyond somatic maturation and that a longer duration of exposure to physical activity has cumulative skeletal benefits. Thus, physical activity should be encouraged at the earliest age possible and be continued into early adulthood to optimize skeletal benefits.

KEYWORDS:

Biomechanics; Exercise; Growth; Mechanical loading; Osteoporosis; Puberty

PMID:
28396902
PMCID:
PMC6052787
DOI:
10.1007/s00198-017-4029-9
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Springer Icon for PubMed Central
Loading ...
Support Center