Effectiveness of a School-Based Physical Activity Intervention for Increasing Bone Strength in Children: Action Schools! British Columbia

Introduction: Osteoporosis and related fracture are significant societal health burdens. Physical activity during childhood can result in significant bone health benefits, which may reduce the risk for osteoporosis later in life. Aim: The primary aim was to evaluate the effectiveness of a school-based physical activity model, Action Schools! BC (AS! BC), for enhancing bone mass and strength in boys and girls using novel bone imaging technologies.

Methods:

Design and Participants: This was a 16-month cluster randomized, controlled, school-based intervention. Ten schools were randomized to Intervention (INT, 7 schools) or Control (CON, 3 schools). The bone-loading component of AS! BC was a daily, high-impact jumping program (Bounce at the Bell) plus 15 minutes/day of classroom physical activity. Participants were 514 children aged 9-11 years at baseline.

Bone Measurements: Tibial bone strength was assessed with peripheral quantitative computed tomography. Dual energy x-ray absorptiometry and hip structure analysis were used to assess femoral neck bone mineral content (BMC) and bone strength, respectively.

Results

Part 1: Cross-sectional Comparisons In pre- and early pubertal boys tibial bone strength was 5-15% greater than in pre- and early pubertal girls. After adjusting for tibial length, muscle cross-sectional area was the primary explanatory variable of bone strength in both sexes.

Part 2: 16-Month Change - Tibial Bone Strength Intervention boys (n = 147) tended to have greater gains in tibial bone strength than CON boys (n = 64); however, the intervention effect was only significant for prepubertal boys at the distal tibia. Action Schools! BC was not effective for increasing tibial bone strength in girls (n = 137 INT, 65 CON).

Part 3: 16-Month Change - Femoral Neck Bone Mass and Strength Intervention girls tended to have greater gains in femoral neck bone strength and BMC than CON girls; however, the difference in change between groups was not significant. Action Schools! BC was not effective for increasing femoral neck bone mass or strength in boys.

Summary: Skeletal adaptations to the AS! BC intervention were sex-, maturity- and site-specific. Action Schools! BC offers promise as a simple and inexpensive strategy for increasing bone mass and strength in boys and girls.

Year	Entry
1997	Umemura Y, Ishiko T, Yamauchi T, Kurono M, Mashiko S. Five jumps per day increase bone mass and breaking force in rats. J Bone Miner Res. September 1997;12(10):1480-1485.
2002	Currey JD. Bones: Structure and Mechanics. Princeton, NJ: Princeton University Press; 2002.
1996	Kannus P, Parkkari J, Sievänen H, Heinonen A, Vuori I, Järvinen M. Epidemiology of hip fractures. Bone. January 1996;18(1)(suppl):57S-63S.
1995	Kannus P, Haapasalo H, Sankelo M, Sievanen H, Pasanen M, Heinonen A, Oja P, Vuori I. Effect of starting age of physical activity on bone mass in the dominant arm of tennis and squash players. Ann Intern Med. July 1995;123(1):27-31.
2002	Lochmüller E-M, Groll O, Kuhn V, Eckstein F. Mechanical strength of the proximal femur as predicted from geometric and densitometric bone properties at the lower limb versus the distal radius. Bone. January 2002;30(1):207-216.
1985	Kleerekoper M, Villanueva AR, Stanciu J, Rao DS, Parfitt AM. The role of three-dimensional trabecular microstructure in the pathogenesis of vertebral compression fractures. Calcif Tiss Int. 1985;37(6):594-597.
1996	Genant HK, Engelke K, Fuerst T, Glüer C, Grampp S, Harris ST, Jergas M, Lang T, Lu Y, Majumdar S, Mathur A, Takada M. Noninvasive assessment of bone mineral and structure: state of the art. J Bone Miner Res. June 1996;11(6):707-730.
2001	Currey JD. Bone strength: what are we trying to measure? Calcif Tiss Int. April 2001;68(4):205-210.
2002	Cummings SR, Melton LJ III. Epidemiology and outcomes of osteoporotic fractures. Lancet. May 18, 2002;359(9319):1761-1767.
2004	Pearson OM, Lieberman DE. The aging of Wolff's "law": ontogeny and responses to mechanical loading in cortical bone. Yearb Phys Anthropol. 2004;47:63-99.
2000	Haapasalo H, Kontulainen S, Sievänen H, Kannus P, Järvinen M, Vuori I. Exercise-induced bone gain is due to enlargement in bone size without a change in volumetric bone density: a peripheral quantitative computed tomography study of the upper arms of male tennis players. Bone. September 2000;27(3):351-357.
2006	Ashe MC, Khan KM, Kontulainen SA, Guy P, Liu D, Beck TJ, McKay HA. Accuracy of pQCT for evaluating the aged human radius: an ashing, histomorphometry and failure load investigation. Osteoporos Int. August 2006;17(8):1241-1251.
1999	Bailey DA, Mckay HA, Mirwald RL, Crocker PRE, Faulkner RA. A six-year longitudinal study of the relationship of physical activity to bone mineral accrual in growing children: the University of Saskatchewan bone mineral accrual study. J Bone Miner Res. October 1999;14(10):1672-1679.
2003	Seeman E. Periosteal bone formation: a neglected determinant of bone strength. NEJM. July 24, 2003;349(4):320-323.
2002	Seeman E. Pathogenesis of bone fragility in women and men. Lancet. May 25, 2002;359(9320):1841-1850.
2001	Seeman E. Sexual dimorphism in skeletal size, density, and strength. J Clin Endocrinol Metab. October 2001;86(10):4576-4584.
1999	Burger EH, Klein-Nulend J. Mechanotransduction in bone: role of the lacunocanalicular network. FASEB J. May 1999;12(9001):S101-S112.
1998	Turner CH. Three rules for bone adaptation to mechanical stimuli. Bone. November 1998;23(5):399-407.
2001	Cowin SC. The false premise of Wolff's Law. In: Cowin SC, ed. Bone Mechanics Handbook. 2nd ed. Boca Raton, FL: CRC Press; 2001:chap 30.
1990	Beck TJ, Ruff CB, Warden KE, Scott wW Jr, Rao GU. Predicting femoral neck strength from bone mineral data: a structural approach. Invest Radiol. January 1990;25(1):6-18.
1996	Marshall D, Johnell O, Wedel H. Meta-analysis of how well measures of bone mineral density predict occurrence of osteoporotic fractures. BMJ. May 18, 1996;312(7041):1254-1259.
1992	Lanyon LE. The success and failure of the adaptive response to functional load-bearing in averting bone fracture. Bone. 1992;13(2):S17-S21.
2000	Rauch F, Travers R, Parfitt AM, Glorieux FH. Static and dynamic bone histomorphometry in children with osteogenesis imperfecta. Bone. June 2000;26(6):581-589.
1996	Lanyon LE. Using functional loading to influence bone mass and architecture: objectives, mechanisms, and relationship with estrogen of the mechanically adaptive process in bone. Bone. January 1996;18(1)(suppl):37S-43S.
1997	Burr DB. Muscle strength, bone mass, and age‐related bone loss. J Bone Miner Res. 1997;12(10):1547-1551.
1991	Martin RB. Determinants of the mechanical properties of bones. J Biomech. 1991;24(suppl 1):79-88.
2003	Turner CH, Robling AG. Designing exercise regimens to increase bone strength. Exerc Sport Sci Rev. January 2003;31(1):45-50.
1998	Martin RB, Burr DB, Sharkey NA. Skeletal Tissue Mechanics. New York, NY: Springer-Verlag; 1998.
2002	Riggs BL, Khosla S, Melton LJ III. Sex steroids and the construction and conservation of the adult skeleton. Endocr Rev. June 2002;23(3):279-302.
2003	Currey JD. The many adaptations of bone. J Biomech. 2003;36(10):1487-1495.
1996	Burr DB, Milgrom C, Fyhrie D, Forwood M, Nyska M, Finestone A, Hoshaw S, Saiag E, Simkin A. In vivo measurement of human tibial strains during vigorous activity. Bone. May 1996;18(5):405-410.
2003	Currey JD. How well are bones designed to resist fracture? J Bone Miner Res. April 2003;18(4):591-598.
1997	Judex S, Gross TS, Zernicke RF. Strain gradients correlate with sites of exercise‐induced bone‐forming surfaces in the adult skeleton. J Bone Miner Res. October 1997;12(10):1737-1745.
1992	Carter DR, Bouxsein ML, Marcus R. New approaches for interpreting projected bone densitometry data. J Bone Miner Res. February 1992;7(2):137-145.
1998	Turner CH, Pavalko FM. Mechanotransduction and functional response of the skeleton to physical stress: the mechanisms and mechanics of bone adaptation. J Orthop Sci. November 1998;3(6):346-355.
1993	Cummings SR, Black DM, Nevitt MC, Browner W, Cauley J, Ensrud K, Genant HK, Palmero L, Scott J, Vogt TM; Study of Osteoporotic Fractures Research Group. Bone density at various sites for prediction of hip fractures. Lancet. January 9, 1993;341(8837):72-75.
1975	Currey JD, Butler G. The mechanical properties of bone tissue in children. J Bone Joint Surg. September 1975;57A(6):810-814.
1980	Lanyon LE. The influence of function on the development of bone curvature: an experimental study on the rat tibia. J Zool. 1980;192(4):457-466.
1996	Hangartner TN, Gilsanz V. Evaluation of cortical bone by computed tomography. J Bone Miner Res. October 1996;11(10):1518-1525.
1987	Goldstein SA. The mechanical properties of trabecular bone: dependence on anatomic location and function. J Biomech. 1987;20(11-12):1055-1061.
1987	Lanyon LE. Functional strain in bone tissue as an objective, and controlling stimulus for adaptive bone remodelling. J Biomech. 1987;20(11-12):1083-1093.
1986	Lanyon LE, Rubin CT, Baust G. Modulation of bone loss during calcium insufficiency by controlled dynamic loading. Calcif Tiss Int. July 1986;38(4):209-216.
2001	Fuchs RK, Bauer JJ, Snow CM. Jumping improves hip and lumbar spine bone mass in prepubescent children: a randomized controlled trial. J Bone Miner Res. January 2001;16(1):148-156.
1986	Jaworski ZFG, Uhthoff HK. Reversibility of nontraumatic disuse osteoporosis during its active phase. Bone. January 1986;7(6):431.
1984	Martin RB, Burr DB. Non-invasive measurement of long bone cross-sectional moment of inertia by photon absorptiometry. J Biomech. 1984;17(3):195-201.
1985	Rubin CT, Lanyon LE. Regulation of bone mass by mechanical strain magnitude. Calcif Tiss Int. 1985;37(4):411-417.
1984	Rubin CT, Lanyon LE. Regulation of bone formation by applied dynamic loads. J Bone Joint Surg. March 1984;66A(3):397-402.
1989	Weinreb M, Rodan GA, Thompson DD. Osteopenia in the immobilized rat hind limb is associated with increased bone resorption and decreased bone formation. Bone. 1989;10(3):187-194.
1997	Mosley JR, March BM, Lynch J, Lanyon LE. Strain magnitude related changes in whole bone architecture in growing rats. Bone. March 1997;20(3):191-198.
1998	Mosley JR, Lanyon LE. Strain rate as a controlling influence on adaptive modeling in response to dynamic loading of the ulna in growing male rats. Bone. October 1998;23(4):313-318.
2001	Robling AG, Burr DB, Turner CH. Recovery periods restore mechanosensitivity to dynamically loaded bone. J Exp Biol. 2001;204(19):3389-3399.
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2002	Petit MA, Mckay HA, MacKelvie KJ, Heinonen A, Khan KM, Beck TJ. A randomized school-based jumping intervention confers site and maturity-specific benefits on bone structural properties in girls: a hip structural analysis study. J Bone Miner Res. March 2002;17(3):363-372.
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Year

Entry

1997

Umemura Y, Ishiko T, Yamauchi T, Kurono M, Mashiko S. Five jumps per day increase bone mass and breaking force in rats. J Bone Miner Res. September 1997;12(10):1480-1485.

2002

Currey JD. Bones: Structure and Mechanics. Princeton, NJ: Princeton University Press; 2002.

1996

Kannus P, Parkkari J, Sievänen H, Heinonen A, Vuori I, Järvinen M. Epidemiology of hip fractures. Bone. January 1996;18(1)(suppl):57S-63S.

1995

Kannus P, Haapasalo H, Sankelo M, Sievanen H, Pasanen M, Heinonen A, Oja P, Vuori I. Effect of starting age of physical activity on bone mass in the dominant arm of tennis and squash players. Ann Intern Med. July 1995;123(1):27-31.

2002

Lochmüller E-M, Groll O, Kuhn V, Eckstein F. Mechanical strength of the proximal femur as predicted from geometric and densitometric bone properties at the lower limb versus the distal radius. Bone. January 2002;30(1):207-216.

1985

Kleerekoper M, Villanueva AR, Stanciu J, Rao DS, Parfitt AM. The role of three-dimensional trabecular microstructure in the pathogenesis of vertebral compression fractures. Calcif Tiss Int. 1985;37(6):594-597.

1996

Genant HK, Engelke K, Fuerst T, Glüer C, Grampp S, Harris ST, Jergas M, Lang T, Lu Y, Majumdar S, Mathur A, Takada M. Noninvasive assessment of bone mineral and structure: state of the art. J Bone Miner Res. June 1996;11(6):707-730.

2001

Currey JD. Bone strength: what are we trying to measure? Calcif Tiss Int. April 2001;68(4):205-210.

2002

Cummings SR, Melton LJ III. Epidemiology and outcomes of osteoporotic fractures. Lancet. May 18, 2002;359(9319):1761-1767.

2004

Pearson OM, Lieberman DE. The aging of Wolff's "law": ontogeny and responses to mechanical loading in cortical bone. Yearb Phys Anthropol. 2004;47:63-99.

2000

Haapasalo H, Kontulainen S, Sievänen H, Kannus P, Järvinen M, Vuori I. Exercise-induced bone gain is due to enlargement in bone size without a change in volumetric bone density: a peripheral quantitative computed tomography study of the upper arms of male tennis players. Bone. September 2000;27(3):351-357.

2006

Ashe MC, Khan KM, Kontulainen SA, Guy P, Liu D, Beck TJ, McKay HA. Accuracy of pQCT for evaluating the aged human radius: an ashing, histomorphometry and failure load investigation. Osteoporos Int. August 2006;17(8):1241-1251.

1999

Bailey DA, Mckay HA, Mirwald RL, Crocker PRE, Faulkner RA. A six-year longitudinal study of the relationship of physical activity to bone mineral accrual in growing children: the University of Saskatchewan bone mineral accrual study. J Bone Miner Res. October 1999;14(10):1672-1679.

2003

Seeman E. Periosteal bone formation: a neglected determinant of bone strength. NEJM. July 24, 2003;349(4):320-323.

2002

Seeman E. Pathogenesis of bone fragility in women and men. Lancet. May 25, 2002;359(9320):1841-1850.

2001

Seeman E. Sexual dimorphism in skeletal size, density, and strength. J Clin Endocrinol Metab. October 2001;86(10):4576-4584.

1999

Burger EH, Klein-Nulend J. Mechanotransduction in bone: role of the lacunocanalicular network. FASEB J. May 1999;12(9001):S101-S112.

1998

Turner CH. Three rules for bone adaptation to mechanical stimuli. Bone. November 1998;23(5):399-407.

2001

Cowin SC. The false premise of Wolff's Law. In: Cowin SC, ed. Bone Mechanics Handbook. 2nd ed. Boca Raton, FL: CRC Press; 2001:chap 30.

1990

Beck TJ, Ruff CB, Warden KE, Scott wW Jr, Rao GU. Predicting femoral neck strength from bone mineral data: a structural approach. Invest Radiol. January 1990;25(1):6-18.

1996

Marshall D, Johnell O, Wedel H. Meta-analysis of how well measures of bone mineral density predict occurrence of osteoporotic fractures. BMJ. May 18, 1996;312(7041):1254-1259.

1992

Lanyon LE. The success and failure of the adaptive response to functional load-bearing in averting bone fracture. Bone. 1992;13(2):S17-S21.

2000

Rauch F, Travers R, Parfitt AM, Glorieux FH. Static and dynamic bone histomorphometry in children with osteogenesis imperfecta. Bone. June 2000;26(6):581-589.

1996

Lanyon LE. Using functional loading to influence bone mass and architecture: objectives, mechanisms, and relationship with estrogen of the mechanically adaptive process in bone. Bone. January 1996;18(1)(suppl):37S-43S.

1997

Burr DB. Muscle strength, bone mass, and age‐related bone loss. J Bone Miner Res. 1997;12(10):1547-1551.

1991

Martin RB. Determinants of the mechanical properties of bones. J Biomech. 1991;24(suppl 1):79-88.

2003

Turner CH, Robling AG. Designing exercise regimens to increase bone strength. Exerc Sport Sci Rev. January 2003;31(1):45-50.

1998

Martin RB, Burr DB, Sharkey NA. Skeletal Tissue Mechanics. New York, NY: Springer-Verlag; 1998.

2002

Riggs BL, Khosla S, Melton LJ III. Sex steroids and the construction and conservation of the adult skeleton. Endocr Rev. June 2002;23(3):279-302.

2003

Currey JD. The many adaptations of bone. J Biomech. 2003;36(10):1487-1495.

1996

Burr DB, Milgrom C, Fyhrie D, Forwood M, Nyska M, Finestone A, Hoshaw S, Saiag E, Simkin A. In vivo measurement of human tibial strains during vigorous activity. Bone. May 1996;18(5):405-410.

2003

Currey JD. How well are bones designed to resist fracture? J Bone Miner Res. April 2003;18(4):591-598.

1997

Judex S, Gross TS, Zernicke RF. Strain gradients correlate with sites of exercise‐induced bone‐forming surfaces in the adult skeleton. J Bone Miner Res. October 1997;12(10):1737-1745.

1992

Carter DR, Bouxsein ML, Marcus R. New approaches for interpreting projected bone densitometry data. J Bone Miner Res. February 1992;7(2):137-145.

1998

Turner CH, Pavalko FM. Mechanotransduction and functional response of the skeleton to physical stress: the mechanisms and mechanics of bone adaptation. J Orthop Sci. November 1998;3(6):346-355.

1993

Cummings SR, Black DM, Nevitt MC, Browner W, Cauley J, Ensrud K, Genant HK, Palmero L, Scott J, Vogt TM; Study of Osteoporotic Fractures Research Group. Bone density at various sites for prediction of hip fractures. Lancet. January 9, 1993;341(8837):72-75.

1975

Currey JD, Butler G. The mechanical properties of bone tissue in children. J Bone Joint Surg. September 1975;57A(6):810-814.

1980

Lanyon LE. The influence of function on the development of bone curvature: an experimental study on the rat tibia. J Zool. 1980;192(4):457-466.

1996

Hangartner TN, Gilsanz V. Evaluation of cortical bone by computed tomography. J Bone Miner Res. October 1996;11(10):1518-1525.

1987

Goldstein SA. The mechanical properties of trabecular bone: dependence on anatomic location and function. J Biomech. 1987;20(11-12):1055-1061.

1987

Lanyon LE. Functional strain in bone tissue as an objective, and controlling stimulus for adaptive bone remodelling. J Biomech. 1987;20(11-12):1083-1093.

1986

Lanyon LE, Rubin CT, Baust G. Modulation of bone loss during calcium insufficiency by controlled dynamic loading. Calcif Tiss Int. July 1986;38(4):209-216.

2001

Fuchs RK, Bauer JJ, Snow CM. Jumping improves hip and lumbar spine bone mass in prepubescent children: a randomized controlled trial. J Bone Miner Res. January 2001;16(1):148-156.

1986

Jaworski ZFG, Uhthoff HK. Reversibility of nontraumatic disuse osteoporosis during its active phase. Bone. January 1986;7(6):431.

1984

Martin RB, Burr DB. Non-invasive measurement of long bone cross-sectional moment of inertia by photon absorptiometry. J Biomech. 1984;17(3):195-201.

1985

Rubin CT, Lanyon LE. Regulation of bone mass by mechanical strain magnitude. Calcif Tiss Int. 1985;37(4):411-417.

1984

Rubin CT, Lanyon LE. Regulation of bone formation by applied dynamic loads. J Bone Joint Surg. March 1984;66A(3):397-402.

1989

Weinreb M, Rodan GA, Thompson DD. Osteopenia in the immobilized rat hind limb is associated with increased bone resorption and decreased bone formation. Bone. 1989;10(3):187-194.

1997

Mosley JR, March BM, Lynch J, Lanyon LE. Strain magnitude related changes in whole bone architecture in growing rats. Bone. March 1997;20(3):191-198.

1998

Mosley JR, Lanyon LE. Strain rate as a controlling influence on adaptive modeling in response to dynamic loading of the ulna in growing male rats. Bone. October 1998;23(4):313-318.

2001

Robling AG, Burr DB, Turner CH. Recovery periods restore mechanosensitivity to dynamically loaded bone. J Exp Biol. 2001;204(19):3389-3399.

2002

Robling AG, Hinant FM, Burr DB, Turner CH. Improved bone structure and strength after long‐term mechanical loading is greatest if loading is separated into short bouts. J Bone Miner Res. August 2002;17(8):1545-1554.

1994

Parfitt AM. The two faces of growth: benefits and risks to bone integrity. Osteoporos Int. November 1994;4(6):382-398.

1991

Goldstein SA, Matthews LS, Kuhn JL, Hollister SJ. Trabecular bone remodeling: an experimental model. J Biomech. 1991;24(suppl 1):135-150.

1992

Rubin CT, Bain SD, McLeod KJ. Suppression of the osteogenic response in the aging skeleton. Calcif Tiss Int. April 1992;50(4):306-313.

1999

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Year	Entry
2015	Tan VPS. Effects of a School-Based Physical Activity Intervention on Adolescent Bone Strength, Structure and Density: The Health Promoting Secondary Schools (HPSS) Bone Health Study [PhD thesis]. Vancouver, BC: University of British Columbia; June 2015.
2010	Manske SL. Muscle Disuse and Vibration Effects on Bone Morphology [PhD thesis]. Calgary, AB: University of Calgary; December 2010.

Year

Entry

2015

Tan VPS. Effects of a School-Based Physical Activity Intervention on Adolescent Bone Strength, Structure and Density: The Health Promoting Secondary Schools (HPSS) Bone Health Study [PhD thesis]. Vancouver, BC: University of British Columbia; June 2015.

2010

Manske SL. Muscle Disuse and Vibration Effects on Bone Morphology [PhD thesis]. Calgary, AB: University of Calgary; December 2010.