1- Cumulative effect of mechanical load on gait and musculoskeletal health in children and adolescents with different morphologies and maturity levels 

Project Leader: Filomena Vieira

Project purposes:

• To test the reliability of the anthropometric, maturational, plantar pressure and postural assessment methodologies used in a previous research
• To validate the questionnaire “Quantification de l‟Activité Physique en Altitude Chez les Enfants”(QAPACE)

Contrary to what one might think, musculoskeletal problems, as clinical conditions, are not confined to the adult population, and there are an unexpected number of children and adolescents who have reported headaches, spine (lumbar and cervical level) and shoulder problems (Niemi et al, 1997;. Salminen, 1984).

During the adolescent growth spurt, period spaning approximately two years where the youth becomes disproportionate (short trunk and longer limbs) and presents a generalized hypotonia (Vieira & Fragoso, 2006), the spine is more susceptible to external influences such as bad sitting postures (classroom, watching TV, playing computer games) and mechanical overload imposed by backpack carriage and vigorous physical activity. Thereby, incidence of musculoskeletal symptoms increase, for example, the antero-posterior and lateral deviations of the spine.

The repercussions that the exposure to mechanical load has on the body are dependent on the internal and external forces magnitude, on the frequency of force application, on the repetition of the load application, and on the way the muscular structures react to the internal forces (Watkins, 1999).

For the majority of the scientific studies, mechanical load refers to external load, and most of the time is associated with vigorous physical activity practice and with school backpack carriage, nevertheless overweigh and obesity in children and adolescents may be considered as important factors of internal overload. These situations have a great impact not only because the prevalence of children and adolescents with overweigh and obesity has increased significantly in the last decades, but also due to their significant health repercussions (great incidence of chronic disease and musculoskeletal symptoms).

In this sense it is important to understand, in a prospective study, the short and long term repercussions of the mechanical load on the ground reactions forces, the plantar pressure distribution and the prevalence of musculoskeletal symptoms in children and adolescents with different morphologies and maturity levels.

In this three year study, started in 2012/2013 we specifically intend to:

• Establish the children and adolescents morphological, maturational and physical activity profile by age and gender, in each school year;
• Evaluate the morphological, maturational and physical activity changes by age and gender, over a three year period;
• Establish the plantar pressure distribution pattern during gait, by age and gender, in each school year;
• Establish the plantar pressure distribution changes during gait, by age and gender, over a three year period;
• Determine the prevalence of overweight and obesity situations, by age and gender, in each school year;
• Evaluate the changes on the prevalence of overweight and obesity situations, by age and gender, over a three year period;
• Determine the prevalence of musculoskeletal symptoms on spine and lower limbs, by age and gender, in each school year;
• Verify the effect of physical activity level and backpack carriage on both plantar pressure distribution during gait and musculoskeletal symptoms on spine and lower limbs in each school year, over a three year period;
• Verify the effect of the morphologic type and the BMI on both plantar pressure distribution during gait and musculoskeletal symptoms on spine and lower limbs in each school year, over a three year period;
• Analyze the association of morphological, maturational and physical activity parameters with both the plantar pressure distribution during gait and the musculoskeletal symptoms.