Ranking of osteogenic potential of physical exercises in postmenopausal women based on femoral neck strains

Abstract

The current study aimed to assess the potential of different exercises triggering an osteogenic response at the femoral neck in a group of postmenopausal women. The osteogenic potential was determined by ranking the peak hip contact forces (HCFs) and consequent peak tensile and compressive strains at the superior and inferior part of the femoral neck during activities such as (fast) walking, running and resistance training exercises. Results indicate that fast walking (5–6 km/h) running and hopping induced significantly higher strains at the femoral neck than walking at 4 km/h which is considered a baseline exercise for bone preservation. Exercises with a high fracture risk such as hopping, need to be considered carefully especially in a frail elderly population and may therefore not be suitable as a training exercise. Since superior femoral neck frailness is related to elevated hip fracture risk, exercises such as fast walking (above 5 km/h) and running can be highly recommended to stimulate this particular area. Our results suggest that a training program including fast walking (above 5 km/h) and running exercises may increase or preserve the bone mineral density (BMD) at the femoral neck.

Muscle and bone mass in middle‐aged women: role of menopausal status and physical activity

“…Intervention studies show that regular physical activity several times a week is effective in increasing femoral neck BMD in women during their postmenopausal years . However, to induce osteogenic effects on the femoral neck, intensive physical exercise such as brisk walking, running and jumping, or high‐load resistance training targeting the hip region is required. For example, habitual walking at 4 km/h is not associated with improved hip BMD …”

Modelling Human Locomotion to Inform Exercise Prescription for Osteoporosis

“…Images were obtained using time-elapsed synchrotron-light microcomputed-tomography [30] − 2.5) combining body anatomy from full-body CT imaging and dissection and a structural model of the femur experimentally validated (R 2 = 0.95) later used for studying different exercises [22]. Other studies fitted a generic bone density map to a cohort reporting limited information on model validity [36,37]. Therefore, it appears that validated models can be used to study the amount of strain under prescribed forces in participants while different technologies may enable ranking of exercise types.…”

“…Regarding model consistency, comparison between models is complicated by the limited number of studies analysed here, different procedures used for modelling femoral mechanics, often incomplete information of exercise kinematic and dynamic and by different mechanical variables for assessment. For example, different studies used principal strain components [36], effective strain [10••], strain energy density per unit of bone mass [22] and strain averages over different bone volumes [10••, 37]. To date, there is no gold standard for comprehensive verification of modelled lower limb muscle forces, except at the triceps surae [50] and quadriceps [51,52], and limited verification data for hip contact forces [53] and femoral strain [54].…”

Effect of anatomical variability on stress‐shielding induced by short calcar‐guided stems: Automated finite element analysis of 90 femora

“…Finally, material properties were assigned in Mimics based on the Hounsfield units (HU) from the CT scan. The HUs were divided over 20 material categories and converted to apparent density (ρ) assuming a linear relationship . The density‐modulus relationship from Morgan et al ( E = 6850 ρ 1.49 ) was used to determine the Young's modulus for each material category and the Poisson ratio of bone was set at 0.3.…”

“…The HUs were divided over 20 material categories and converted to apparent density (r) assuming a linear relationship. 12 The density-modulus relationship from Morgan et al 13 (E ¼ 6850 r 1.49 ) was used to determine the Young's modulus for each material category and the Poisson ratio of bone was set at 0.3. The titanium stem was assigned a uniform Young's modulus of 115 GPa and a Poisson ratio of 0.3.…”