Exercise-based correlates to calcaneal osteogenesis produced by a chronic training intervention.

Area of Science:

• Biomechanics
• Bone Physiology
• Exercise Science

Background:

• Osteoporosis and calcaneal (heel bone) loss pose significant health risks.
• Traditional exercise interventions may not sufficiently stimulate bone accrual.
• Gravity-independent devices offer novel mechanical loading parameters.

Purpose of the Study:

• To investigate the relationship between exercise performance variables and changes in calcaneal bone mineral content (BMC) and bone mineral density (BMD).
• To identify specific exercise parameters that correlate with bone gains using a gravity-independent device.

Main Methods:

• Thirty workouts were performed on a gravity-independent device, including hip extension and seated calf press exercises.
• Calcaneal BMC and BMD changes (delta values) were measured.
• Exercise performance variables, including peak force, peak acceleration, impulse, and dwell times (time between eccentric and concentric phases), were quantified and correlated with bone changes using Pearson Coefficients.

Main Results:

• Significant gains in calcaneal BMC (+29%) and BMD (+33%) were observed after 30 workouts.
• Shorter dwell times in hip extension (workouts 1-12) significantly correlated with greater calcaneal BMC (r=-0.64) and BMD (r=-0.63) gains.
• Shorter dwell times in seated calf press (workouts 1-24) significantly correlated with calcaneal BMC gains (r=-0.48) and showed a trend for BMD gains (r=-0.45).
• No other tested exercise variables correlated significantly with bone changes.

Conclusions:

• Exercise on a gravity-independent device can significantly enhance calcaneal bone mineral density and content.
• Shorter exercise dwell times appear to be a key factor driving bone accrual.
• This technology shows promise for developing interventions to treat and prevent calcaneal bone loss.