Predicting Diaphyseal Cortical Bone Status Using Measures of Muscle Force Capacity

Abstract

MCSA is a strong independent predictor of cortical bone structure; however, both laboratory- and field-based measures of peak torque and/or peak anaerobic power are promising alternatives, explaining similar and sometimes greater variance than MCSA.

Sex-Specific Muscular Mediation of the Relationship Between Physical Activity and Cortical Bone in Young Adults

“…Assumptions of mediation are similar to that of multiple regression, including linearity, homoscedasticity, normality of estimation error, and independence of observations. (16) As is depicted in Fig. However, it is important to note that results from path analysis using non-experimental data should be interpreted with caution, because causal inference is not appropriate for observational data.…”

“…(16) Briefly, participants (n = 147; n = 77 female) were aged 18 to 21 years to ensure that most had achieved the majority of their longitudinal growth and skeletal maturation, minimizing the effect of maturational differences on cortical outcomes. (16) Briefly, participants (n = 147; n = 77 female) were aged 18 to 21 years to ensure that most had achieved the majority of their longitudinal growth and skeletal maturation, minimizing the effect of maturational differences on cortical outcomes.…”

“…(16) Potential participants (n = 344) were contacted via email, of which (n = 184) were scheduled for testing. (16) Potential participants (n = 344) were contacted via email, of which (n = 184) were scheduled for testing.…”

“…Participants included within this cross-sectional analysis were recruited via email, posted flyer, and word-of-mouth advertising from fall 2016 to spring 2017, as described. (16) Briefly, participants (n = 147; n = 77 female) were aged 18 to 21 years to ensure that most had achieved the majority of their longitudinal growth and skeletal maturation, minimizing the effect of maturational differences on cortical outcomes. (23,24) Inclusion criteria also dictated that participants were (i) free of orthopaedic limitations that precluded participation in exercise and PA; (ii) not current smokers (past 6 months); (iii) not pregnant or planning to become pregnant for the duration of their participation, and had not given birth in the last 12 months; (iv) not taking medications known to affect bone metabolism (ie, glucocorticoids), habitual dietary intake, or PA; (v) free of any medical conditions know to affect bone metabolism (ie, Crohn's disease); (vi) not currently diagnosed with an eating disorder; and (vii) had not undergone recent weight-loss surgery (bariatric or gastric bypass).…”

“…Importantly, data in youth and young adults highlight independent roles of muscle size and neuromuscular function (peak muscular forces) as they relate to bone status. (13)(14)(15)(16) Young adult (18 to 21 years) muscle size (2.1% to 7.5%), peak muscular torque (1.0% to 4.5% of variance), and peak power (0.8% to 5.5% of variance) all accounted for unique portions of variance in cortical structural outcomes, independent of time spent in MVPA. Similarly, peak isokinetic torque accounted for 2% to 5% of the variance in bone mineral content, area, and estimated strength, after accounting for leg lean mass and length in children (6.5 to 8.9 year).…”