Table 7.

Characteristics of subgroup of non-weight bearing participants and healthy volunteers. Only female participants were included in this comparison to prevent confounding due to large differences in muscle parameters between genders. Data are presented mean ± SD unless otherwise stated. Percentage differences between mean values are presented. Statistical significance set at p < 0.05, highlighted by p values in bold font

Characteristics	Sub-group of non-weight bearing participants (n = 36)	Healthy older volunteers (n = 11)	p value	Percentage difference
Age (years)	83.9 ± 7.4	77.5 ± 6.1	0.016
Age range (years)	70–99	70–89
Number of comorbidities (median and IQR)	6 (4–8)	3 (0–4)	< 0.001
Previous post-menopausal fractures (no. of participants and %)	20 (67%)	4 (36%)	0.265
Number of medications (median and IQR)	6 (3–7)	2 (1–4)	0.025
Use of walking aid (n, %)	26 (72%)	0	< 0.001
FRAIL scale (n, %)
Robust   Pre-frail   Frail	4 (11%) 14 (39%) 18 (50%)	11 (100%) 0 0	< 0.001
Muscle strength measures
Handgrip strength (kg)	8.94 ± 4.9a	19.9 ± 5.8	< 0.001	76.0%
Knee extension strength (kg)	4.5 ± 1.5b	7.8 ± 1.3	< 0.001	53.7%
Body composition including BIA
Body mass index (kg/m2)	24.4 ± 5.7	25.0 ± 2.8	0.632
Body fat percentage	37.4 ± 7.5c	36.2 ± 6.2	0.639	3.2%
Appendicular skeletal muscle mass index (ASMI) (kg/m2)	8.47 ± 3.50c	8.01 ± 0.64	0.467	5.6%
VL Muscle ultrasound parameters
Muscle thickness (cm)	1.38 ± 0.47	1.75 ± 0.29	0.005	23.6%
Muscle cross-sectional area (cm2)	8.92 ± 4.37d	13.35 ± 3.97	0.005	39.8%
Echogenicity (greyscale units)	98.4 ± 20.5e	68.7 ± 14.1	< 0.001	35.5%

^aTotal n = 35 (1 participant unable to perform as had acute fractures in both arms), ^btotal n = 35 (1 participant unable to perform as had acute fractures in both legs), ^ctotal n = 35 (1 participant measure contraindicated due to permanent pacemaker), ^dtotal n = 33, ^etotal n = 30