The correlation of muscle thickness and pennation angle assessed by ultrasound with sarcopenia in elderly Chinese community dwellers

Figures & data

Figure 1 Typical ultrasound images. Transversal ultrasound images of anterior radial muscle and anterior ulnar muscle (A), posterior tibial muscle and posterior fibula muscle (B). Maximal muscle thickness was measured separately between the upper fascia to radius and ulna leading edge or to tibia and fibula trailing edge at the widest distance. Pennation angles were measured between muscle fiber and the deep fascia of the muscle (C and D).

Table 1 Comparison of anthropometrics, MT, PA, muscle mass, grip strength, gait speed and SPPB of the subjects by gender

Characteristic	Male (n=97)	Female (n=168)	p
Age (years)	69.33±6.77	67.79±6.17	0.063
Height (cm)	168.38±5.85	155.58±5.97	<0.001
Weight (kg)	69.06±9.25	58.39±8.52	<0.001
BMI (kg/m^2)	24.34±2.82	24.09±3.04	0.515
Waist circumference (cm)	90.22±8.82	84.70±8.97	<0.001
Hip circumference (cm)	96.55±6.25	95.18±6.02	0.08
Waist-to-hip ratio	0.93±0.06	0.89±0.072	<0.001
MT (muscle thickness) (mm)
Anterior radial	19.44±2.77	15.68±2.24	<0.001
Anterior ulnar	39.24±3.1	33.18±3.17	<0.001
Posterior tibial	57.96±6.2	52.96±5.83	<0.001
Posterior fibula	35.14±7.26	31.51±5.91	<0.001
PA (pennation angle) (°)
Gastrocnemius lateralis	18.95±3.99	18.91±4.47	0.946
Gastrocnemius medialis	24.12±4.65	24.83±5.58	0.292
Muscle mass
LM (kg)	46.5±5.7	33.38±4.34	<0.001
Android LM (kg)	3.38±0.5	2.37±0.39	<0.001
Gynoid LM (kg)	6.99±0.84	5.0±0.73	<0.001
Trunk LM (kg)	22.36±3.09	16.6±2.26	<0.001
Upper limb LM (kg)	5.53±0.89	3.35±0.57	<0.001
Lower limb LM (kg)	14.62±1.99	10.11±1.5	<0.001
aLM (kg)	20.15±2.75	13.45±1.99	<0.001
RASM (kg/m^2)	7.09±0.8	5.55±0.73	<0.001
Grip strength (kg)	38.79±7.93	24.59±4.35	<0.001
Gait speed (m/s)	1.28±0.27	1.27±0.26	0.575
SPPB	11.43±1.15	11.31±1.59	0.525

Notes: Variables are expressed as mean ± SD. p-values were determined using Student’s t test for continuous variables.

Abbreviations: MT, muscle thickness; PA, pennation angle; BMI, body mass index; LM, total lean mass; aLM, appendicular lean mass; RASM, relative appendicular skeletal muscle mass; SPPB, Short Physical Performance Battery.

Table 2 Effects of age on general characteristics, MT, PA, muscle mass, grip strength, gait speed and SPPB

Characteristic	Correlation with age
	Male	Female
BMI	−0.043	−0.109
Waist-to-hip ratio	0.078	0.220**
Anterior radial muscle thickness	−0.236*	−0.211**
Anterior ulnar muscle thickness	−0.148	−0.234**
Posterior tibial muscle thickness	−0.103	−0.209**
Posterior fibula muscle thickness	−0.038	−0.097
PA (gastrocnemius lateralis)	0.112	−0.017
PA (gastrocnemius medialis)	−0.069	−0.055
LM	−0.249*	−0.268***
Android LM	−0.074	−0.243**
Gynoid LM	−0.168	−0.295***
Trunk LM	−0.243*	−0.254***
Upper limb LM	−0.305**	−0.205**
Lower limb LM	−0.193	−0.233**
aLM	−0.239*	−0.234**
RASM	−0.136	−0.059
Grip strength	−0.363***	−0.320***
Gait speed	−0.239*	−0.357***
SPPB	−0.488***	−0.189*

Notes: *p<0.05; **p<0.01; ***p<0.001.

Abbreviations: BMI, body mass index; PA, pennation angle; LM, total lean mass; aLM, appendicular lean mass; RASM, relative appendicular skeletal muscle mass; SPPB, short physical performance battery.

Table 3 Partial correlation between MT, PA and regional LMs, RASM, grip strength, gait speed or SPPB

	Upper limb LM	Lower limb LM	aLM	RASM	Grip strength	Gait speed	SPPB
Male
Muscle thickness
Anterior radial	0.211*	0.247*	0.248*	0.331**	0.259*	0.058	0.016
Anterior ulnar	0.522***	0.425***	0.477***	0.435***	0.494***	−0.033	−0.017
Posterior tibial	0.390***	0.566***	0.539***	0.570***	0.071	−0.022	−0.029
Posterior fibula	0.285**	0.391***	0.377***	0.483***	0.013	0.034	−0.018
PA
Gastrocnemius lateralis	−0.013	−0.110	−0.084	−0.084	−0.025	−0.067	−0.011
Gastrocnemius medialis	−0.083	−0.120	−0.115	−0.042	−0.001	−0.087	−0.072
Female
Muscle thickness
Anterior radial	0.398***	0.267***	0.316***	0.283***	0.165*	0.042	0.027
Anterior ulnar	0.443***	0.408***	0.435***	0.325**	0.323***	0.180*	0.002
Posterior tibial	0.483***	0.524***	0.534***	0.468***	0.236**	0.082	0.026
Posterior fibula	0.452***	0.506***	0.511***	0.498***	0.246**	0.126	−0.031
PA
Gastrocnemius lateralis	−0.044	0.010	−0.005	−0.027	0.063	0.089	0.118
Gastrocnemius medialis	−0.031	0.010	−0.001	−0.029	0.089	0.198*	0.170*

Notes: R correlation coefficient, *p<0.05; **p<0.01; ***p<0.001, Adjustment for age.

Abbreviations: LM, total lean mass; aLM, appendicular lean mass; RASM, relative appendicular skeletal muscle mass; SPPB, short physical performance battery; PA, pennation angle.

Table 4 Multiple linear regression analysis of MT and PA on RASM, grip strength, gait speed or SPPB

Variables	Male			Female
	β	t	p	β	t	p
RASM
Anterior radial muscle thickness	-0.042	-0.498	0.620	0.042	0.575	0.566
Anterior ulnar muscle thickness	0.164	1.952	0.054	0.066	0.856	0.394
Posterior tibial muscle thickness	0.211	2.205	0.030	0.083	0.903	0.368
Posterior fibula muscle thickness	0.018	0.196	0.845	0.272	3.349	0.001
PA (Gastrocnemius lateralis)	-0.121	-1.553	0.124	0.005	0.076	0.939
PA (Gastrocnemius medialis)	-0.145	-1.790	0.077	-0.107	-1.624	0.106
Grip strength
Anterior radial muscle thickness	0.051	0.471	0.639	-0.035	-0.405	0.686
Anterior ulnar muscle thickness	0.537	4.965	0.001	0.283	3.167	0.002
Posterior tibial muscle thickness	-0.025	-0.204	0.838	0.015	0.139	0.890
Posterior fibula muscle thickness	-0.030	-0.251	0.803	0.148	1.574	0.118
PA (Gastrocnemius lateralis)	0.038	0.381	0.704	0.069	0.878	0.381
PA (Gastrocnemius medialis)	-0.124	-1.187	0.239	0.046	0.597	0.552
Gait speed
Anterior radial muscle thickness	0.099	0.760	0.449	-0.081	-0.959	0.339
Anterior ulnar muscle thickness	-0.095	-0.723	0.472	0.213	2.391	0.018
Posterior tibial muscle thickness	-0.139	-0.935	0.352	0.006	0.059	0.953
Posterior fibula muscle thickness	0.060	0.413	0.681	0.140	1.491	0.138
PA (Gastrocnemius lateralis)	-0.045	-0.374	0.709	0.045	0.572	0.568
PA (Gastrocnemius medialis)	-0.099	-0.785	0.435	0.187	2.449	0.015
SPPB
Anterior radial muscle thickness	0.059	0.492	0.624	0.020	0.215	0.830
Anterior ulnar muscle thickness	0.012	0.097	0.923	0.004	0.043	0.965
Posterior tibial muscle thickness	-0.028	-0.209	0.835	0.133	1.169	0.244
Posterior fibula muscle thickness	0.034	0.259	0.796	-0.058	-0.570	0.570
PA (Gastrocnemius lateralis)	0.044	0.396	0.693	0.034	0.401	0.689
PA (Gastrocnemius medialis)	-0.081	-0.701	0.485	0.179	2.171	0.031

Notes: Adjustment for age and BMI, β standardized coefficient.

Abbreviations: RASM, relative appendicular skeletal muscle mass; PA, pennation angle; SPPB, short physical performance battery.