Arm Muscle Strength in Children with Bilateral Spastic CP

Figures & data

Table 1. Description of measurements with the myometer. Position and stabilization of the subject, placement of the myometer’s resistance to the body movement and point for measurement of lever arm.

Muscle group	Position	Stabilization	Resistance	Lever arm from
shoulder abductors	Sitting, Shoulder abducted 90°, elbow flexed opposite hand in knee		Humerus distally	Acromion
elbow extensors	Supine, shoulder adducted, elbow flexed 90°. Forearm in neutral	Humerus	Forearm distally	Lateral humeral epicondyl
elbow flexors	Supine, shoulder adducted, elbow flexed 90°. Forearm in supination	Shoulder	Forearm distally	Lateral humeral epicondyl
wrist dorsiflexors	Supine, shoulder adducted, elbow extended. Forearm in pronation, fingers extended	Forearm	Dorsum of hand	Lateral styloid

Table 2. Description of participants, mean (SD).

	MACS		Comparison MACS I and II
	I n = 26	II n = 13	P=
Age	11.1 (2.3)	11.6 (2.1)	.580
Weight	36.2 (10.7)	37.5 (11.2)	.740
Height	140 (14.5)	142 (12.9)	.770
Hand dominance right / left	20 / 5	6 / 5

Figure 1. Box plot for four muscle groups in the arms, divided by MACS level. Data in % of predicted value, boxes indicating median and 25–75 percentile, and circles show observations outside 10 or 90 percentile. Dashed line indicating predicted normal.

Table 3. Mean muscle strength in four muscle groups in the arms and grip strength. Data divided by MACS level and split by hand dominance. Values presented as % of predicted normal, mean (SD), and grip strength in Newton. Difference between non-dominant and dominant side calculated as a ratio.

	MACS level				Comparison MACS I and II	Ratio nondom/dom
Muscle group	n=	I %	n=	II %	P=	I	II
Shoulder abductors
all	50	80.0 (27.8)	24	65.7 (20.6)	.028
dom	24	80.8 (28.5)	11	65.3 (20.2)	.116	0.99	0.92
non dom	24	79.9 (28.8)	11	60.0 (17.5)	.042
Elbow extensors
all	50	103.7 (31.6)	26	99.0 (31.2)	.536
dom	24	103.7 (32.4)	11	106.4 (33.4)	.822	1.02	0.94
non dom	24	105.3 (32.3)	11	99.7 (31.9)	.636
Elbow flexors
all	50	99.6 (24.7)	26	91.4 (28.1)	.196
dom	24	101.4 (25.9)	11	97.1 (30.9)	.669	0.98	0.91
non dom	24	99.3 (24.3)	11	88.7 (29.8)	.275
Wrist dorsiflexors
all	50	101.5 (33.0)	25	70.3 (31.6)	<.001
dom	24	106.0 (37.3)	11	79.1 (29.3)	.043	0.91	0.77
non dom	24	96.2 (29.3)	10	58.7 (30.1)	.002
Grip strength		Newton		Newton
dom		208.4 (107.9)		251.3 (180)		0.96	0.86
non dom		200.7 (107.6)		216.0 (147.5)

Table 4. Correlations between muscle strength and age, weight and height.

	age			weight			height
	N	corr	Sig.	N	corr	Sig.	N	corr	Sig.
Shoulder abductors
dom	37	.384*	.019	37	.336*	.042	35	.593**	<.001
non dom	37	.351*	.033	37	.301	.070	35	.492**	.003
Elbow extensors
dom	38	.349*	.032	38	.575**	<.001	35	.501**	.002
non dom	38	.339*	.037	38	.478**	.002	35	.472**	.004
Elbow flexors
dom	38	.182	.273	38	.197	.235	35	.417*	.013
non dom	38	.135	.421	38	.176	.290	35	.388*	.021
Wrist extensors
dom	38	−.528**	.001	38	−.449**	.005	35	−.340*	.046
non dom	37	−.484**	.002	37	−.375*	.022	34	−.323	.062
Grip strength
dom	15	.883**	<.001	15	.509	.052	15	.850**	<.001
non dom	15	.869**	<.001	15	.530*	.042	15	.847**	<.001

* Correlation is significant at the 0.05 level (2-tailed).

** Correlation is significant at the 0.01 level (2-tailed).