| Intervention group N 44 | Control group N 35 | |
| CVAI < 3.5 at start of study | 32 (73%) | 27 (77%) |
| CVAI > 3.5 at start of study | 12 (27%) | 8 (23%) |
| Gender | 19 female (43%) 25 male (57%) | 17 female (49%) 18 male (51%) |
| Birth weight mean | 3576 gram | 3451 gram |
| Birth length mean | 51.3 cm | 50.0 cm |
| Gestation week | 39.9 | 39.2 |
| Favorite side | 25 (57%) | 18 (51%) |
| Imbalance in muscle function in the lateral flexors of the neck | 15 (34%) | 11 (31%) |
| Low SOMP-I score | 15 (34%) | 12 (34%) |
| Low amount of tummy time when awake, 0 - 2 times a day | 20 (45%) | 18 (51%) |