0 MONTHS
- Turns head side to side in prone position
- Bobs head but stays erect in upright position
- Kicks feet alternately in supine position
- Bears small fraction of weight on feet in upright position
- Props on extended arms
- Rolls to supine from prone position
6 MONTHS
- Sits with trunk erect in a chair
- Reaches in prone position
- Assumes quadruped in prone position
- Sits unsupported for 30 seconds
- Rolls to prone position from supine position
- Crawls