In this first picture, D is encouraging Josiah to utilize his arms for trunk support. Josiah's chest is being supported by her hands. It is hoped that he will start to demonstrate good "weight bearing" on his arms. This accomplishment is a critical next step. As you can see from this picture, Josiah has gained a lot of head control in the past few months. He is able to hold his own head up for extended periods of time now.
Josiah leans on D, arms supported, in an effort to "learn what it feels like to sit." Josiah's trunk is still quite floppy. However, with a little arm support and place to rest his head - he's starting to figure it out. Look at the little grin on his face :)
Here, he has to utilize more of his own muscles to keep his trunk from becoming floppy (he's not actively leaning on D). D continues to support him via his arms. As he uses his neck muscles to support his head, he has to work much harder.
Josiah gets tired as the session continues. Here, he uses a boppy pillow for support while he rests his body. He uses the binky (aka, pacifier) which is another tool used to increase muscle tone. "The pacifier strengthens oral motor control and helps develop the muscles needed for drinking, eating solid foods, and talking." (http://www.downsyndromedallas.org/New%20Parent%20Guide/print%20docs/Feeding.pdf). You can see here that he is able to hold his 'binky' in his mouth. We even observed him take the binky out of his mouth and successfully return it to his mouth :)
As Josiah nears the end of the session, he is exhausted. He has worked hard. We resort to the tripod toy - it is the one toy that usually prevents a meltdown (especially at the end of the session). Josiah is content to play with the dangling toys. This, too, is still work but disguised as play. Josiah continues to strengthen his arms and stamina, each time he reaches for a hanging toy.
D is packing up to leave. I can the exhaustion in Josiah's eyes. He has worked hard. He deserves a break <3.