Further to Liam's success with his toys is that he is even more motivated to learn to sit upright unsupported. This is also somewhat unexpected. After many months of castings on both of his legs, we expected Liam to be further behind schedule in this milestone. In this, he is proving to be an overachiever and in a good way!
And speaking of milestones, we have accepted that Liam will likely learn to walk without ever crawling due to the restrictions in his elbow and shoulder joints. However, he is rolling around all over the place. So we now have a large play mat for him to roll all over to his heart's content. He loves it!
As a last note regarding toys, he particularly favors any that he can easily get a grip with his hands as pictured
below. His favorite is a rubber ball with holes all around it so he can hold on to it and move with it. It provides an incredible stretch to his fingers, hands, wrists, elbows and shoulders that he does all by himself! So, to any others out there who know children with arthrogryposis in the upper extremities: this toy should be high on your list!