Dear Spandanphysio,
I too agree with you, the pattern you described seems more like associated reaction. You described the pattern of upper limb, is the child having any abnormal reactions in lower limbs too. As far as associated reactions are concerned, they occur due to the effort made by less effected part during activity. In NDT approach, associated reactions can be reduced by grading the activity to reduce the effort. Weight bearing specifically mobile weight bearing can be done on effected limb, positioning it in TIP. Working on movement components required to achieve task also reduces the associated reaction.
As you said child's trunk is very low tone, this is something goes with history of premature birth having low tone proximally and abnormal high tone distally. Developing tone in trunk and increasing proximal stability might help to reduce effort and thus abnormal patterns in this child. Rolling ( the only thing child can do independently), facilitated through upper limbs keeping them fully extended above the shoulder could give the child experience of mobile weight bearing on shoulder while shoulder in TIP, and increase tone in trunk. I try approximation/ compressions on proximal joints (shoulder and hips) to get trunk and pelvic floor muscles active in some children with similar condition depending on how child is reacting.
In transitions, has child learnt to come up on all fours from side lying position . I try with my patients, facing difficulty to come up to kneeling, to assume four point kneeling against wedge. They are encouraged to get down on wedge while leaning upper trunk forward with slope so that they are resting on their elbows and than come back again to bear weight on palms on wedge. From there, they can extend less effected arm to pick object above the shoulder, keeping effected arm on wedge first and gradually taking that arm off the wedge to assume high kneeling gradually.
In sitting to reach out for an object can be made easier by working on balancing reactions in supine, prone, sitting on ball first. This will enable child to learn weight shifting on pelvis and trunk extension, required to use hands freely in sitting. Reaching out could be made graded by, sitting on lap/ bench with feet supported, reaching in midline first below the shoulder and gradually increase the level of object higher and side ways to reach out of the base of support. Child can learn to lean forward and come back to sit up, helpful to increase truncal tone. Mobile weight bearing on effected arm can be used together keeping arm in pattern of TIP, while child is moving forward to reach for an object.
I tried to share my experiences with you. I will be happy if we could stay in touch regarding this case and share some more experiences together. Regards.