Ageing joints can cause you some difficulty. You may experience pain and mobility issues from overuse syndrome, especially the upper limbs (shoulder, arm, wrist and hand).
This effects at least 50 percent of the SCI population and is more common and severe in older individuals and increases with time since injury. It is caused by overuse, wheelchair pushing, lifting to help with pressure releases and the use of crutches to help walking in individuals with incomplete SCI.
To minimise joint issues gentle exercise and keeping weight down are recommended. It may also be worth considering joint and limb preservation strategies even in the initial phases of rehabilitation training like using a transfer board to reduce the strain on your arms.