biballism means ballism that affects both sides of the body.
Etymology
From bi- + ballism.
noun
- Ballism that affects both sides of the body.“Ballism is a dramatic proximal ballistic flinging movement (see Chapter 21) that most commonly affects the limbs on one side of the body (hemiballism), but involvement in both legs (paraballism) or both sides of the body (biballism) has been reported.”