def METHOD_NAME(
    index_one, torque, rod_one_director_collection, rod_one_external_torques
):
    start_idx = index_one[0]
    end_idx = index_one[-1]
    rod_one_external_torques[..., start_idx] += 0.5 * _batch_matvec(
        rod_one_director_collection[..., start_idx : start_idx + 1], torque
    ).reshape(3)
    rod_one_external_torques[..., end_idx] -= 0.5 * _batch_matvec(
        rod_one_director_collection[..., end_idx : end_idx + 1], torque
    ).reshape(3)