In many cases, damage to the central nervous system caused by a stroke leads to paralysis of the muscles responsible for dorsiflexion of the foot. For patients with weakness of dorsiflexion of the foot for whom conventional therapy is not effective, Otto Bock offers a completely new type of therapy: The ActiGait® neurostimulator reactivates fully or partially paralyzed muscles via the corresponding intact nerve.
The movement impulse is transmitted by a small electronic chip that can be implanted into a small incision in the skin of the thigh in a day surgery procedure or during stationary care. A cable leads to the nervus peronaeus communis above the hollow of the knee and connects to it using an especially developed cuff electrode. After this contact point, the natural signal transmission path is used. The muscle receives the impulse telling it to contract, and raises the foot. The implanted chip is supplied with energy by an external control unit worn on the belt. A pressure sensor worn under the foot supplies the control unit with information regarding the gait phase. The data are evaluated by the control unit and muscle stimulation is matched to the gait pattern. The goals of stimulation are to expand the activity radius, improve independence, maintain or reestablish the personal activity level of the patient, reduce spasticity, and maintain joint mobility.
Scientific studies prove that ActiGait® results in a significant increase in walking speed and safety. In addition, perception of the environment and social interaction improve because the patient has to pay less attention to walking. The gain in mobility improves personal well-being and performance. The training effect for the knee and hip promotes an additional improvement of walking ability. The function control unit is easy for the patient to handle. It can even be used with limited arm functionality.
1. Weakness of dorsiflexion of the foot as a result of hemiplegia after a stroke.
2. Passive ankle movement of at least 30° on the affected side.
3. The ability to stand upright with both heels on the floor while the hip and knee are in a neutral position.
4. The ability to walk 20 m in less than 2 minutes with or without an aid, but without the help of other persons.
5. Maximum waking speed below 1.2m/sec.
6. Positive reaction to surface stimulation, so that dorsiflexion results due to a muscle contraction; a gait improvement must be noticeable.