September 9, 2013
Lokomat® Training with Spinal Cord Injured ASIA A Patients
Markus Wirz, PT
Spinal Cord Injury Center, Balgrist University Hospital, Zürich, Switzerland
Patient groups: neurological patients – spinal cord injuries of traumatic and non-traumatic origin
Clinical experience: the physiotherapy department at the Spinal Cord Injury Center is responsible for performing Lokomat training with stationary and ambulatory paraplegic patients.
The Spinal Cord Injury Center at Balgrist University Hospital has been successfully using the Lokomat for the past 10 years for the rehabilitation of spinal cord injury patients with incomplete motor function loss. The Lokomat is mainly used to treat patients presenting with severely impaired walking ability, e.g. ASIA B/C incomplete spinal cord injuries, during the initial rehabilitation phase.
At Balgrist University Hospital we usually do not use the Lokomat to treat patients with complete paraplegia (ASIA A). A return to ambulation is improbable and therefore not the goal of rehabilitation. This prognosis is constantly reassessed based on the clinical neurological and electrophysiological examination. If there is no evidence of a significant motor improvement, the objective will be to enable these new wheelchair users to be as independent as possible in daily life. The focus will be put on wheelchair handling and transfers as well as upper extremity strengthening exercises. There is another reason why physicians and therapists are reluctant to use the Lokomat with this specific patient population. ASIA A patients should not be given false expectations of ever being able to walk again. Putting a patient into the Lokomat could be misleading, that is why physicians and therapists alike must correctly inform the patients as to what they can realistically expect from training with the Lokomat.
Lokomat® Training Goals with ASIA A Patients
An attempt was made to use the Lokomat with complete paraplegic patients to train the mobility of passive structures of the musculoskeletal system.
In principle, Lokomat training is also possible with severely paralyzed ASIA A patients. For safety reasons the following conditions must however be fulfilled:
- Definition of treatment goals;
- Prior training with a tilt table to evaluate cardiovascular stability in the upright position;
- Prior assessment of bone stability (e.g. bone density measurement) in patients with chronic spinal cord injury who are mainly mobile in a wheelchair.
On top of the mentioned conditions, we must also exclude patients who do not have enough mobility in the lower extremity joints to achieve a physiological gait pattern.
In addition to the medical prescription and physical prerequisites, the following considerations must also be taken into account in ASIA A patients. The absence or impairment of sensory function below the neurological level of lesion implies that the patient’s skin must be carefully inspected at the contact sites with the Lokomat after each training session.
The lower extremities of chronic ASIA A patients have hardly been subjected to load stimuli over a long period of time. Passive and active structures such as bones, muscles or ligaments thus lose their weight-bearing capacity. If bone density measurement is inconclusive, the patient cannot train on the Lokomat. For the same reason the first training session at the hospital is limited to 20 minutes. If there are no signs of skin irritation or excessive strain, the training duration can then be increased progressively, depending on treatment success.
Training Parameters for ASIA A Patients
At first, training frequency is determined, usually a short treatment series consisting of 9 training units taking place 1-2/week for about 4-6 weeks. Patient setup is performed according to the Hocoma training standards.
The initial parameters for spastic patients are set as follows:
The range of motion (ROM) of the hip and knee joints is reduced depending on the patient’s spasticity pattern, and hip joint movement is shifted towards flexion. To do so, the patient must be totally supported (lifted), otherwise his feet would scrape the treadmill due to the reduced joint mobility. The parameters are adjusted to the individual gait pattern and the patient is lowered onto the treadmill. Experience has however also shown that walking “in the air” actually triggers spasticity compared to touching the ground. In such cases avoid completely supporting the patient if possible.
The walking speed depends on the patient’s state of health. A slow gait tempo tends to inhibit spasticity, whereas a high tempo will increase it. Empirical values range from 1.8 to 2.5 km/h.
The body weight support depends on the physiological gait pattern. The patient should stand as upright as possible, his knee joints should be stretched during stance phase and his feet should not scrape the treadmill during swing phase.
The training goals are evaluated together with the patient after each session and at the end of the treatment series. L-STIFF assessment before and after each training is best suited for that purpose. Additionally, it is recommended to test everyday life movements that are most strongly affected by spasticity, e.g. transfers.
The Lokomat meets the requirements for gait training of severely paralyzed patients with complete spinal cord injuries. At Balgrist University Hospital the Lokomat is only used on a trial basis with ASIA A patients. At the same time and based on the therapists’ assessment, the patients receive joint mobility training and cardiovascular training. During training with the Lokomat, the absence of sensory function as well as the reduced weight-bearing capacity of the lower extremities must be taken into account. The training parameters are continuously monitored and adjusted to meet therapy goals. An evaluation takes place after each training session and at the end of the treatment series.