Gait pattern of severely disabled hemiparetic subjects on a new controlled gait trainer as compared to assisted treadmill walking with partial body weight support.

OBJECTIVES: To investigate to what extent and with how much therapeutic effort nonambulatory stroke patients could train a gait-like movement on a newly developed, machine-supported gait trainer. DESIGN: Open study comparing the movement on the gait trainer with assisted walking on the treadmill. SETTING: Motion analysis laboratory of a rehabilitation centre. SUBJECTS: Fourteen chronic, nonambulatory hemiparetic patients. INTERVENTION: Complex gait analysis while training on the gait trainer and while walking on the treadmill. MAIN OUTCOME MEASURES: Gait kinematics, kinesiological EMG of several lower limb muscles and the required assistance. RESULTS: Patients could train a gait-like movement on the gait trainer, characterized kinematically by a perfect symmetry, larger hip extension during stance, less knee flexion and less ankle plantar flexion during swing as compared to treadmill walking (p <0.01). The pattern and amount of activation of relevant weight-bearing muscles was comparable with an even larger activation of the M. biceps femoris on the gait trainer (p <0.01). The tibialis anterior muscle of the nonaffected side, however, was less activated during swing (p <0.01). Two therapists assisted walking on the treadmill while only one therapist was necessary to help with weight shifting on the new device. CONCLUSION: The newly developed gait trainer offered severely disabled hemiparetic subjects the possibility of training a gait-like, highly symmetrical movement with a favourable facilitation of relevant anti-gravity muscles. At the same time, the effort required of the therapists was reduced.

Development of an advanced mechanised gait trainer, controlling movement of the centre of mass, for restoring gait in non-ambulant subjects.

The study aimed at further development of a mechanised gait trainer which would allow non-ambulant people to practice a gait-like motion repeatedly. To simulate normal gait, discrete stance and swing phases, lasting 60% and 40% of the gait cycle respectively, and the control of the movement of the centre of mass were required. A complex gear system provided the gait-like movement of two foot plates with a ratio of 60% to 40% between the stance and swing phases. A controlled propulsion system adjusted its output according to patient's efforts. Two eccenters on the central gear controlled phase-adjusted the vertical and horizontal position of the centre of mass. The patterns of sagittal lower limb joint kinematics and of muscle activation of a normal subject were similar when using the mechanised trainer and when walking on a treadmill. A non-ambulatory hemiparetic subject required little help from one therapist on the gait trainer, while two therapists supported treadmill walking. Gait movements on the trainer were highly symmetrical, impact-free, and less spastic. The weight-bearing muscles were activated in a similar fashion during both conditions. The vertical displacement of the centre of mass was bi-instead of mono-phasic during each gait cycle on the new device. In conclusion, the gait trainer allowed wheelchair-bound subjects the repetitive practice of a gait-like movement without overstraining therapists.

Asymmetry of gait initiation in hemiparetic stroke subjects.

OBJECTIVE: To investigate symmetry of gait initiation in healthy and hemiparetic subjects. DESIGN: Survey. SETTING: Kinematic laboratory affiliated with a hospital-based department of rehabilitation. PATIENTS OR OTHER PARTICIPANTS: Ten healthy and 14 hemiparetic stroke subjects starting five times with their right and left leg, respectively. MAIN OUTCOME MEASURES: Duration of defined periods, step length, center of pressure, and center of mass were recorded and calculated using two triaxial force plates, contact switches, and a video camera system. RESULTS: Healthy subjects displayed a high degree of independence of kinetic and kinematic parameters of the starting limb. Hemiparetic patients showed differences with respect to the starting limb: when starting with the nonaffected leg, the swing period and step length was shorter and the center of pressure displayed a more marked medio-lateral sway with no corresponding initial movement of the center of mass; when starting with the affected leg the movement pattern of the center of pressure and center of mass was comparable to that of normal subjects. CONCLUSIONS: The trajectories of the center of pressure and center of mass and the symmetry parameters are in accordance with a higher degree of uncertainty when starting with the non-affected limb in hemiparetic subjects.

[Development of a gait trainer with regulated servo-drive for rehabilitation of locomotor disabled patients]. / Entwicklung eines Gangtrainers mit geregeltem Servoantrieb zur Rehabilitation gehunfähiger Patienten.

The aim of the present study was to develop a new gait trainer for the rehabilitation of non-ambulatory patients. For the simulation of the gait phase, we used a commercially available fitness trainer (Fast Track) with two foot plates moving in an alternating fashion and connected to a servo-controlled propulsion system providing the necessary support for the movement depending on the patient's impairment level. To compensate deficient equilibrium reflexes, the patient was suspended in a harness capable of supporting some of his/her weight. Video analysis of gait and the kinesiological EMG were used to assess the pattern of movement and the corresponding muscle activity, which were then evaluated in healthy subjects, spinal cord injured and stroke patients and compared with walking on the flat or on a treadmill. Walking on the gait trainer was characterised by a symmetrical, sinusoidal movement of lower amplitude than in normal gait. The EMG showed a low activity of the tibialis anterior muscle, while the antigravity muscles were clearly activated by the gait trainer during the stance phase. In summary, the new gait trainer generates a symmetrical gait-like movement, promoting weight acceptance in the stance phase, which is important for the restoration of walking ability.

Gait initiation, development of a measuring device for use in a clinical environment.

Gait initiation is a part of daily mobility, its restoration thus plays a major role in the rehabilitation of hemiparetic patients that have a higher risk of falling. This study presents a clinically applicable system for the analysis of gait initiation of healthy persons and hemiparetic patients. For this purpose we have analysed the triaxial ground reaction forces yielding the displacement of the centre of pressure (CP) and, with a two-fold integration of ground reaction forces, the centre of mass (CM). These are descriptive parameters of the dynamics and symmetry of gait initiation that could predict the risk of falling. Hemiparetic patients showed a distinct behaviour when starting either with their affected or non-affected limb. Future applications include individual assessment of patients with gait disabilities and validation of physiotherapy strategies.