**2. Changes in hemiplegic gait**

*Assistive and Rehabilitation Engineering*

most used tests:

differs from those of healthy people concerning different points like performance and organization. The main anomalies observed in this population are an alteration of spatiotemporal and kinematic parameters. Therapeutic management and

Medical care of gait disturbance in stroke patients use different treatments based on clinical evaluation and functional evaluation. Evaluation of the stroke patient's gait aims at characterizing the motor performance to provide clinicians with

information on the patient's organizational or performance status and to allow them

Gait Assessment (FGA) and the 3D instrumented Gait Analysis (3D-GA).

over a 30 m [8, 9] walkway to determine the average walk speed.

functional mobility, walking balance, and postural transitions.

limitations due to the size of the environment and its duration.

The walk of the patient in the hospital environment, equipped with these reflective markers, may be not representative of his/her locomotion in everyday life: the distance is too short, the ground is horizontal without asperities, and the trajectory is very often rectilinear. When using a treadmill, the start and stop phases are delicate for the patient's balance. Also, finding a device providing information

An embedded wearable motion analysis system uses a set of sensors worn on the body of the person to measure locomotion parameters. The system must be energy

In the same way, after applying these different therapeutic approaches, the evaluation allows the therapist to determine the effectiveness of the latter in relation to the fixed objective. Among the different methods for evaluating gait, the most commonly used to know the patient's organization during walking are the Functional

There are different types of functional tests that can be used in varying scenarios to evaluate the locomotion of hemiparetic patients. Here, we just list some of the

• The 5- or 10-m walking test: timed walk on a set distance (5 or 10 m) with spontaneous or maximum speed. With this test, the mean of speed, cadence,

• The 6-minute walk test: assesses the maximum distance walked during 6 minutes

• The Timed Up and GO test: the patient is asked to rise from a chair, walk 3 m, turn, walk back to the chair and sit down. It can be used to assess walking speed,

The FGAs are performed under the situations close to those of the patient's daily life but do not provide all the parameters characterizing walking. They do not allow observing the evolution of all the parameters and also limit the number of measurable parameters; their measurement is generally not precise because it is too qualitative. The 3D-GA provides the clinician with all the quantitative information on the state of organization of the musculoskeletal system during the execution of the locomotor task by means of the kinematic, kinetic, and spatiotemporal parameters of the gait. A 3D-GA system uses the absolute three-dimensional location of the object moving relative to a system reference also fixed. It can be typically of optoelectronic type (Motion Analysis, Vicon, Optitrack, Qualisys, Saga, Codamotion, etc.). The patient, equipped with reflective markers located on anatomical points, walks in an environment equipped with optoelectronic cameras that record the displacement of the markers, of a platform of force to detect the events of the gait cycle. A complex post processing on the recorded information extracts the locomotor parameters. This test can only be performed in a hospital environment with

prospective follow-up take into account these two points.

to consider the most appropriate treatment options.

and step length could be determined.

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on walking is a necessity.

#### **2.1 Changes in spatiotemporal parameters of the gait cycle**

The gait cycle, normal or pathologic, is divided into eight sub-phases: initial contact, loading response, midstance, terminal stance, pre-swing, initial swing, mid swing, and late swing [10, 11]. If the full cycle is normalized to 100%, then the stance phase (between initial contact (IC) event and final contact (FC) event) represents 60% and the swing phase 40%. This normalization makes it possible to compare the results of different studies or different populations.

The spatiotemporal parameters are often used to describe and characterize the locomotion [3, 10]. **Figure 1** illustrates the definition of the spatial parameters like step width, step length, and stride length.

The following are the temporal parameters:


If, for a healthy subject, the durations of the sub-phases in a cycle are symmetrical for the left and the right sides, it is not the case for a stroke patient. In that case, the duration of the stance phase and its percentage of the gait cycle decrease for the affected lower limb compared to the healthy subject [12–16]. Moreover, the duration of the single support phase of the paretic side is decreased compared to the healthy side. The spontaneous gait speed can be considered as a significant element that traduces patients' ability to walk [10]. Similarly, different studies [17, 18]

**Figure 1.** *Spatial parameters.*

showed that the cadence of the stroke patients is decreased compared to those of the healthy subject whatever their gait speed.
