Design and implementation of a full-body kinesiological assessment protocol during functional tasks in children with Cerebral Palsy (GMFM Level III)

Abstract

Cerebral palsy (CP) is caused by early brain injuries that affect movement. Its evaluation depends on the severity and relies on tools such as the Gross Motor Function Classification System (GMFCS), which analyzes trunk control, and Human Movement Analysis (HMA), which quantifies motor function through kinesiological variables. Currently, there are no full-body measurement methods for CP, so clinical scales are used instead. Motor changes and joint ranges still need to be quantified. The goal was to design and implement a full-body kinesiological assessment protocol using a motion analysis system to evaluate motor performance in individuals with CP during the execution of functional tasks.

A kinesiological assessment protocol was designed following the seven-stage process of Erdmar and Sandor (2014), identifying functional tasks based on the GMFCS and variables such as joint ranges and trajectories. The “Plug-in Gait” models from Nexus-VICON were modified for both lower and upper limbs. Four children with bilateral spastic cerebral palsy classified as GMFCS level III from the INR-LGII (average age: 10 ± 5 years) participated after signing informed consent. Anthropometric measurements were taken, and reflective markers were placed. Activities included gait with a force platform (FP), sit-to-stand (StS), and upper limb functional tasks. Data were analyzed using Nexus-VICON and Visual 3D.

Average joint range of motion (ROM) and ground reaction force (GRF) were obtained. During gait, ROM in the X-plane was: hip 43 degrees, knee 42 degrees, ankle 8 degrees; and in the Y-plane: hip 3 degrees, knee 20 degrees, ankle 5 degrees.

In the sit-to-stand (StS) task, X-plane ROM reached: hip 65 degrees, knee 53 degrees, ankle 12 degrees; and Y-plane ROM: hip 5 degrees, pelvis 2 degrees, knee 12 degrees, ankle 4 degrees. For upper body tasks: Can lifting: shoulder ROM in the X-plane was 46 degrees, elbow 81 degrees; wrist ROM in the Y-plane was 3 degrees; Resistance band exercise: shoulder ROM in the X-plane was 23 degrees, elbow 99 degrees, wrist 2 degrees; Pinch task: shoulder ROM in the X-plane was 51 degrees, elbow 81 degrees; Button pressing: shoulder ROM in the X-plane was 20 degrees and in the Y-plane 98 degrees. Ground reaction force was measured using the force platform (FP), normalized by body weight. The maximum ground reaction forces were: Gait: 8 kg in both legs; StS: 43 kg in the left leg and 65 kg in the right leg, indicating greater average strength in the right leg.

It is concluded that joint range of motion and ground reaction force are consistent metrics for validating the protocol. The averages help identify functional patterns, highlighting greater joint involvement during the sit-to-stand (StS) task and greater strength in the right leg, suggesting biomechanical compensations. These results support the protocol's use in clinical settings.