INTRODUCTION
Cerebral palsy (CP) is primarily a disorder of movement and posture. It is a group of non-progressive, but often changing, motor impairment syndromes secondary to lesions or anomalies of the brain arising in the early stages of its development [1]. It is referred to as a static encephalopathy because, despite the constant primary lesion, the clinical pattern of presentation may change over time due to growth and developmental spasticity, and central nervous system maturation [2]. Spasticity primarily impairs voluntary movements but can occasionally be beneficial for weight bearing or support. Extensor tone in the limbs aids in standing and maintains muscle bulk and bone density [3]. Most of the children with CP have difficulty while walking independently because of impaired postural control, abnormal muscle tone and pathological muscular coordination [4]. Different types of walking aids and assistive devices are often prescribed for assisting and providing the stability necessary for ambulation. Assisted walking may not only improve the growing child mobility but also make a difference in their ability to explore the environment and interact with their peers [5]. However, extremely high heart rates and slow walking speed were recorded in the children with CP during ambulation with walking aids [6].
Walkers are frequently prescribed to children with CP to provide additional stability required for ambulation. Traditionally, an anterior walker has been used as a walking aid. However, a child using an anterior walker tends to lean forward while pushing the walker. The Posterior Walker is sparely used and it is designed to be positioned behind the child because it facilitates a more upright posture [6]. However, it can also be very difficult to collapse and adjust. In the past, studies have been conducted on the comparison of the anterior walker and posterior walkers. Most of the studies have focused on gait analysis, energy consumption, and kinetics and kinematics of the upper extremity in children with spastic diplegic cerebral palsy, however, the information about the use of these walkers is heterogeneous and controversial [7,8]. In systematic reviews, researchers have compared the use of anterior and posterior walkers by children with cerebral palsy to determine which type of walker is preferable. Poole et al. (2017) has studied the outcomes including velocity, pelvic tilt, hip flexion, knee flexion, step length, stride length, cadence, double stance time, oxygen cost and participant/parental preference and found heterogeneity and low quality of existing evidence that prevented the recommendation of one walker type [7]. Tao et al. (2020) in another review found similar gait parameters and upper extremity functions in both types of walkers, but they concluded that the posterior walker was preferable due to its relatively low oxygen cost [8]. Furthermore, there have been conflicting results in the literature regarding gait parameters and energy expenditure between anterior and posterior walkers. The novel approach of designing walkers for maintaining an upright posture, reducing energy expenditure, and improving gait parameters in people with cerebral palsy has not been thoroughly investigated. An attempt was made in this study to design and develop a novel walker to address issues of height provision, assist the user in walking with proper posture, and improve biomechanical efficiency. Therefore, this study intends to establish the biomechanical efficacy of the novel walker and compare it with the standard posterior walker. This research will help to plan appropriate ambulatory devices for CP children, reducing energy expenditure and improving gait parameters.
MATERIALS AND METHODS
2.1 Subject characteristics
- Sample size: Thirty subjects with spastic diplegic CP with age range 4-10 years
- Inclusion criteria: The subjects with poor trunk control with good hand grip power. They were able to understand the command and able to walk independently with a walker. None had undergone orthopaedic or neurosurgical intervention before being enrolled in this study.
- Exclusion criteria: The subjects with poor neck and sitting balance or with profound developmental retardation, multiple disabilities and COVID positive test findings during screening were excluded.
- Ethical approval and Consent: The study was approved by the Institutional Ethics Board of SVNIRTAR, DA/MPO/08/2019 on March 03, 2020. All patients signed an informed consent form and were informed about the purpose of the study with their parents. The CTRI registry number is CTRI/2022/01/039642.
2.2 Description of Walkers
Basically, the posterior walker is designed to be used by individuals who can fully support their own weight and are able to take steps. Posterior walker design neglects the rapid growth and typical activities of young children. In contrast, the novel walker designed and developed in this study has taken the basic functional requirements of children with spastic diplegic CP into consideration. This has been a modified approach ensuring the advantages of different variants of walkers available in the global market. The features of the walkers used for comparison in this study are elaborated below.
Fig. 1 Walkers used (a) Posterior and (b) Novel in the study
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Posterior Walker |
Novel Walker |
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2.3 Study tools and Parameters
A 10-meter walk test [9] was used for measuring gait parameters. The energy expenditure was measured by using Physiological Cost Index (PCI) by using an oxymeter. Parameters such as step length, stride length, velocity, cadence, width of walking base were measured by using stop watch and measuring tape.
2.4 Study procedure
Following the initial screening, assessment, and evaluation, demographic data such as age, gender, height, and weight were collected. The patients were divided into two groups at random. Group A (n=15) subjects were tested with the posterior walker, while Group B (n=15) subjects were tested with the novel walker. The posterior walker was prefabricated whereas the novel walker was height adjusted to the subject's needs. The handle height was positioned at elbow 15 degree flexion for the individual subject. The training on their use during gait was provided for one month prior to the evaluation so that they were familiar with both types of walkers. The subjects were told to walk on a 10-meter walk test paper using a modified walker or a posterior walker (Fig. 2). An oxymeter was used to measure energy expenditure before and after each experiment. A stop watch and measuring tape were also used to measure step length, stride length, velocity, cadence, and the width of the walking base. The standard COVID protocol was maintained during data collection.
2.5. Data analysis and statistics
All data were managed in a Microsoft Excel spread sheet. The statistical analyses were conducted using SPSS v. 21.0 (SPSS Inc, Chicago, Illinios). Independent student t-test was performed to analyze the difference between posterior and novel walker. The tests were applied at 95% confidence interval and a p-value less than or equal to 0.05 was considered statistically significant.