International Journal of Environmental Research and Public Health Article Analysis of Gait for Disease Stage in Patients with Parkinson’s Disease Ma Helena Vila *, Rocío Pérez, Irimia Mollinedo and José Ma Cancela Research Group HealthyFit, Institute of Health Research Galicia Sur (IISGS), Hospital University Complex of Pontevedra (CHOP), SERGAS, University of Vigo, 36310 Pontevedra, Spain; [email protected] (R.P.); [email protected] (I.M.); [email protected] (J.M.C.) * Correspondence: [email protected]; Tel.: +34-986-80-20-56 Abstract: Understanding the motor patterns underlying the movement of individuals with Parkin- son’s disease (PD) is fundamental to the effective targeting of non-pharmacological therapies. This study aimed to analyze the gait pattern in relation to the evolutionary stages I–II and III–IV according to the Hoehn and Yahr (H&Y) scale in individuals affected by PD. The study was conducted with the participation of 37 PD patients with a mean age of 70.09 ± 9.53 years, and of whom 48.64% were women. The inclusion criteria were (1) to be diagnosed with PD; (2) to be in an evolutionary stage of the disease between I and IV: and (3) to be able to walk independently and without any assistance. Kinematic and spatial-temporal parameters of the gait were analyzed. The results showed differences in speed of movement, cadence, stride length, support duration, swing duration, step width, walking cycle duration, and double support time between the stages analyzed. These results confirmed the differences in PD gait pattern between stages I–II and III–IV. Different behaviors of the same variable were recorded depending on whether the right or left side was affected by PD. Keywords: locomotion disorder; cadence; gait oscillation; speed of movement; neurodegenera- tive disease Citation: Vila, M.H.; Pérez, R.; Mollinedo, I.; Cancela, J.M. Analysis of Gait for Disease Stage in Patients with Parkinson’s Disease. Int. J. 1. Introduction Environ. Res. Public Health 2021, 18, Parkinson’s disease (PD) is one of the most common age-related neurodegenerative 720. https://doi.org/10.3390/ diseases [1]. Progressive gait dysfunction is one of the primary motor symptoms in PD [2]. ijerph18020720 It is usually characterized by a reduction in step length and walking speed, and an increase in step time and cadence [3]. Disturbances in gait and posture are often resistant to drug Received: 14 December 2020 treatment, deteriorate as the disease progresses, increase the likelihood of falls, and result in Accepted: 13 January 2021 higher rates of hospitalization and mortality, thus having a negative impact on the patients’ Published: 15 January 2021 quality of life [4]. The difficulty of walking within normal parameters is undoubtedly one of the greatest challenges faced by PD patients. Publisher’s Note: MDPI stays neutral The Hoehn and Yahr (H&Y) scale is the most widely used instrument for establishing with regard to jurisdictional claims in published maps and institutional affil- the degree of PD progression by simple staging [5,6]. It is used as the “gold standard” for iations. checking other scales. According to the application of the H&Y scale, the most advanced stages of the disease lead to the worst quality of walking movements in PD patients, but limited information is available regarding the evolution of spatial-temporal and kinematic parameters, and the degree to which they contribute to this deterioration of the walking pattern. Therefore, further studies are needed in order to identify how to improve both the Copyright: © 2021 by the authors. extent and quality of PD patients’ motor skills. Licensee MDPI, Basel, Switzerland. The analysis of walking patterns in healthy individuals has made it possible to obtain This article is an open access article reference values for each variable (e.g., speed, cadence, stride length), which help to distributed under the terms and conditions of the Creative Commons diagnose possible alterations in walking [7]. Movement disorders are differentially present Attribution (CC BY) license (https:// throughout the development of various pathologies and may well reflect the underlying creativecommons.org/licenses/by/ pattern of neurodegeneration [1,4]. It would be desirable to have the same values for 4.0/). pathologies that present characteristic patterns of walking, such as Parkinson’s disease Int. J. Environ. Res. Public Health 2021, 18, 720. https://doi.org/10.3390/ijerph18020720 https://www.mdpi.com/journal/ijerph Int. J. Environ. Res. Public Health 2021, 18, 720 2 of 10 (stiff gait), as these help in the early identification of pathologies that generate alterations in the gait pattern and cycle, if they have not already been diagnosed. It is very important to establish which tools will help in the early identification of the different motor changes that occur during the evolution of the disease. From this point of view, it is necessary to make a detailed motor examination in order to determine as precisely as possible where and when it would be most advisable to intervene (from a motor point of view) throughout the course of the disease. Although instrumented motion analysis systems have been used for decades, their application has been mainly restricted to a laboratory environment. Today, with the technological advances in the analysis of movement in PD, new instruments are being presented for analysis, among which portable sensor technology [8], robotic rehabilitation [9], inertial sensors [10,11], and dynamometric or force platforms are notable [12]. There are numerous studies that analyze gait patterns in PD [13,14], but the number de- creases when spatial-temporal and kinematic variables are analysed together [9,15]. There are several studies that reported differentiated symptoms in stages I–II and III–IV [5,6], but no research has been found that analyses and describes the evolution of spatial-temporal and kinematic variables in relation to the stage of PD progression and how this affects gait. Therefore, there is a need to identify changes in the pattern of walking as a function of the stage of the disease by assessing kinematic and spatial-temporal parameters. This will enable health and fitness professionals and physiotherapists to design and imple- ment customized exercise programs based on the specific needs of PD patients. Early identification is a key factor in establishing effective therapy and reducing costs in health and social care. For this reason, this study aimed to analyze the walking pattern (kinetic and spatial-temporal parameters) according to the evolutionary stage (I–II vs. III–IV) as specified by the Hoehn and Yahr (H&Y) scale in patients diagnosed with PD. 2. Materials and Methods This is a primary study of a descriptive type (cross-sectional), in which a health- related population problem was analyzed; the study group comprised PD patients at different evolutionary stages of the disease. Thirty-seven PD patients aged between 61 and 87 years, with a mean age of 70.06 ± 9.53 years, participated in the study, of whom 18 were women. The inclusion criteria were being diagnosed with PD, the evolutionary stage of the disease being between I and IV according to the H&Y scale (a higher score indicates more severe impairment and disability), and being able to walk independently and without any assistance. 2.1. Subjects The participants of the study were selected through a research proposal addressed to the Parkinson’s Association of the province of Pontevedra, specifically in the towns of Bueu and Villagarcia, by means of a collaborative framework agreement established between the association and the University of Vigo for research purposes. Participants volunteered to participate in the study, and those who met the inclusion criteria outlined above were selected. All participants were informed of the objectives of the study and signed the informed consent form. The study was approved by the ethics committee of the Regional Ministry of Health (code: CEIC: 2017/343) prior to the start of the research. All the procedures were undertaken in accordance with the ethical standards of the Helsinki Declaration of 1975, as revised in 2008, and Good Clinical Practice [16]. The sample size was calculated taking into account the systematic review of Parkin- son’s Disease gait assessment using wearable motion sensors [17], with the location of the sensors on the lower back. For the calculation, the program G*power was used to estimate a proportion from an infinite total population (N), which maximizes the sample size. A confidence/safety level (1-alpha) of 95%, an accuracy (d) of 7%, and a ratio of 5% were chosen to maximize the sample size. Based on these data, the sample size (n) should be 37 subjects. Int. J. Environ. Res. Public Health 2021, 18, 720 3 of 10 2.2. Instruments In terms of anthropometric measurements, the height (cm) and weight (kg) of the participants were recorded with them being barefoot and wearing light clothing. The subjects’ body mass index (BMI) was calculated using the formula: weight/height2 (kg/m2). The measuring devices used were a Tanita TBF300 scale (TANITA Corporation, Tokyo, Japan) with an accuracy of 0.1 kg and a Handac stadiometer (Holtain Ltd., Crosswell, UK) with an accuracy of 1.0 mm. The anthropometric measurements were taken following the ISAK (International Working Group of Kinanthropometry) protocols [18]. A dynamometric corridor was used to evaluate the subjects’ gait by means of the pressure platforms E.P.S.-R1 of the LORAN-Engineering Company (LORAN-Engineering Company, Bologna, Italy) [12]. This corridor is composed of three platforms with 2304 sen- sors on an active surface of 2400 cm2, with a thickness of 7 mm, which facilitates the dynamic bipodal analysis of the patients. The kinetic variables evaluated by the dynamo- metric platforms in the gait corridor were as follows: average foot-support area (cm2), maximum foot pressure (Kpa), and average foot pressure (Kpa).