Part I - State of the art
1. Contextualizing
Neurological disorders are one of the major causes of mortality and disability worldwide (GBD 2016 Neurology Collaborators, 2019) and are frequently associated with varying degrees of sensory and motor problems. Balance control impairment is often present in patients suffering from these disorders, highly impacting daily life. Having an intact balance control is required for maintaining postural stability and for enabling safe mobility related daily activities, that include weight shifting and changing position while performing manual tasks, walking and climbing stairs, among others (Mancini & Horak, 2010). Patients with balance disorders present a higher fall risk leading to limited activity capacity and restrictions in participation in daily life situations, which result in social isolation and physical inactivity and its underlying consequences (Kwakkel et al., 2023; Nonnekes et al., 2018). For this reason, it is vital to recognize and assess neurological disorders of balance and posture in clinical settings.
2. Balance Control System
Balance control is achieved by integration and coordination of different body systems, involving the vestibular and vision system for gaze stabilization, sensory (proprioception) and motor systems for postural stabilization. Information from all these systems is processed and interpreted by the central nervous system so an adequate response is given for the appropriated muscle activation and body movement (Mancini & Horak, 2010).
3. When Balancing Gets Tough
Within neurological disorders it is possible to observe serious alterations in matters of peripheral and central nervous system that have a serious impact on postural control, such as somatic-sensorial impairments, including changes in proprioception resulting from slowed transmission of somatic sensory impulses or changes in mechanoreceptors, alterations in the integration of sensory inputs, changes in reflexes, muscle strength, neuromuscular function, and muscle tonus, among others (Nonnekes et al., 2018). For instance, post-stroke patients who suffer from impaired balance and postural control, frequently show an increased sway during quiet stance and asymmetrical lower limb weight distribution, this asymmetrical stance is believed to be resultant from muscle weakness and proprioception deficits (De Nunzio et al., 2014). Balance dysfunction is also very common in Parkinson’s Disease, being highly disabling and resulting in an increased predisposition for falling. Changes in muscle tone and proprioception disrupt sense of position, which results in displacement of the body center of mass over the base of support, consequently patients with Parkinson’s Disease show higher velocity and frequency of body sway (Ferrazzoli et al., 2015). Furthermore, traumatic brain injuries, which are acquired acute neurological disorders can also lead to balance dysfunction. It is believed that the areas of the brain disrupted from this type of injury are responsible for maintaining postural control, leading to a failure in integration and organization of sensory information by the central nervous system (Guskiewicz et al., 2001). In multiple sclerosis, up to two thirds of patients show incapacitating balance problems. It is now known that a slowed transmission of somatic sensory impulses may have an important effect on the postural stability of these patients (Inojosa et al., 2020).
Interestingly, many patients are not fully aware of changes in balance and posture, which is frequently one of the earliest signs of a neurological disorder (Nonnekes et al., 2018). This emphasizes the importance of a rigorous and objective balance and posture assessment as part of clinical examination.
4. Balance Assessment - Posturography
The aim of clinical balance and posture assessment is to, firstly, identify if there is in fact a balance problem, and finally to determine and differentiate the underlying cause, so the intervention is as effective as it can be. This means that balance and posture assessment should provide objective and quantitative measurements so it can be translated into simple, nonetheless vital, information for diagnosis and treatment planning (Mancini & Horak, 2010; Visser et al., 2008).
Posturography is seen as the gold standard for postural control assessment, capable of showing sensory and motor contributions for postural and balance control, deviations from center of gravity and changes in limits of stability. The most common posturographic measurement in balance assessment is the center of pressure (COP) displacement, enabling the quantifying of postural sway (Duarte & Freitas, 2010). For instances, a study from Inojosa et al. in 2020 showed that balance alterations in multiple sclerosis patients could be detected with static posturography before being perceivable by the physician, both the ellipse area and the average sway speed could sense differences between healthy subjects and multiple sclerosis patients with normal cerebellar function and Romberg Test (Inojosa et al., 2020). Ferrazzoli et al. came to a similar conclusion, where balance dysfunction in Parkinsonian patients could be detected before patients complain using posturography platforms (Ferrazzoli et al., 2015). In stroke patients, studies have shown greater ellipse area and a higher tendency to sway, specifically in the mediolateral plane (Hugues et al., 2017; Lee et al., 1997). Furthermore, De Nunzio et al. concluded that the COP index of asymmetry (a COP resulting parameter of COP displacement in the mediolateral plane) is a valid measure of paretic limb loading during stroke recovery (De Nunzio et al., 2014). Whereas in Parkinson patients, posturography analysis shows smaller limits of stability and higher mediolateral sway, partially explained by the proprioceptive dysfunction responsible for impairing adaptation to a changing base of support and for reducing perception of trunk and surface orientation (Ferrazzoli et al., 2015). Another interesting study was conducted by Silsby et al. showed that objective assessment of balance using posturography may work as a biomarker of Intravenous Immunoglobulin efficacy in patients with Chronic Inflammatory Demyelinating Polyradiculoneuropathy (Silsby et al., 2022).
Here we present just a small number of studies that use posturography for balance assessment, within neurologic dysfunction context. For instance, Parkinson’s Disease is a very complex disease, with multiple systems being affected, posturography has been investigated in order to better understand it’s role on the objective evaluation of deficits in balance and postural control as on the development of rehabilitation programs (Ferrazzoli et al., 2015; Terra et al., 2020).
Do you have doubts about this topic? Or need advice about balance system?
Schedule a 15 minute talk with me if you want to know more about this subject.
Ana Souto
Meet Ana, a physiotherapist with a master's degree in human physiology, currently specializing in neurobiology. Her professional journey has led her to gain extensive expertise in both neurology and sports physiotherapy.
Ana currently serves as the clinical specialist at PhysioSensing, a cutting-edge Balance Assessment and training device. Leveraging her strong foundation in scientific research and evidence-based practices, Ana creates customized assessment and training plans. Her approach is firmly rooted in the latest scientific findings, ensuring that PhysioSensing users receive the most effective and up-to-date care.
In addition to her role in designing tailored programs, Ana plays a pivotal role in guiding new clients through the learning process of using PhysioSensing. She also provides advanced training and support to existing customers seeking to further deepen their clinical practice knowledge and stay on top of the latest scientific advancements.
5. References
De Nunzio, A. M., Zucchella, C., Spicciato, F., Tortola, P., Vecchione, C., Pierelli, F., & Bartolo, M. (2014). Biofeedback rehabilitation of posture and weightbearing distribution in stroke: A center of foot pressure analysis. Functional Neurology, 29(2), 127–134.
Duarte, M., & Freitas, S. M. S. F. (2010). Revision of posturography based on force plate for balance evaluation. Revista Brasileira De Fisioterapia (Sao Carlos (Sao Paulo, Brazil)), 14(3), 183–192.
Ferrazzoli, D., Fasano, A., Maestri, R., Bera, R., Palamara, G., Ghilardi, M. F., Pezzoli, G., & Frazzitta, G. (2015). Balance Dysfunction in Parkinson’s Disease: The Role of Posturography in Developing a Rehabilitation Program. Parkinson’s Disease, 2015, 1–10. https://doi.org/10.1155/2015/520128
GBD 2016 Neurology Collaborators. (2019). Global, regional, and national burden of neurological disorders, 1990-2016: A systematic analysis for the Global Burden of Disease Study 2016. The Lancet. Neurology, 18(5), 459–480. https://doi.org/10.1016/S1474-4422(18)30499-X
Guskiewicz, K. M., Ross, S. E., & Marshall, S. W. (2001). Postural Stability and Neuropsychological Deficits After Concussion in Collegiate Athletes. Journal of Athletic Training, 36(3), 263–273.
Hugues, A., Di Marco, J., Janiaud, P., Xue, Y., Pires, J., Khademi, H., Cucherat, M., Bonan, I., Gueyffier, F., & Rode, G. (2017). Efficiency of physical therapy on postural imbalance after stroke: Study protocol for a systematic review and meta-analysis. BMJ Open, 7(1), e013348. https://doi.org/10.1136/bmjopen-2016-013348
Inojosa, H., Schriefer, D., Klöditz, A., Trentzsch, K., & Ziemssen, T. (2020). Balance Testing in Multiple Sclerosis-Improving Neurological Assessment With Static Posturography? Frontiers in Neurology, 11, 135. https://doi.org/10.3389/fneur.2020.00135
Kwakkel, G., Stinear, C., Essers, B., Munoz-Novoa, M., Branscheidt, M., Cabanas-Valdés, R., Lakičević, S., Lampropoulou, S., Luft, A. R., Marque, P., Moore, S. A., Solomon, J. M., Swinnen, E., Turolla, A., Alt Murphy, M., & Verheyden, G. (2023). Motor rehabilitation after stroke: European Stroke Organisation (ESO) consensus-based definition and guiding framework. European Stroke Journal, 23969873231191304. https://doi.org/10.1177/23969873231191304
Lee, M. Y., Wong, M. K., Tang, F. T., Cheng, P. T., & Lin, P. S. (1997). Comparison of balance responses and motor patterns during sit-to-stand task with functional mobility in stroke patients. American Journal of Physical Medicine & Rehabilitation, 76(5), 401–410. https://doi.org/10.1097/00002060-199709000-00011
Mancini, M., & Horak, F. B. (2010). The relevance of clinical balance assessment tools to differentiate balance deficits. European Journal of Physical and Rehabilitation Medicine, 46(2), 239–248.
Nonnekes, J., Goselink, R. J. M., Růžička, E., Fasano, A., Nutt, J. G., & Bloem, B. R. (2018). Neurological disorders of gait, balance and posture: A sign-based approach. Nature Reviews Neurology, 14(3), 183–189. https://doi.org/10.1038/nrneurol.2017.178
Silsby, M., Yiannikas, C., Ng, K., Kiernan, M. C., Fung, V. S. C., & Vucic, S. (2022). Posturography as a biomarker of intravenous immunoglobulin efficacy in chronic inflammatory demyelinating polyradiculoneuropathy. Muscle & Nerve, 65(1), 43–50. https://doi.org/10.1002/mus.27398
Terra, M. B., Da Silva, R. A., Bueno, M. E. B., Ferraz, H. B., & Smaili, S. M. (2020). Center of pressure-based balance evaluation in individuals with Parkinson’s disease: A reliability study. Physiotherapy Theory and Practice, 36(7), 826–833. https://doi.org/10.1080/09593985.2018.1508261
Visser, J. E., Carpenter, M. G., Van Der Kooij, H., & Bloem, B. R. (2008). The clinical utility of posturography. Clinical Neurophysiology, 119(11), 2424–2436. https://doi.org/10.1016/j.clinph.2008.07.220