Mariano Serrao1, Giorgia Chini2, Marco Iosa3, Carlo Casali4, Giovanni Morone5, Carmela Conte6, Fabiano Bini7, Franco Marinozzi8, Gianluca Coppola9, Francesco Pierelli10, Francesco Draicchio11, Alberto Ranavolo12. 1. Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Via Faggiana 34, 40100 Latina, Italy; Rehabilitation Centre Policlinico Italia, Piazza del Campidano 6, 00162 Rome, Italy. Electronic address: mariano.serrao@uniroma1.it. 2. Biolab3, Department of Engineering, Roma TRE University, Via Vito Volterra 62, 00149 Roma, Italy. 3. Clinical Laboratory of Experimental Neurorehabilitation, IRCCS Santa Lucia Foundation, Via Ardeatina 306, 00179 Rome, Italy. Electronic address: m.iosa@hsantalucia.it. 4. Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Via Faggiana 34, 40100 Latina, Italy. Electronic address: carlo.casali@uniroma1.it. 5. Clinical Laboratory of Experimental Neurorehabilitation, IRCCS Santa Lucia Foundation, Via Ardeatina 306, 00179 Rome, Italy. Electronic address: g.morone@hsantalucia.it. 6. Fondazione Don Gnocchi Foundation, Milan, Italy. Electronic address: conte_carmela@libero.it. 7. Department of Mechanical and Aerospace Engineering, "Sapienza" University of Rome, Via Eudossiana 18, 00184 Rome, Italy. Electronic address: fabiano.bini@uniroma1.it. 8. Department of Mechanical and Aerospace Engineering, "Sapienza" University of Rome, Via Eudossiana 18, 00184 Rome, Italy. Electronic address: franco.marinozzi@uniroma1.it. 9. G.B. Bietti Foundation-IRCCS, Department of Neurophysiology of Vision and Neurophthalmology, Via Livenza 3, 00198 Rome, Italy. 10. Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Via Faggiana 34, 40100 Latina, Italy. Electronic address: francesco.pierelli@uniroma1.it. 11. INAIL, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Via Fontana Candida 1, 00040 Monte Porzio Catone, Italy. Electronic address: f.draicchio@inail.it. 12. INAIL, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Via Fontana Candida 1, 00040 Monte Porzio Catone, Italy. Electronic address: a.ranavolo@inail.it.
Abstract
BACKGROUND: The harmony of the human gait was recently found to be related to the golden ratio value (ϕ). The ratio between the duration of the stance and that of the swing phases of a gait cycle was in fact found to be close to ϕ, which implies that, because of the fractal property of autosimilarity of that number, the gait ratios stride/stance, stance/swing, swing/double support, were not significantly different from one another. We studied a group of patients with cerebellar ataxia to investigate how the differences between their gait ratios and the golden ratio are related to efficiency and stability of their gait, assessed by energy expenditure and stride-to-stride variability, respectively. METHODS: The gait of 28 patients who were affected by degenerative cerebellar ataxia and of 28 healthy controls was studied using a stereophotogrammetric system. The above mentioned gait ratios, the energy expenditure estimated using the pelvis reconstructed method and the gait variability in terms of the stride length were computed, and their relationships were analyzed. Matching procedures have also been used to avoid multicollinearity biases. FINDINGS: The gait ratio values of the patients were farther from the controls (and hence from ϕ), even in speed matched conditions (P=0.011, Cohen's D=0.76), but not when the variability and energy expenditure were matched between the two groups (Cohen's D=0.49). In patients with cerebellar ataxia, the farther the stance-swing ratio was from ϕ, the larger the total mechanical work (R2adj=0.64). Further, a significant positive correlation was observed between the difference of the gait ratio from the golden ratio and the severity of the disease (R=0.421, P=0.026). INTERPRETATION: Harmony of gait appears to be a benchmark of physiological gait leading to physiological energy recovery and gait reliability. Neurorehabilitation of patients with ataxia might benefit from the restoration of harmony of their locomotor patterns.
BACKGROUND: The harmony of the human gait was recently found to be related to the golden ratio value (ϕ). The ratio between the duration of the stance and that of the swing phases of a gait cycle was in fact found to be close to ϕ, which implies that, because of the fractal property of autosimilarity of that number, the gait ratios stride/stance, stance/swing, swing/double support, were not significantly different from one another. We studied a group of patients with cerebellar ataxia to investigate how the differences between their gait ratios and the golden ratio are related to efficiency and stability of their gait, assessed by energy expenditure and stride-to-stride variability, respectively. METHODS: The gait of 28 patients who were affected by degenerative cerebellar ataxia and of 28 healthy controls was studied using a stereophotogrammetric system. The above mentioned gait ratios, the energy expenditure estimated using the pelvis reconstructed method and the gait variability in terms of the stride length were computed, and their relationships were analyzed. Matching procedures have also been used to avoid multicollinearity biases. FINDINGS: The gait ratio values of the patients were farther from the controls (and hence from ϕ), even in speed matched conditions (P=0.011, Cohen's D=0.76), but not when the variability and energy expenditure were matched between the two groups (Cohen's D=0.49). In patients with cerebellar ataxia, the farther the stance-swing ratio was from ϕ, the larger the total mechanical work (R2adj=0.64). Further, a significant positive correlation was observed between the difference of the gait ratio from the golden ratio and the severity of the disease (R=0.421, P=0.026). INTERPRETATION: Harmony of gait appears to be a benchmark of physiological gait leading to physiological energy recovery and gait reliability. Neurorehabilitation of patients with ataxia might benefit from the restoration of harmony of their locomotor patterns.