Natália Mariana Silva Luna

The influence of anthropometric factors on postural balance: the relationship between body composition and posturographic measurements in young adults

OBJECTIVE: The aim of the present study was to evaluate the influence of anthropometric characteristics and gender on postural balance in adults. One hundred individuals were examined (50 males, 50 females; age range 20-40 years). METHODS: The following body composition measurements were collected (using bone densitometry measurements): fat percentage (% fat), tissue (g), fat (g), lean mass (g), bone mineral content (g), and bone mineral density (g/cm2). In addition, the following anthropometric measurements were collected: body mass (kg), height (cm), length of the trunk-cephalic region (cm), length of the lower limbs (cm) and length of the upper limbs (cm). The following indices were calculated: body mass index (kg/m2), waist-hip ratio and the support base (cm2). Also, a postural balance test was performed using posturography variables with open and closed eyes. RESULTS: The analysis revealed poor correlations between postural balance and the anthropometric variables. A multiple linear regression analysis demonstrated that the whole group (female and male) height explained 12% of the medial-lateral displacement, 10% of the speed of oscillation, and 11% of the displacement area. The length of the trunk-cephalic length explained 6% of the displacement in the anteroposterior direction. With eyes closed, the support base and height explained 18% of the medial displacement, and the lateral height explained 10% of the displacement speed and 5% of the scroll area. CONCLUSION: Measured using posturography, the postural balance was only slightly influenced by the anthropometric variables, both with open and closed eyes. Height was the anthropometric variable that most influenced postural balance, both in the whole group and separately for each gender. Postural balance was more influenced by anthropometric factors in males than females.

Validation of GDI, GPS and GVS for use in parkinson's disease through evaluation of effects of subthalamic deep brain stimulation and levodopa

The Gait Deviation Index (GDI), Gait Profile Score (GPS) and Gait Variable Scores (GVSs) have been proposed as measures of gait quality and validated for use with children with cerebral palsy. The aim of this study was to extend this validation to people with Parkinsons disease by evaluating the effects of subthalamic deep brain stimulation and levodopa on gait. 16 participants had their gait evaluated with stimulation, medication or a combination of both. The Unified Parkinsons Disease Rating Scale (UPDRS) showed statistically significant differences in agreement with previous studies. The GPS and GDI showed similar treatment effects as did GVS for hip and knee flexion/extension, as assessed with Cohens d where medium or large. Overall the results suggest that these gait indices are sensitive to treatment in this group of patients and that their use in groups other than children with cerebral palsy is valid.

Relation between the Sensory and Anthropometric Variables in the Quiet Standing Postural Control: Is the Inverted Pendulum Important for the Static Balance Control?

The aim of this study was to evaluate the relation between the sensory and anthropometric variables in the quiet standing. Methods. One hundred individuals (50 men, 50 women; 20–40 years old) participated in this study. For all participants, the body composition (fat tissue, lean mass, bone mineral content, and bone mineral density) and body mass, height, trunk-head length, lower limb length, and upper limb length were measured. The center of pressure was measured during the quiet standing posture, the eyes opened and closed with a force platform. Correlation and regression analysis were run to analyze the relation among body composition, anthropometric data, and postural sway. Results. The correlation analysis showed low relation between postural sway and anthropometric variables. The multiple linear regression analyses showed that the height explained 12% of the mediolateral displacement and 11% of the center of pressure area. The length of the trunk head explained 6% of displacement in the anteroposterior postural sway. During eyes closed condition, the support basis and height explained 18% of mediolateral postural sway. Conclusion. The postural control depends on body composition and dimension. This relation is mediated by the sensory information. The height was the anthropometric variable that most influenced the postural sway.

Isokinetic analysis of ankle and ground reaction forces in runners and triathletes

OBJECTIVE: To analyze and compare the vertical component of ground reaction forces and isokinetic muscle parameters for plantar flexion and dorsiflexion of the ankle between long-distance runners, triathletes, and non-athletes. METHODS: Seventy-five males with a mean age of 30.26 (±6.5) years were divided into three groups: a triathlete group (n = 26), a long-distance runner group (n = 23), and a non-athlete control group. The kinetic parameters were measured during running using a force platform, and the isokinetic parameters were measured using an isokinetic dynamometer. RESULTS: The non-athlete control group and the triathlete group exhibited smaller vertical forces, a greater ground contact time, and a greater application of force during maximum vertical acceleration than the long-distance runner group. The total work (180°/s) was greater in eccentric dorsiflexion and concentric plantar flexion for the non-athlete control group and the triathlete group than the long-distance runner group. The peak torque (60°/s) was greater in eccentric plantar flexion and concentric dorsiflexion for the control group than the athlete groups. CONCLUSIONS: The athlete groups exhibited less muscle strength and resistance than the control group, and the triathletes exhibited less impact and better endurance performance than the runners.

Muscle strength, postural balance, and cognition are associated with braking time during driving in older adults.

BACKGROUND Despite the well-known declines in driving performance with advancing age, there is little understanding of the specific factors that predict changes in key determinants such as braking time. OBJECTIVES The aims of this study were to determine the extent to which age, muscle strength, cognition and postural balance are associated with braking performance in middle-aged and older adults. METHODS Male and female middle-aged adults (n=62, age=39.3±7.1years) and older adults (n=102, age=70.4±5.8years) were evaluated for braking performance, as well as in several motor and cognitive performance tasks. The motor evaluation included isokinetic ankle plantar flexor muscle strength, handgrip strength, and postural balance with and without a cognitive task. The cognitive assessment included the Mini Mental State Examination. Braking performance was measured using a driving simulator. RESULTS Older adults exhibited 17% slower braking time, lower strength, and poorer performance in the postural balance (p<0.001). For both older and middle-aged adults, significant correlates of braking time included performance in the postural balance tests, muscle strength, and cognitive function. However, after full model adjustment, only postural balance and cognitive function were significantly associated. CONCLUSION Muscle strength, postural balance, and cognition are associated with braking time, and may affect the safety of and driving performance in older adults. These findings may help to inform specific targeted interventions that could preserve driving performance during aging.

Association between handgrip strength, balance, and knee flexion/extension strength in older adults

The objective of the study was to examine the association between handgrip strength (HGS), knee flexion and extension strength, and static and dynamic balance in older women. One hundred and ten women with a mean age of 67.4±5.9 years were assessed for dynamic postural balance using the Time Up & Go Test (TUG) with and without cognitive tasks. Semi-static balance was assessed by means of a force platform; knee flexor and extensor muscle strength was calculated using an isokinetic dynamometer; and HGS using a hand held dynamometer. Weaker HGS was significantly correlated with worse performance in dynamic postural balance, as well as performance with TUG with and without cognitive tasks; however, there was no correlation between HGS and static balance. There was a moderate positive correlation between knee flexion/extension strength and HGS. This suggests that HGS could be used as a proxy indicator of overall strength capacity for clinical screening among older women.

Treadmill training in Parkinson's patients after deep brain stimulation: Effects on gait kinematic

OBJECTIVE The purpose of this study was to evaluate the effect of treadmill training with body weight support on gait kinematics parameters in patients with PD using DBS. DESIGN Twelve patients completed the protocols (age: 60.9±10.6 years; disease duration: 20±7 years; and time since DBS surgery: 20±4 months). The same set of patients underwent two trainings protocols and four gait analyses (before and after each training). They received eight weeks of treadmill training without body weight support (16 sessions) in conjunction with physiotherapy program followed by six weeks of wash out period, followed by eight weeks of body-weight-supported treadmill training in conjunction with a same physiotherapy program. The Gait Kinematic Analysis involved eight infrared cameras that detected 19 reflective spherical markers attached in limb lower of patients. Statistical analysis used the Wilcoxon test (p≤0.05). RESULTS Both the training no showed significant differences in linear variables. As the angular variables, only training with support showed significant increase of ranges of motion: pelvis tilt, obliquity and rotation amplitude; hip adduction-abduction and rotation amplitude; percentage of peak flexion in swing phase; foot progression amplitude. CONCLUSION The body weight supported treadmill training may promote increase of mobility of lower limbs during gait and it could be a targeted intervention for PD patients treated with DBS.

The effects of motor adaptation on ankle isokinetic assessments in older drivers

OBJECTIVES: This study sought to analyze the extent of motor adaptation in ankle plantar flexors and dorsiflexors among older drivers during clinical isokinetic testing. METHODS: One hundred older adults (70.4±5.7 years) participated in two bilateral ankle plantar flexor and dorsiflexor isokinetic assessments at 30°/sec. Peak torque (PTQ), PTQ adjusted for body weight (PTQ/BW), and total work (TW) were analyzed. RESULTS: On the dominant side, PTQ/BW and TW were significantly greater for the second plantar flexion test than were those for the first such test (p<0.001), whereas PTQ, PTQ/BW, and TW (p<0.001) were significantly greater for the second dorsiflexion test than were those for the first such test. On the non-dominant side, plantar flexion PTQ and TW were significantly lower for the second test than were those for the first test (p<0.001). CONCLUSION: Older drivers demonstrated better performance with the dominant limb on the second test. The low variability in test execution showed the existence of a motor adaptation effect for the tested movements, despite the short recovery period between the assessments.

ANÁLISE DE TEMPO DE ACELERAÇÃO DO TORNOZELO EM CORREDORES DE LONGA DISTÂNCIA E TRIATLETAS

INTRODUCAO: O tempo adequado de reacao muscular e essencial para proteger as articulacoes contra lesoes durante atividades esportivas. Este fenomeno de tempo de aceleracao tem sido investigado por meio de metodologias como experimentos com trampolim e eletromiografia. No entanto, a analise isocinetica e um metodo de avaliacao que e mais dinâmico e mostra comportamento mais proximo da funcionalidade do esporte. Corrida de longa distância e triatlo tem altas taxas de lesao de membros inferiores, particularmente em relacao a articulacao do tornozelo. O objetivo deste estudo foi avaliar e comparar os tempos de aceleracao e desaceleracao isocinetica do dorsiflexor e da musculatura flexora plantar do tornozelo em corredores de longa distância, triatletas e individuos nao atleticos. METODO: A amostra incluiu 75 individuos (homens com idade entre 18-42 anos), divididos em tres grupos: triatletas, corredores de longa distância e grupo controle. Os individuos foram testados bilateralmente em um dinamometro isocinetico. Os modos de avaliacao utilizados foram: 1. concentricos/excentricos para flexao plantar e dorsiflexao; 2. excentricos/concentricos para flexao plantar e dorsiflexao. A analise estatistica utilizou analise de variância e teste post hoc de Tukey; Testes post hoc de Kruskal-Wallis e Muller-Dunn e testes Qui-quadrado. RESULTADOS: O tempo de aceleracao durante a contracao excentrica foi estatisticamente diferente apenas entre o grupo controle e o grupo corredor de longa distância: os controles apresentaram aceleracao mais rapida. CONCLUSAO: Este resultado pode indicar uma deficiencia no controle sensorial do seu motor durante a atividade concentrica dos dorsiflexores.

The effects of foot morphology and anthropometry on unipodal postural control

The maintenance of posture is a constant challenge for the body, as it requires rapid and accurate responses to unforeseen disturbances, which are needed to prevent falls and maintain balance. The purpose of the present study was to compare different types of plantar arch in relation to postural balance, and analyze the relationships between variations the plantar arch and anthropometric characteristics of the feet with unipedal static balance. We evaluated 100 men and women between the ages of 20 and 40 years old, to determine anthropometry and posturography with a force platform. There was a weak correlation between plantar arches and anthropometric measurements and postural balance, except for the length of the male foot, which showed a correlation between increased size and poorer static balance. We conclude that the type of plantar arch does not influence postural balance, and of the anthropometric factors, only foot length was related to postural balance.