Importance of muscle strength to maintain mobility, but not to maintain postural balance in older women: Cross-sectional study.

BACKGROUND: Acknowledging the relationship between postural control and muscle strength in lower limbs is important to find persons with high fall risk and to design fall prevention exercise programs. OBJECTIVE: To investigate the connection between knee muscle strength, semi-static postural balance, and functional mobility in irregularly active older women. METHODS: One hundred and ten older women aged 60 to 85 years underwent a semi-static postural balance test in a force and functional mobility measured by Timed Up & Go (TUG) with and without Cognitive Tasks (CT). Muscle strength of the knee was assessed by isokinetic dynamometry at 60°/s. RESULTS: A negative correlation between the functional mobility (TUG with and without CT) and the muscular strength of the knee was observed. Regarding semi-static balance, there was a low negative correlation with peak torque corrected for body weight of the extensors with the following variables with eyes open: Mean Velocity Dominant limb (D) (r = -0.19; p = 0.03); and anteroposterior range Non-Dominant limb (ND) (r = -0.19; p = 0.04); with eyes closed: mediolateral range ND limb (r = -0.21; p = 0.02) and Mean Velocity ND limb (r = -0.18; p = 0.05). CONCLUSIONS: This study found that better functional mobility was associated with greater muscle strength in the knee in elderly women. There were weak negative correlations between knee extensor strength and some measures of semi-static postural balance, suggesting that different motor control actions are required to maintain semi-static balance and mobility. In the case of semi-static balance, a lower level of muscle response is required than in functional mobility.

The decline in postural balance has a negative impact on the performance of functional tasks in individuals with Parkinson's Disease.

INTRODUCTION: An accurate assessment of balance problems is critical for decreasing the risk of falling in patients with Parkinson's Disease (PD). Reliable diagnostic tools such as Computerized Dynamic Posturography (CDP) are not feasible for the clinical setting. Therefore, the present study's aim was to assess the correlation between the clinical Balance Evaluation Systems Test (BESTest) and CDP. METHODS: 20 male older adults with Parkinson's Disease (PD) were included in this study. Participants first executed the Sit-To-Stand (STS), Step/Quick turn (SQT), and Step Up and Over (SUO) tests on a Balance Master® force platform, followed by a clinical balance evaluation using the BESTest. RESULTS: Four outcomes of the CDP were negatively correlated with one or more BESTest domains or total BESTest score: STS sway velocity was negatively correlated with the anticipatory postural adjustment (p = 0.02) and sensory orientation (p = 0.01) domains. SQT turn time was negatively correlated with biomechanical restriction (for turns to the left, p = 0.01, and right, p = 0.03, respectively), postural response (p = 0.01, p = 0.01), dynamic balance during gait (p = 0.007, p = 0.001), and total score (p = 0.02, p = 0.01). Step over time to the right in SUP was negatively correlated with the limits of the stability domain (p = 0.002) and total BESTest score (p = 0.020). SUO impact index was negatively correlated with the anticipatory postural adjustment domain (p = 0.01). CONCLUSION: This study shows that several BESTest domains are significantly correlated with CDP outcomes, demonstrating that the BESTest can be used as a more clinically feasible alternative for computerized posturography, without loss of information.

Fall prediction in a quiet standing balance test via machine learning: Is it possible?

The elderly population is growing rapidly in the world and falls are becoming a big problem for society. Currently, clinical assessments of gait and posture include functional evaluations, objective, and subjective scales. They are considered the gold standard to indicate optimal mobility and performance individually, but their sensitivity and specificity are not good enough to predict who is at higher risk of falling. An innovative approach for fall prediction is the machine learning. Machine learning is a computer-science area that uses statistics and optimization methods in a large amount of data to make outcome predictions. Thus, to assess the performance of machine learning algorithms in classify participants by age, number of falls and falls frequency based on features extracted from a public database of stabilometric assessments. 163 participants (116 women and 47 men) between 18 and 85 years old, 44.0 to 75.9 kg mass, 140.0 to 189.8 cm tall, and 17.2 to 31.9 kg/m2 body mass index. Six different machine learning algorithms were tested for this classification, which included Logistic Regression, Linear Discriminant Analysis, K Nearest-neighbours, Decision Tree Classifier, Gaussian Naive Bayes and C-Support Vector Classification. The machine learning algorithms were applied in this database which has sociocultural, demographic, and health status information about participants. All algorithm models were able to classify the participants into young or old, but our main goal was not achieved, no model identified participants at high risk of falling. Our conclusion corroborates other works in the biomechanics field, arguing the static posturography, probably due to the low daily living activities specificity, does not have the desired effects in predicting the risk of falling. Further studies should focus on dynamic posturography to assess the risk of falls.

Postural control of prolonged standing in people with Parkinson's disease.

People with Parkinson's disease (pwPD) have reduced adaptability to postural control during prolonged standing compared to neurologically healthy individuals (control). Objective. The study aimed to characterize postural changes during prolonged standing and their effect on postural control in pwPD compared to control. We recorded the body sway of the second lumbar vertebra of 23 pwPD and 23 control while they performed prolonged standing (15 min). The number and amplitude of the body sway patterns (shifts, fidgets, and drifts), the root mean square, velocity, and frequency of the body sway were analyzed. The number of shifts in the anterior-posterior (AP) and medial-lateral (ML) directions was greater for the pwPD than the control. In addition, the amplitudes of shifts in the AP direction and fidgets in the AP and ML directions were greater for the pwPD than the control. Our results show that: (1) A larger number of shifts of body sway suggest references positions are frequently changing; (2) Fidgets is a pumping mechanism and can be sensory-demand action to restore mechanoreceptors activity on the foot sole; and (3) No drift changes may suggest there is no slow migration of reference position. We conclude that pwPD exhibits different behavior than healthy ones during prolonged standing, suggesting that prolonged standing could distinguish individuals with Parkinson's disease.

The decline in postural balance has a negative impact on the performance of functional tasks in individuals with Parkinson's Disease

Abstract Introduction An accurate assessment of balance problems is critical for decreasing the risk of falling in patients with Parkinson's Disease (PD). Reliable diagnostic tools such as Computerized Dynamic Posturography (CDP) are not feasible for the clinical setting. Therefore, the present study's aim was to assess the correlation between the clinical Balance Evaluation Systems Test (BESTest) and CDP. Methods 20 male older adults with Parkinson's Disease (PD) were included in this study. Participants first executed the Sit-To-Stand (STS), Step/Quick turn (SQT), and Step Up and Over (SUO) tests on a Balance Master® force platform, followed by a clinical balance evaluation using the BESTest. Results Four outcomes of the CDP were negatively correlated with one or more BESTest domains or total BESTest score: STS sway velocity was negatively correlated with the anticipatory postural adjustment (p = 0.02) and sensory orientation (p = 0.01) domains. SQT turn time was negatively correlated with biomechanical restriction (for turns to the left, p = 0.01, and right, p = 0.03, respectively), postural response (p = 0.01, p = 0.01), dynamic balance during gait (p = 0.007, p = 0.001), and total score (p = 0.02, p = 0.01). Step over time to the right in SUP was negatively correlated with the limits of the stability domain (p = 0.002) and total BESTest score (p = 0.020). SUO impact index was negatively correlated with the anticipatory postural adjustment domain (p = 0.01). Conclusion This study shows that several BESTest domains are significantly correlated with CDP outcomes, demonstrating that the BESTest can be used as a more clinically feasible alternative for computerized posturography, without loss of information.

Sensory Integration for Postural Control in Rheumatoid Arthritis Revealed by Computerized Dynamic Posturography.

Rheumatoid arthritis (RA) is a systemic autoimmune disease that impairs mobility. How does sensory information influence postural responses in people with RA? The aim of this study was to evaluate the postural control of people with RA during a sensory organization test, comparing how sensory information influences postural responses in people with rheumatoid arthritis compared with healthy people. Participants were 28 women with rheumatoid arthritis (RA group) and 16 women without any rheumatoid disease (Control group CG). The Sensory Organization Test (SOT) was performed on a Smart Balance Master® (NeuroCom International, Inc., Clackamas, OR, USA) and center of pressure (COP) was measured. SOT conditions: SOT1 (eyes open, fixed support surface and surround; SOT2) eyes closed, fixed support surface and surround; and SOT5) eyes closed, sway-referenced support surface, and fixed surround. To compare the demographic and clinical aspects between groups, independent t-test or Mann-Whitney's U-test were used. Differences were found between groups. Between SOT conditions, for CG and RA, COP was faster for SOT-5 than SOT-1, while SOT-1 and SOT-2 presented similar COP velocity. For SOT-2 and SOT-5, COP was larger for the RA group. For both groups, SOT-1 presented the smallest COP, and SOT-5 showed the largest COP.

Does dual task merged in a mixed physical exercise protocol impact the mobility under dual task conditions in mild impaired stroke survivors? A feasibility, safety, randomized, and controlled pilot trial.

PURPOSE: To investigate the feasibility, safety, and effects of dual task (DT) in a mixed physical exercise protocol on mobility under DT in stroke survivors. MATERIALS AND METHODS: Twenty-six chronic mild-impaired stroke survivors (age 51.57 ± 12.55; men= 13, women= 13) were randomly assigned into Experimental Group participating in a 15-week mixed (aerobic and resistance exercises performing a cognitive DT condition simultaneously) physical exercise protocol (30 sessions, 2x/week, duration of 60-90 min), and Control Group engaged in the same protocol without DT. Feasibility and outcome measures were assessed before and after the intervention and in a 5-week follow-up. RESULTS: DT physical exercise protocol was viable and safe. This protocol also improved mobility and gait when performed under DT, which was not found in the control group. DT does not influence aerobic resistance, strength, and balance responsiveness. It does not present any improvement in cognition, self-efficacy for falls, and quality of life. CONCLUSION: The results indicate that mixed physical exercise under DT is feasible and safe for mild-impaired stroke survivors. Stroke survivors demonstrate more significant improvement in the mobility performance under DT when submitted to a DT mixed physical exercise protocol than the standard physical exercise intervention. TRIAL REGISTRATION: Brazilian clinical trials registry (RBR-4mvzz6); WHO trial record (U1111-1198-7173)IMPLICATIONS FOR REHABILITATIONDT training can be prescribed by using clear and precise parameters for stroke survivors.Physical Exercise without DT requirements did not improve mobility performing and cognitive tasks simultaneously in stroke survivors.Clinicians are encouraged to incorporate DT requirements into the exercise routines to enhance mobility under DT to mild-moderate stroke survivors.

The variability of isokinetic ankle strength is different in healthy older men and women.

CONTEXT: In the elderly, weak lower limb muscles impair functional tasks' performance. OBJECTIVE: To evaluate the healthy elderly's ankle dorsiflexion and plantarflexion maximum torque and its variability in two sets of 5 RM isokinetics evaluation. METHOD: 50 women (68.0 ± 4.6 years old) and 50 men (72.7 ± 8.5 years old) did two sets of ankle plantar flexor and dorsiflexor isokinetic tests at 30°/s. Peak torque, total work, and coefficient of variation were analyzed. RESULTS: Men did the strongest plantarflexion torque (p < 0.05) and dorsiflexion torque (p < 0.05); their highest peak torque occurred at set 2 (p < 0.05), while the largest plantarflexion torque variability (p < 0.05), dorsiflexion torque variability (p < 0.05), and the largest plantarflexion torque variability occurred at set 1 (p < 0.05). Men did the highest plantarflexion and dorsiflexion total work (p < 0.05) at set 2 (p < 0.05). CONCLUSION: Older men are stronger than older women. The torque variability, in men, was higher during the first set, suggesting an adaptation to the isokinetics evaluation. Clinicians and researchers should consider that different muscles might need different numbers of sets and trials to measure their maximal muscle strength.

Changes in postural balance associated with a woman's aging process.

CONTEXT: Aging causes a progressive worsening in postural balance, affecting functional independence and increasing the risk of falls. OBJECTIVE: The aim of the study was to evaluate the effect of aging on the static balance in women from 50-years to 89-years of age. DESIGN: This was a cross-sectional study, with 400 irregularly active women were evaluated and grouped by age: Group 6th decade (age 50 to 59) ‒ 58 participants; Group 7th decade (age 60 to 69) ‒ 214 participants; Group 8th decade (age 70 to 79) ‒ 92 participants; Group 9th decade (age 80 to 89) ‒ 36 participants. Postural balance was evaluated using a portable force platform in a standard standing position, with Eyes Open (EO) and Eyes Closed (EC). RESULTS: In the two measurement conditions, the elderly women in Group 9th decade presented mediolateral displacement and range, and mean velocity greater than the women's values in Groups 6th and 7th decade. In the EO e EC situation, the displacement was higher in the elderly Group 9th decade compared to younger groups. Group 8th has a mean velocity greater than Group 6th decade in the EO situation. CONCLUSIONS: Posturography showed a decline in postural balance with advancing age, suggesting that the 9th decade of life is a borderline age to this detriment due to an increase in postural instability.

Adherence rate, barriers to attend, safety and overall experience of a physical exercise program via telemonitoring during COVID-19 pandemic for individuals with Parkinson's disease: A feasibility study.

BACKGROUND: Telemonitoring can maintain daily exercise routine during the COVID-19 pandemic of individuals with Parkinson's disease (PD). However, there are barriers to adherence and attendance with remote physical rehabilitation. The main objective of this study was to evaluate adherence rate, barriers to attendance, and safety of a telemonitoring program for individuals with PD; and secondarily to evaluate the individual and their family members perceived overall experience when performing the telemonitoring physical exercise program. METHODS: This was a phase 1 of a clinical trial, engaging 19 individuals with idiopathic PD of an in-person community rehabilitation program. For 24 weeks an asynchronous telemonitoring physical exercise program delivered two sessions per week by video including warm-up, balance, aerobic and resistance exercises, and cool-down. During the remote program were verified: adherence rate at entrance, attendance rate, barriers to attend, safety, and overall experience of the program. RESULTS AND CONCLUSION: Only one participant did not perform any session and 18 participants completed between 2 and 34 sessions. Participants with a caregiver showed higher attendance rates. The most frequently cited barriers to attend the program were: pain; lack of motor skills; and reduced physical fitness. In relation to safety of the program, the most frequently reported was fear of falling. Although participants reported the telemonitoring program induced health benefits and they had positive experiences for themselves and for their families, most of participants prefer an in-person program. In this sense, the asynchronous telemonitoring physical exercise program was safe, showed moderate adherence, with attendance rate depending on the presence of a companion.

Gait and posture are correlated domains in Parkinson's disease.

Establishing a relationship between gait and posture in patients with Parkinson's disease (PD) is essential for PD treatment and rehabilitation. While previous studies have indicated that gait and posture are independent domains in PD, shared neuromechanisms related to gait and posture control and previous studies investigating the relationship between gait and posture parameters in stroke survivors and neurologically healthy older adults have shown a correlated domain. Thus, this study analyzed the relationship of gait and posture domains, primarily through gait temporal sub-phases (i.e., double support and stance phases) and step width. We analyzed the spatial-temporal gait parameters at the self-selected velocity and center of pressure (CoP) during quiet standing of 22 idiopathic PD participants under and without dopaminergic medication conditions. The association between quiet standing and gait variables was assessed through the Spearman test, controlled by age, disease duration, NFoG-Q, and levodopa dosage. In ON medication, CoP area showed a significant correlation with stance phase and total double support; and RMS ML CoP showed a significant correlation with stance phase, total double support, and step width. In OFF medication, CoP area, RMS AP CoP, RMS ML CoP, and ML CoP velocity significantly correlated with stance phase and total double support. By showing the relationship between gait and posture domains in PD, our study adds novel knowledge about the shared gait-posture control, which could collaborate with new approaches during mobility treatment and assessment.

Bilateral capacity is related to bilateral upper limb use after stroke: a study by behavioral maps, accelerometers and perceived amount of use.

PURPOSE: This study aimed to assess the following in individuals after stroke: (1) relationship between upper limb (UL) use by direct observation at home with use perceived and measured by accelerometers; (2) complementarity of these three measurements; and (3) relationship between UL bilateral capacity and bilateral use. MATERIALS AND METHODS: Thirty-one individuals with chronic hemiparesis participated in this cross-sectional study. UL use was assessed using a behavioral map (BM), the Motor Activity Log-Amount of Use (MAL-AOU), and accelerometers, while UL capacity was assessed using the Test d'Evaluation des Membres Supérieurs des Personnes Âgées (TEMPA). RESULTS: The BM was strongly correlated with perceived use (MAL-AOU, ρ = 0.76) and accelerometer (ρ = 0.70). Bilateral UL use (BM) was moderately (ρ = 0.65) correlated with bilateral MAL-AOU and bilateral use by accelerometers (ρ = 0.62). The BM aided our understanding of how the paretic UL was used. The correlation between bilateral capacity (TEMPA bilateral) and bilateral use (BM) was significant (ρ = 0.49), while that with bilateral MAL-AOU and accelerometer were ρ = 0.68 and ρ = 0.50, respectively. CONCLUSION: A BM is a valid way to quantify UL use and can complement information assessed regarding perceived use and by accelerometers.Implications for rehabilitationBehavioral maps may be valuable to complement information assessed by perceived UL use and accelerometers.Quantifying bilateral capacity will reflect in a better understanding of actual paretic UL use after stroke.Accelerometers can underestimate the amount of paretic UL use in asymmetrical bilateral tasks.

Changes in postural balance associated with a woman's aging process

Abstract Context Aging causes a progressive worsening in postural balance, affecting functional independence and increasing the risk of falls. Objective The aim of the study was to evaluate the effect of aging on the static balance in women from 50-years to 89-years of age. Design This was a cross-sectional study, with 400 irregularly active women were evaluated and grouped by age: Group 6thdecade (age 50 to 59) ‒ 58 participants; Group 7thdecade (age 60 to 69) ‒ 214 participants; Group 8thdecade (age 70 to 79) ‒ 92 participants; Group 9thdecade (age 80 to 89) ‒ 36 participants. Postural balance was evaluated using a portable force platform in a standard standing position, with Eyes Open (EO) and Eyes Closed (EC). Results In the two measurement conditions, the elderly women in Group 9thdecade presented mediolateral displacement and range, and mean velocity greater than the women's values in Groups 6thand 7thdecade. In the EO e EC situation, the displacement was higher in the elderly Group 9thdecade compared to younger groups. Group 8thhas a mean velocity greater than Group 6thdecade in the EO situation. Conclusions Posturography showed a decline in postural balance with advancing age, suggesting that the 9thdecade of life is a borderline age to this detriment due to an increase in postural instability.

The variability of isokinetic ankle strength is different in healthy older men and women

Abstract Context In the elderly, weak lower limb muscles impair functional tasks' performance. Objective To evaluate the healthy elderly's ankle dorsiflexion and plantarflexion maximum torque and its variability in two sets of 5 RM isokinetics evaluation. Method 50 women (68.0 ± 4.6 years old) and 50 men (72.7 ± 8.5 years old) did two sets of ankle plantar flexor and dorsiflexor isokinetic tests at 30°/s. Peak torque, total work, and coefficient of variation were analyzed. Results Men did the strongest plantarflexion torque (p < 0.05) and dorsiflexion torque (p < 0.05); their highest peak torque occurred at set 2 (p < 0.05), while the largest plantarflexion torque variability (p < 0.05), dorsiflexion torque variability (p < 0.05), and the largest plantarflexion torque variability occurred at set 1 (p < 0.05). Men did the highest plantarflexion and dorsiflexion total work (p < 0.05) at set 2 (p < 0.05). Conclusion Older men are stronger than older women. The torque variability, in men, was higher during the first set, suggesting an adaptation to the isokinetics evaluation. Clinicians and researchers should consider that different muscles might need different numbers of sets and trials to measure their maximal muscle strength.

Adherence Rate, Barriers to Attend, Safety, and Overall Experience of a Remote Physical Exercise Program During the COVID-19 Pandemic for Individuals After Stroke.

Introduction: The actions taken by the government to deal with the consequences of the coronavirus diseases 2019 (COVID-19) pandemic caused different levels of restriction on the mobility of the population. The need to continue offering physical exercise to individuals after stroke became an emergency. However, these individuals may have barriers to adhere to the programs delivered remotely. There is a lack of evidence related to adherence, attendance, safety, and satisfaction of remote exercise programs for this population. Objective: The aim was to evaluate adherence and barriers to attend a remote physical exercise program for individuals after stroke. We aimed (a) to identify adherence and attendance rate of the remote physical exercise program (i.e., number of participants engaged, number of sessions attended, and exercise time in remote program); (b) to identify the safety of a remote physical exercise program (i.e., falls, pain, or dizziness when performing the exercises, fear, or insecurity); and (c) to identify the overall experience to participate in a remote program. Materials and methods: This is a longitudinal study, including 36 stroke survivors who already attended a face-to-face physical exercise program prior to the COVID-19 pandemic. The remote physical exercise program included sessions for 2 days/week for a duration of 22 weeks, with a total of 44 sessions, which were delivered asynchrony via recorded video sessions. As outcome measures, we performed two questionnaires (via weekly telephone calls) to identify attendance, barriers, safety, and overall experience related to the program. Results: The adherence rate was 86 (9%). The attendance rate was 19, with a total of 8 sessions (108.3 min/week). The main barriers for lower attendance rate were as follows: lack of motor skills and physical fitness to workout in 80 reports (20.6%), followed by no exercise companion in 44 reports (11.3%). The remote physical program has been shown to be safe, and the overall experience was positive from the perspectives of the participants and the family members. Conclusion: Although the adherence rate was high, the attendance rate was low on the remote physical exercise program. The main barriers to attending the program remotely reflect the need of tailoring individually an asynchrony mode of delivering the sessions to individuals after stroke. Our results also indicate how the COVID-19 impacted the health conditions of stroke survivors. The program was safe, and the overall experience indicated a change in the mental, physical, and social health of individuals after stroke and their family members.

Biomechanical evaluation in runners with Achilles tendinopathy.

OBJECTIVES: To evaluate the clinical characteristics, ground reaction force (GRF), and function of the plantar muscles and dorsiflexors of the ankle in runners with and without Achilles tendinopathy (AT) and in non-runners. METHODS: Seventy-two participants (42 men, 30 women; mean age: 37.3±9.9 years) were enrolled in this cross-sectional study and divided into three groups: AT group (ATG, n=24), healthy runners' group (HRG, n=24), and non-runners' group (NRG, n=24). Both ankles were evaluated in each group. The American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale was used for clinical and functional evaluation. GRF was evaluated using force plates and muscle strength was evaluated using an isokinetic dynamometer. RESULTS: The AOFAS scores were lower in the ATG. The strike impulse was higher in the ATG than in the HRG and NRG. However, GRF was similar among the groups. The ATG exhibited lower total work at 120°/s speed than the HRG. The peak torque in concentric dorsiflexion was lower in the NRG than in the ATG and HRG. The peak torque and total work in concentric plantar flexion were lower in the NRG than in the ATG. The peak torque and total work in eccentric plantar flexion were lower in the NRG than in the ATG and HRG. CONCLUSION: Runners with AT showed higher strike impulse, lower muscle strength of the plantar flexors, and higher clinical and functional damage.

What is the exercise intensity of Pilates? An analysis of the energy expenditure, blood lactate, and intensity of apparatus and mat Pilates sessions.

BACKGROUND: Pilates is a form of exercise commonly used in rehabilitation settings that improves muscular fitness and flexibility. However, it is unknown whether the energy expenditure (EE) from Pilates sessions could also lead to the intensity suggested by health organizations to improve physical fitness. This study aimed to quantify and compare the intensity and the EE of two different Pilates sessions (mat and apparatus). METHODS: 18 healthy females (age: 22 ± 3 years; height: 1.6 ± 0.1m; body mass: 61.0 ± 10.0 kg; body mass index: 21 ± 3 kg/m2) performed two different sessions. Each session involved the performance of 15 exercises. Oxygen consumption (V˙O2) was measured continuously and then converted to EE in Kcal/min. Blood lactate, heart rate (HR), and blood pressure (BP) were also measured. A repeated measures two-way ANOVA (time X group) determined differences between sessions. Bonferroni's post hoc analysis was used to identify significant differences between measures. RESULTS: The Reformer apparatus and Mat sessions presented an EE of 2.59 ± 0.53 and 1.93 ± 0.26 kcal/min, respectively. V˙O2 was higher for the Reformer session (8.67 ± 1.15 ml/kg/min) when compared to Mat (6.44 ± 0.73 ml/kg/min). There was no significant increase in blood lactate, HR, and BP for either session above resting values. CONCLUSION: The Pilates sessions analyzed in this study elicit low cardiovascular stress, leading to low EE levels. However, a typical session performed on the Reformer apparatus presented a higher EE, V˙O2, and HR compared to the Mat Pilates session.

Joint-Position Sense Accuracy Is Equally Affected by Vision among Children with and without Cerebral Palsy.

We compared the effect of visual information on the dominant upper limb position sense of children with diplegic cerebral palsy (n = 10) and normally developing children (n = 10). An isokinetic dynamometer passively moved the dominant forearm in 120° of elbow flexion/extension until the volunteers stopped the machine to indicate that the elbow joint was positioned in the predetermined target angle. Participants performed this task five times in sequence with and without visual feedback of the elbow angle. We calculated the absolute and the relative position errors related to the final elbow position and the target angle. In both groups, absolute error was significantly higher when vision was occluded. Relative error was not affected by cerebral palsy or visual feedback. When vision was occluded, accuracy on this task was similarly impaired in both groups and precision was not disturbed.

Prolonged Standing Task Affects Adaptability of Postural Control in People With Parkinson's Disease.

BACKGROUND: Studies on short-term upright quiet standing tasks have presented contradictory findings about postural control in people with Parkinson's disease (pwPD). Prolonged trial durations might better depict body sway and discriminate pwPD and controls. OBJECTIVE: The aim of this study was to investigate postural control in pwPD during a prolonged standing task. METHODS: A total of 26 pwPD and 25 neurologically healthy individuals performed 3 quiet standing trials (60 s) before completing a constrained prolonged standing task for 15 minutes. Motion capture was used to record body sway (Vicon, 100 Hz). To investigate the body sway behavior during the 15 minutes of standing, the analysis was divided into three 5-minute-long phases: early, middle, and late. The following body sway parameters were calculated for the anterior-posterior (AP) and medial-lateral (ML) directions: velocity, root-mean-square, and detrended fluctuations analysis (DFA). The body sway area was also calculated. Two-way ANOVAs (group and phases) and 1-way ANOVA (group) were used to compare these parameters for the prolonged standing and quiet standing, respectively. RESULTS: pwPD presented smaller sway area (P < .001), less complexity (DFA; AP: P < .009; ML: P < .01), and faster velocity (AP: P < .002; ML: P < .001) of body sway compared with the control group during the prolonged standing task. Although the groups swayed similarly (no difference for sway area) during quiet standing, they presented differences in sway area during the prolonged standing task (P < .001). CONCLUSIONS: Prolonged standing task reduced adaptability of the postural control system in pwPD. In addition, the prolonged standing task may better analyze the adaptability of the postural control system in pwPD.