Dynamic Stability and Risk of Tripping during the Timed Up and Go Test in Hemiparetic and Healthy Subjects

Cautious Gait during Navigational Tasks in People with Hemiparesis: An Observational Study

Locomotor and balance disorders are major limitations for subjects with hemiparesis. The Timed Up and Go (TUG) test is a complex navigational task involving oriented walking and obstacle circumvention. We hypothesized that subjects with hemiparesis adopt a cautious gait during complex locomotor tasks. The primary aim was to compare spatio-temporal gait parameters, indicators of cautious gait, between the locomotor subtasks of the TUG (Go, Turn, Return) and a Straight-line walk in people with hemiparesis. Our secondary aim was to analyze the relationships between TUG performance and balance measures, compare spatio-temporal gait parameters between fallers and non-fallers, and identify the biomechanical determinants of TUG performance. Biomechanical parameters during the TUG and Straight-line walk were analyzed using a motion capture system. A repeated measures ANOVA and two stepwise ascending multiple regressions (with performance variables and biomechanical variables) were conducted. Gait speed, step length, and % single support phase (SSP) of the 29 participants were reduced during Turn compared to Go and Return and the Straight-line walk, and step width and % double support phase were increased. TUG performance was related to several balance measures. Turn performance (R2 = 63%) and Turn trajectory deviation followed by % SSP on the paretic side and the vertical center of mass velocity during Go (R2 = 71%) determined TUG performance time. People with hemiparesis adopt a cautious gait during complex navigation at the expense of performance.

Validity of an android device for assessing mobility in people with chronic stroke and hemiparesis: a cross-sectional study

BACKGROUND

Incorporating instrument measurements into clinical assessments can improve the accuracy of results when assessing mobility related to activities of daily living. This can assist clinicians in making evidence-based decisions. In this context, kinematic measures are considered essential for the assessment of sensorimotor recovery after stroke. The aim of this study was to assess the validity of using an Android device to evaluate kinematic data during the performance of a standardized mobility test in people with chronic stroke and hemiparesis.

METHODS

This is a cross-sectional study including 36 individuals with chronic stroke and hemiparesis and 33 age-matched healthy subjects. A simple smartphone attached to the lumbar spine with an elastic band was used to measure participants' kinematics during a standardized mobility test by using the inertial sensor embedded in it. This test includes postural control, walking, turning and sitting down, and standing up. Differences between stroke and non-stroke participants in the kinematic parameters obtained after data sensor processing were studied, as well as in the total execution and reaction times. Also, the relationship between the kinematic parameters and the community ambulation ability, degree of disability and functional mobility of individuals with stroke was studied.

RESULTS

Compared to controls, participants with chronic stroke showed a larger medial-lateral displacement (p = 0.022) in bipedal stance, a higher medial-lateral range (p < 0.001) and a lower cranio-caudal range (p = 0.024) when walking, and lower turn-to-sit power (p = 0.001), turn-to-sit jerk (p = 0.026) and sit-to-stand jerk (p = 0.001) when assessing turn-to-sit-to-stand. Medial-lateral range and total execution time significantly correlated with all the clinical tests (p < 0.005), and resulted significantly different between independent and limited community ambulation patients (p = 0.042 and p = 0.006, respectively) as well as stroke participants with significant disability or slight/moderate disability (p = 0.024 and p = 0.041, respectively).

CONCLUSION

This study reports a valid, single, quick and easy-to-use test for assessing kinematic parameters in chronic stroke survivors by using a standardized mobility test with a smartphone. This measurement could provide valid clinical information on reaction time and kinematic parameters of postural control and gait, which can help in planning better intervention approaches.

Strategies Adopted by Stroke Patients to Maintain Balance in Dynamic Tasks in a Video Game

Postural instability affects motor tasks after a stroke. We investigated the strategies used to maintain balance during quiet standing posture and dynamic tasks in a video game. Sixteen stroke volunteers (12 males, 56 ± 9 years, post-stroke time 35 ± 10 months) and sixteen matched healthy volunteers had their biomechanical data collected to obtain the variables: center of mass, base of support, margin of stability, and weight symmetry. Healthy individuals and stroke patients showed similar dynamic stability. However, they adopted different motor strategies to achieve this: healthy individuals increased their base of support as they progressed to more challenging tasks, and stroke volunteers maintained the same base. The margin of stability of stroke volunteers was correlated with the MiniBEST scale.

Determinants and Characterization of Locomotion in Adults with Late-Onset Pompe Disease: New Clinical Biomarkers

BACKGROUND

The late-onset form of Pompe disease (LOPD) is characterized by muscle weakness, locomotor limitations and a risk of falls. The mechanisms responsible for altered locomotion in adults with LOPD are unknown. The identification of clinical biomarkers is essential for clinical follow-up and research.

OBJECTIVES

To identify muscle determinants of impaired locomotor performance, gait stability and gait pattern, and biomechanical determinants of falls in adults with LOPD.

METHODS

In this cross-sectional, case-control study, LOPD and control participants underwent 3D gait analysis, locomotor performance tests and muscle strength measurements (isokinetic dynamometer). We explored the muscular determinants of locomotor performance (gait speed, 6-minute walk test distance and timed up and go test), gait stability (spatiotemporal gait variables) and the gait pattern. We also explored biomechanical gait determinants of falls. After intergroup comparisons, determinants were sought to use forward stepwise multiple regression.

RESULTS

Eighteen participants with LOPD and 20 control participants were included. Locomotor performance, gait stability, and the gait pattern were significantly altered in LOPD compared to control participants. Hip abductor strength was the main common determinant of locomotor performance, gait stability and pelvic instability. Hip flexor strength was the main determinant of abnormal gait kinematics at the hip and knee. Percentage duration of single support phase during the gait cycle was the main determinant of falls.

CONCLUSIONS

Hip abductor strength and percentage duration of single support during gait were the major determinants of locomotor performance, gait stability, falls and the gait pattern in LOPD. These new clinical biomarkers should therefore be systematically assessed using instrumented tools to improve the follow-up of adults with LOPD. They should also be considered in future studies to accurately assess the effects of new therapies. Hip abductor strength and single support phase should also be priority targets for rehabilitation.

Effects of Robot-Assisted Gait Training with Body Weight Support on Gait and Balance in Stroke Patients

This study investigated the effects of robot-assisted gait training with body weight support on gait and balance in stroke patients. The study participants comprised 24 patients diagnosed with stroke. Patients were randomly assigned to four groups of six: robot A, B, C, and non-robot. The body weight support (BWS) for the harness of the robot was set to 30% of the patient’s body weight in robot group A, 50% in robot group B, and 70% in robot group C. All experimental groups received robot-assisted gait training and general physical therapy. The non-robot group underwent gait training using a p-bar, a treadmill, and general physical therapy. The intervention was performed for 30 min a day, five times a week, for 6 weeks. All participants received the intervention after the pre-test. A post-test was performed after all of the interventions were completed. Gait was measured using a 10 m Walking test (10MWT) and the timed up and go (TUG) test. Balance was assessed using the Berg Balance Scale (BBS). Robot groups A, B, and C showed significantly better 10MWT results than did the non-robot group (p < 0.5). TUG was significantly shorter in robot groups A, B, and C than in the non-robot group (p < 0.5). The BBS scores for robot group A improved significantly more than did those for robot groups B and C and the non-robot group (p < 0.5), indicating that robot-assisted gait training with body weight support effectively improved the gait of stroke patients.

Effectiveness of Intensively Applied Mirror Therapy in Older Patients with Post-Stroke Hemiplegia: A Preliminary Trial

INTRODUCTION

The present work was carried out to determine the effectiveness of neuromuscular stimulation triggered by mirror therapy (MT) in older patients with post-stroke hemiplegia by two different intervention protocols, either intensively or spaced.

METHODS

A preliminary trial conducted on Spanish rehabilitation centres was conducted. Forty older patients (>70 years) with diagnosed post-stroke hemiplegia were randomly distributed to intensive intervention group (5 times/week for 6 weeks) or to spaced intervention group (3 times/week for 10 weeks), which underwent a similar number of MT sessions (n = 30). Muscle strength and activity were measured at baseline and at the end of treatment. Functional ability was also evaluated.

RESULTS

Although both interventions improved muscle activity parameters, intensive MT showed a significantly and statistically higher intervention effect on electromyographic activity (p < 0.001) and muscle strength (p < 0.001) than the spaced over time protocol. Attending to the Barthel Index scores, the effect on functionality was also greater in the intensive therapy group (p < 0.001), although the functional improvement measured by the Fugl-Meyer test was similar (p = 0.235). The effect of the interventions was independent of age and clinical antecedents.

CONCLUSION

Intensive MT appears to be more effective than a more spaced over time therapy; therefore, at least in the older adults, this treatment protocol should be recommended in the post-stroke recovery of these patients. Further studies will confirm with certainty whether this treatment is the most suitable guideline for to treat these patients.

A Deep Learning Approach for Foot Trajectory Estimation in Gait Analysis Using Inertial Sensors

Gait performance is an important marker of motor and cognitive decline in older adults. An instrumented gait analysis resorting to inertial sensors allows the complete evaluation of spatiotemporal gait parameters, offering an alternative to laboratory-based assessments. To estimate gait parameters, foot trajectories are typically obtained by integrating acceleration two times. However, to deal with cumulative integration errors, additional error handling strategies are required. In this study, we propose an alternative approach based on a deep recurrent neural network to estimate heel and toe trajectories. We propose a coordinate frame transformation for stride trajectories that eliminates the dependency from previous strides and external inputs. Predicted trajectories are used to estimate an extensive set of spatiotemporal gait parameters. We evaluate the results in a dataset comprising foot-worn inertial sensor data acquired from a group of young adults, using an optical motion capture system as a reference. Heel and toe trajectories are predicted with low errors, in line with reference trajectories. A good agreement is also achieved between the reference and estimated gait parameters, in particular when turning strides are excluded from the analysis. The performance of the method is shown to be robust to imperfect sensor-foot alignment conditions.

Effects of Onabotulinum Toxin A on Gait in Parkinson's Disease Patients with Foot Dystonia

We investigated the effects of botulinum toxin on gait in Parkinson's disease (PD) patients with foot dystonia. Six patients underwent onabotulinum toxin A injection and were assessed by Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS), visual analog scale (VAS) of pain, Timed Up and Go (TUG), Berg Balance Test (BBT), and 3D gait analysis at baseline, 1 month, and 3 months. BFMDRS (p = 0.002), VAS (p = 0.024), TUG (p = 0.028), and BBT (p = 0.034) were improved. Foot pressures at Toe 1 (p = 0.028) and Midfoot (p = 0.018) were reduced, indicating botulinum toxin's effects in alleviating the dystonia severity and pain and improving foot pressures during walking in PD.

Combined Effect of Osteoporosis and Poor Dynamic Balance on the Incidence of Sarcopenia in Elderly Chinese Community Suburban-Dwelling Individuals

OBJECTIVES

Given the increasing prevalence of osteoporosis and the important role dynamic balanced plays in the assessment of muscle function, we aimed to examine the joint and separate effects of osteoporosis and poor dynamic balance on the incidence of sarcopenia in Chinese elderly individuals.

DESIGN

This study was conducted on 658 (44.4% male) Chinese suburban-dwelling participants with a mean age of 68.42 ± 5.43 years who initially had no sarcopenia and were aged ≥60 years. A quantitative ultrasound scan of each participant's calcaneus with a T score less than -2.5 was used to identify the prevalence of osteoporosis. Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia criteria. We assessed dynamic balance using the Timed Up and Go Test (TUGT). Participants who scored in the top 20% on the TUGT were defined as having poor dynamic balance.

RESULTS

After a follow-up of three years, the incidence of sarcopenia in the general population was 8.1% (9.6% in males, 6.8% in females). The incidence of sarcopenia was progressively greater in people suffering from both osteoporosis and poor dynamic balance (OR=2.416, 95%CI=1.124-5.195) compared to those who only had osteoporosis (OR=0.797, 95%CI=0.378-1.682) or poor dynamic balance (OR=1.226, 95%CI=0.447-3.363) in models without adjustments. Even after adjusting for potential confounders, the result still held true (OR=2.431, 95%CI=1.053-5.614).

CONCLUSIONS

In our study, we found individuals who suffered from both osteoporosis and poor dynamic balance simultaneously had a significantly higher incidence of sarcopenia than those who suffered from either one or the other.

Center of mass in analysis of dynamic stability during gait following stroke: A systematic review

BACKGROUND

The Center of mass (CoM) analysis reveals important aspects of gait dynamic stability of stroke patients, but the variety of methods and measures represents a challenge for planning new studies.

RESEARCH QUESTION

How have the CoM measures been calculated and employed to investigate gait stability after a stroke? Three issues were addressed: (i) the methodological aspects of the calculation of CoM measures; (ii) the purposes and (iii) the conclusions of the studies on gait stability that employed those measures.

METHODS

PubMed and Science Direct databases have been searched to collect original articles produced until July 2017. A set of 26 studies were selected according to criteria involving their methodological quality.

RESULTS

A compromise between accuracy and feasibility in CoM calculation could be reached using the segmental method with 7-9 segments. Regarding their purposes, two types of studies were identified: clinical and research oriented. From the first ones, we highlighted: the margin of stability (MoS) in the mediolateral (ML) direction, and the angular momentum in the frontal plane could be indicators of dynamical stability; the MoS in the anteroposterior (AP) direction might be able to detect the risk of falls and the symmetry of vertical CoM displacement could be used to analyze energy expenditure during gait. These and other CoM measures are potentially useful in clinical settings, but their psychometric properties are still to be determined. The research oriented studies allowed to clarify that stability is not improved by widening the step in stroke patients and that the impaired control of the non-paretic limb might be the main source of instability.

SIGNIFICANCE

This review provides recommendations on the methods for estimating CoM and its measures, identifies the potential usefulness of CoM parameters and indicates issues that could be addressed in future studies.

The performance of stroke survivors in turning-while-walking while carrying out a concurrent cognitive task compared with controls

Background

Turning-while-walking is one of the commonest causes of falls in stroke survivors. It involves cognitive processing and may be challenging when performed concurrently with a cognitive task. Previous studies of dual-tasking involving turning-while-walking in stroke survivors show that the performance of physical tasks is compromised. However, the design of those studies did not address the response of stroke survivors under dual-tasking condition without specifying the task-preference and its effect on the performance of the cognitive task.

Objective

First, to compare the performance of single-tasking and dual-tasking in stroke survivors.

Second, to compare the performance of stroke survivors with non-stroke controls.

Methods

Fifty-nine stroke survivors and 45 controls were assessed with an auditory Stroop test, a turning-while-walking test, and a combination of the two single tasks. The outcome of the cognitive task was measured by the reaction time and accuracy of the task. The physical task was evaluated by measuring the turning duration, number of steps to turn, and time to complete the turning-while-walking test.

Results

Stroke survivors showed a significantly reduced accuracy in the auditory Stroop test when dual-tasking, but there was no change in the reaction time. Their performance in the turning-while-walking task was similar under both single-tasking and dual-tasking condition. Additionally, stroke survivors demonstrated a significantly longer reaction time and lower accuracy than the controls both when single-tasking and dual-tasking. They took longer to turn, with more steps, and needed more time to complete the turning-while-walking task in both tasking conditions.

Conclusions

The results show that stroke survivors with high mobility function performed the auditory Stroop test less accurately while preserving simultaneous turning-while-walking performance. They also demonstrated poorer performance in both single-tasking and dual-tasking as compared with controls.

Observational Study of 180° Turning Strategies Using Inertial Measurement Units and Fall Risk in Poststroke Hemiparetic Patients

Objective

We analyzed spontaneous 180° turning strategies in poststroke hemiparetic patients by using inertial measurement units (IMUs) and the association of turning strategies with risk of falls.

Methods

We included right paretic (RP) and left paretic (LP) post-stroke patients, and healthy controls (HCs) from a physical and rehabilitation department in France between July 2015 and October 2015. All subjects were right-handed and right-footed for mobilization tasks. Participants were instructed to turn 180° in a self-selected direction after a 10-m walk while wearing three IMUs on their trunk and both feet. We defined three turning patterns based on the number of external steps (pattern I = 1; II = 2–4 steps; and III ≥ 5) and four turning strategies based on the side chosen to turn (healthy or paretic) and the stance limb used during the first step of the turn (healthy or paretic). Falls in the 6 months after measurement were investigated.

Results

We included 17 RP [mean (SD) age 57.5 (9.5) years (range 43–73)], 20 LP patients [mean age 60.7 (8.8) years (range 43–63)], and 15 HCs [mean age 56.7 (16.1) years (range 36–83)]. The LP and RP groups behaved similarly in turning patterns, but 90% of LP patients turned spontaneously to the paretic side versus 59% of RP patients. This difference increased with turning strategies: 85% of LP versus 29% of RP patients used strategy 4 (paretic turn side with paretic limb). Patients using strategy 4 had the highest rate of falls.

Conclusion

We propose to consider spontaneous turning strategies as new indicators to evaluate the risk of fall after stroke. IMU could be routinely used to identify this risk and guide balance rehabilitation programs.

Effects of Functional Electrical Stimulation on Reducing Falls and Improving Gait Parameters in Multiple Sclerosis and Stroke

BACKGROUND

Loss of neuromuscular control of the ankle joint is a common impairment in neurologic conditions, leading to abnormal gait and a greater risk of falling. Limited information, however, is available on the effectiveness of functional electrical stimulation (FES) on reducing falls, and no studies have investigated its usefulness in improving lower limbs kinematics related to foot clearance and energy recovery.

SETTING

Clinical setting.

STUDY DESIGN

Prospective longitudinal study.

PARTICIPANTS

Twenty-four subjects, 14 people with multiple sclerosis (mean age ± standard deviation 50.93 ± 8.72 years) and 10 people with stroke (55.38 ± 14.55 years).

METHODS

The number of falls was assessed at baseline and after 8 weeks, and a clinical assessment was performed at the baseline, 4-week, and 8-week time points. A subsample of the 24 subjects comprising 5 people with multiple sclerosis and 5 people with stroke performed a gait analysis assessment at baseline and after 4 weeks. After receiving the equipment and the training schedule, subjects performed daily home walking training using FES for 8 weeks.

MAIN OUTCOME MEASUREMENTS

The main outcomes were (1) the number of falls, (2) foot clearance, and (3) energy recovery.

RESULTS

A reduction in the number of falls was observed from baseline (n = 10) to the 8-week assessment (n = 2), P = .02. Foot clearance increased (+5.26 mm, P = .04) between the baseline without FES and at 4 weeks with FES (total effect). No statistically significant differences were found in energy recovery between baseline and 4 weeks.

CONCLUSIONS

The use of FES had an impact on gait, specifically reducing the number of falls and improving walking. A specific effect at the ankle joint was observed, increasing foot clearance during the swing phase of gait. This effect was not accompanied with a reduction in the energetic expenditure during walking in subjects with multiple sclerosis and stroke.

Correlation between center of pressure and functional balance in non-faller elderly practitioners of Tai Chi Chuan

[Purpose] This study aimed to determine the correlation between center of pressure and functional balance in non-faller elderly practitioners of Tai Chi. [Subjects and Methods] For the study, nine non-faller elderly practitioners of Tai Chi who were able to maintain a standing posture and walk independently were recruited. Timed one-leg standing and timed up-and-go tests were used as functional balance tests and force platform to measure the center of pressure. The Pearson correlation coefficient was calculated for the timed up-and-go/timed one-leg standing test scores and center of pressure parameter values. [Results] None of the correlations was statistically significant, but moderate correlations were observed between the pairs timed one-leg standing/sway area of center of pressure, timed one-leg standing/standard deviation of center of pressure in the mediolateral direction, timed one-leg standing/mean velocity of center of pressure in the anteroposterior direction, and timed up-and-go test sway area of center of pressure. [Conclusion] Timed one-leg standing is more appropriate than timed up-and-go test for the measurement of functional balance in non-faller elderly practitioners of Tai Chi.