Marco Godi

Comparison of Reliability, Validity, and Responsiveness of the Mini-BESTest and Berg Balance Scale in Patients With Balance Disorders

Background Recently, a new tool for assessing dynamic balance impairments has been presented: the 14-item Mini-BESTest. Objective The aim of this study was to compare the psychometric performance of the Mini-BESTest and the Berg Balance Scale (BBS). Design A prospective, single-group, observational design was used in the study. Methods Ninety-three participants (mean age=66.2 years, SD=13.2; 53 women, 40 men) with balance deficits were recruited. Interrater (3 raters) and test-retest (1–3 days) reliability were calculated using intraclass correlation coefficients (ICCs). Responsiveness and minimal important change were assessed (after 10 sessions of physical therapy) using both distribution-based and anchor-based methods (external criterion: the 15-point Global Rating of Change [GRC] scale). Results At baseline, neither floor effects nor ceiling effects were found in either the Mini-BESTest or the BBS. After treatment, the maximum score was found in 12 participants (12.9%) with BBS and in 2 participants (2.1%) with Mini-BESTest. Test-retest reliability for total scores was significantly higher for the Mini-BESTest (ICC=.96) than for the BBS (ICC=.92), whereas interrater reliability was similar (ICC=.98 versus .97, respectively). The standard error of measurement (SEM) was 1.26 and the minimum detectable change at the 95% confidence level (MDC95) was 3.5 points for Mini-BESTest, whereas the SEM was 2.18 and the MDC95 was 6.2 points for the BBS. In receiver operating characteristic curves, the area under the curve was 0.92 for the Mini-BESTest and 0.91 for the BBS. The best minimal important change (MIC) was 4 points for the Mini-BESTest and 7 points for the BBS. After treatment, 38 participants evaluated with the Mini-BESTest and only 23 participants evaluated with the BBS (out of the 40 participants who had a GRC score of ≥3.5) showed a score change equal to or greater than the MIC values. Limitations The consecutive sampling method drawn from a single rehabilitation facility and the intrinsic weakness of the GRC for calculating MIC values were limitations of the study. Conclusions The 2 scales behave similarly, but the Mini-BESTest appears to have a lower ceiling effect, slightly higher reliability levels, and greater accuracy in classifying individual patients who show significant improvement in balance function.

Stabilometry is a predictor of gait performance in chronic hemiparetic stroke patients

In patients with spastic hemiparesis, centre of foot pressure (CoP) is shifted toward the unaffected limb during quiet stance. We hypothesised that abnormal gait features would correlate with the degree of asymmetry during stance. In 15 patients and 17 normals we recorded CoP and body sway by a force platform and measured spatial-temporal variables of gait with pedobarography. In patients CoP was shifted toward the unaffected limb and sway was larger than in normals. CoP position was associated with the decrease in strength of the affected lower-limb muscles. Spatio-temporal variables of gait were also affected by the disease. Cadence and velocity were decreased, duration of single support on the unaffected limb and of double support were increased with respect to normals. The degree of impairment of gait variables correlated with CoP. We found a negative relationship between velocity or cadence and CoP, and a positive relationship between duration of single support and CoP in the unaffected but not in the affected limb. Duration of double support correlated positively with CoP. CoP asymmetry during both standing and walking suggests that postural and gait problems share some common neural origin in hemiparetic patients. This asymmetry affects gait performance by increasing the time and effort needed to shift body weight toward the affected limb. The degree of postural asymmetry measured by stabilometry is associated with the level of impairment of gait variables.

Eye tracking communication devices in amyotrophic lateral sclerosis: Impact on disability and quality of life

Abstract People with amyotrophic lateral sclerosis (PwALS) show progressive loss of voluntary muscle strength. In advanced disease, motor and phonatory impairments seriously hinder the patients interpersonal communication. High-tech devices such as eye tracking communication devices (ETCDs) are used to aid communication in the later stages of ALS. We sought to evaluate the effect of ETCDs on patient disability, quality of life (QoL), and user satisfaction, in a group of 35 regular ETCD users in late-stage ALS with tetraplegia and anarthria. The following scales were administered: 1) the Individually Prioritized Problem Assessment (IPPA) scale, in three conditions: without device, with ETCD and, when applicable, with an Eye Transfer (ETRAN) board; 2) the Psychosocial Impact of Assistive Devices Scale (PIADS); and 3) the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0). With ETRAN, IPPA showed an increase in communicative abilities with respect to the condition without device, but ETCD produced a further significant increase. PIADS evidenced a large increase of QoL, and QUEST 2.0 showed high user satisfaction with ETCD use. In conclusion, ETCDs should be considered in late-stage ALS with tetraplegia and anarthria, since in these patients they can reduce communication disability and improve QoL.

Balance Rehabilitation by Moving Platform and Exercises in Patients With Neuropathy or Vestibular Deficit

OBJECTIVE To assess the efficacy of a balance rehabilitation treatment by using both a powered platform on which subjects stand and specific physical exercises (EXs). DESIGN Crossover trial. SETTING Physical and rehabilitation medicine department in Italy. PARTICIPANTS Patients (N=33) with balance disorders (14 vestibular origin, 19 peripheral neuropathy origin). INTERVENTIONS Patients underwent powered platform then EX treatment (n=17); the other 16 received the same treatments in reverse order. powered platform consisted of balancing on a sinusoidally oscillating powered platform (in anteroposterior and laterolateral directions in separate trials) with eyes open and closed. A physical therapist administered Cawthorne-Cooksey EXs for patients with vestibular disorders and modified Frenkel EXs for patients with neuropathy. Treatment lasted 1 hour a day for 10 consecutive days, except for the weekend. MAIN OUTCOME MEASURES Body sway area, subjective score of stability, balance and gait scores, and amplitude of head displacement while balancing on the oscillating powered platform were recorded before, (t0) after the first (t1), and after the second treatment (t2), regardless of the powered platform or EX order. RESULTS On average, all participants improved balance regardless of the order of treatments, and more so at t2 than t1. Improvement was observed by using instrumental evaluations and balance and gait scales. In both patient groups, powered platform treatment proved to be as effective as EX in improving balance. This effect was stronger in patients with vestibular disorders, independently of order of treatment. CONCLUSIONS Balance rehabilitation with either EX or powered platform is effective in patients with balance disorders of vestibular or neuropathic origin. These findings point to the value of either or both physical EXs and powered platform in increasing stability and potentially decrease the risk of falling in patients with neuropathy, for whom few results are documented in the literature.

Alternate rhythmic vibratory stimulation of trunk muscles affects walking cadence and velocity in Parkinson’s disease

OBJECTIVE During the administration of timed bilateral alternate vibration to homonymous leg or trunk muscles during quiet upright stance, Parkinsonian (PD) patients undergo cyclic antero-posterior and medio-lateral transfers of the centre of foot pressure. This event might be potentially exploited for improving gait in these patients. Here, we tested this hypothesis by applying alternate muscle vibration during walking in PD. METHODS Fifteen patients and 15 healthy subjects walked on an instrumented walkway under four conditions: no vibration (no-Vib), and vibration of tibialis anterior (TA-Vib), soleus (Sol-Vib) and erector spinae (ES-Vib) muscles of both sides. Trains of vibration (internal frequency 100 Hz) were delivered to right and left side at alternating frequency of 10% above preferred step cadence. RESULTS During vibration, stride length, cadence and velocity increased in both patients and healthy subjects, significantly so for ES-Vib. Stance and swing time tended to decrease. Width of support base increased with Sol-Vib or TA-Vib, but was unaffected by ES-Vib. CONCLUSIONS Alternate ES vibration enhances gait velocity in PD. The stronger effect of ES over leg muscle vibration might depend on the relevance of the proprioceptive inflow from the trunk muscles and on the absence of adverse effects on the support base width. SIGNIFICANCE Trunk control is defective in PD. The effect of timed vibratory stimulation on gait suggests the potential use of trunk proprioceptive stimulation for tuning the central pattern generators for locomotion in PD.

Walking along circular trajectories in Parkinson's disease.

We hypothesized that gait capacities would be more stressed in patients with Parkinsons disease (PD) when walking along curved than straight trajectories, owing to the complex adaptations required for this walking task. Twenty on‐phase patients with PD and 20 healthy subjects walked eyes‐open along straight and curved trajectories for 1 minute at self‐paced cadence and velocity. Step frequency along straight and curved trajectories was computed from video‐recordings of the lower limbs. Step frequency was not affected by trajectory shape in either patients with PD or healthy subjects. Distances run by the patients were shorter than normal under both conditions. However, in PD, distances were relatively shorter during curved than straight walking; therefore, decreased distances in PD were connected with decreased mean step length (as the ratio between distance and step number). No correlation was found between the above mentioned variables and the severity or duration of the disease or the frequency of falls. Walking along curved trajectories can highlight impaired gait control in on‐phase patients with PD, and can be suitable for the routine evaluation of possible walking disorders when straight walking is not significantly affected.

Test-retest reliability of an insole plantar pressure system to assess gait along linear and curved trajectories

BackgroundPrevious studies have assessed reliability of insole technology for evaluating foot pressure distribution during linear walking. Since in natural motion straight walking is intermingled with turns, we determined the test-retest reliability of insole assessment for curved as well as linear trajectories, and estimated the minimum number of steps required to obtain excellent reliability for each output variable.MethodsSixteen young healthy participants were recruited. Each performed, two days apart, two sessions of three walking conditions: linear (LIN) and curved, clockwise (CW) and counter-clockwise (CCW). The Pedar-X system was used to collect pressure distribution. Foot print was analyzed both as a whole and as subdivided into eight regions: medial and lateral heel, medial and lateral arch, I metatarsal head, II-V metatarsal heads, hallux, lateral toes. Reliability was assessed by using intraclass correlation coefficient (ICC) for clinically relevant variables from analysis of 50 steps per trajectory: Peak Force (PF); Peak Pressure (PP); Contact Area (CA); Stance Duration (S).ResultsWhen considering whole-foot, all variables showed an ICC >0.80, therefore highly reliable. This was true for both LIN and curved trajectories. There was no difference in ICC of the four variables between left and right foot. When collapsing foot and trajectories, S had a lower ICC than PP and CA, and PP lower than CA. Mean percent error between the values of first and second session was <5%. When separately considering the eight foot regions, ICCs of PF, PP and CA for all regions and trajectories were generally >0.90, indicating excellent reliability. In curved trajectories, S showed smaller ICCs. Since the least ICC value for S was 0.60 in LIN trajectory, we estimated that to achieve an ICC ≥0.90 more than 200 steps should be collected.ConclusionsHigh reliability of insole dynamic variables (PF, PP, CA) is obtained with 50 steps using the Pedar-X system. On the contrary, high reliability of temporal variable (S) requires a larger step number. The negligible differences in ICC between LIN and curved trajectory allow use of this device for gait assessment along mixed trajectories in both clinical and research setting.

Curved walking in hemiparetic patients.

OBJECTIVE Curved walking requires complex adaptations, including shift of body weight to counteract the ensuing centrifugal force, and the production of strides of different length between legs. We hypothesized that gait capacities would be more stressed in hemiparetic patients than in healthy subjects when walking along curved, compared with straight, trajectories. METHODS Twenty chronic, stabilized stroke patients and 20 healthy subjects walked along straight or curved trajectories. Mean cadence and gait velocity were off-line computed from video recordings. An electronic walkway detected asymmetry of single support and degree of foot yaw angle at mid-stance. Centre of pressure during standing was recorded by posturography. RESULTS Compared with linear walking, the velocity of curved walking was not significantly smaller in patients, and was independent of affected body side or direction of rotation. It was inversely correlated with paretic limb weakness, asymmetry of single support, and shift of centre of pressure toward the healthy side. External rotation of the paretic foot relatively favoured curved walking toward the paretic side. CONCLUSION Curved locomotion is defective in stabilized stroke patients, but impairment is not dependent on direction of rotation, indicating a shared task between legs or occurrence of effective functional adaptation. These findings advocate rehabilitation exercises targeting complex gait adaptations, including curved walking.

The generation of centripetal force when walking in a circle: insight from the distribution of ground reaction forces recorded by plantar insoles.

BackgroundTurning involves complex reorientation of the body and is accompanied by asymmetric motion of the lower limbs. We investigated the distribution of the forces under the two feet, and its relation to the trajectory features and body medio-lateral displacement during curved walking.MethodsTwenty-six healthy young participants walked under three different randomized conditions: in a straight line (LIN), in a circular clockwise path and in a circular counter-clockwise path. Both feet were instrumented with Pedar-X insoles. An accelerometer was fixed to the trunk to measure the medio-lateral inclination of the body. We analyzed walking speed, stance duration as a percent of gait cycle (%GC), the vertical component of the ground reaction force (vGRF) of both feet during the entire stance, and trunk inclination.ResultsGait speed was faster during LIN than curved walking, but not affected by the direction of the curved trajectory. Trunk inclination was negligible during LIN, while the trunk was inclined toward the center of the path during curved trajectories. Stance duration of LIN foot and foot inside the curved trajectory (Foot-In) was longer than for foot outside the trajectory (Foot-Out). vGRF at heel strike was larger in LIN than in curved walking. At mid-stance, vGRF for both Foot-In and Foot-Out was higher than for LIN foot. At toe off, vGRF for both Foot-In and Foot-Out was lower than for LIN foot; in addition, Foot-In had lower vGRF than Foot-Out. During curved walking, a greater loading of the lateral heel occurred for Foot-Out than Foot-In and LIN foot. On the contrary, a smaller lateral loading of the heel was found for Foot-In than LIN foot. At the metatarsal heads, an opposite behaviour was seen, since lateral loading decreased for Foot-Out and increased for Foot-In.ConclusionsThe lower gait speed during curved walking is shaped by the control of trunk inclination and the production of asymmetric loading of heel and metatarsal heads, hence by the different contribution of the feet in producing the body inclination towards the centre of the trajectory.

Intensive cycle ergometer training improves gait speed and endurance in patients with Parkinson’s disease: A comparison with treadmill training

PURPOSE Cycle ergometer training improves gait in the elderly, but its effect in patients with Parkinsons disease (PD) is not completely known. METHODS Twenty-nine PD inpatients were randomized to treadmill (n = 13, PD-T) or cycle ergometer (n = 16, PD-C) training for 3 weeks, 1 hour/day. Outcome measures were distance travelled during the 6-min walking test (6MWT), spatio-temporal variables of gait assessed by baropodometry, the Timed Up and Go (TUG) duration, the balance score through the Mini-BESTest, and the score of the Unified Parkinsons Disease Rating Scale (UPDRS). RESULTS Sex, age, body mass index, disease duration, Hoehn-Yahr staging, comorbidity and medication did not differ between groups. At end of training, ANCOVA showed significant improvement, of similar degree, in both groups for 6MWT, speed, step length and cadence of gait, TUG, Mini-BESTest and UPDRS. CONCLUSIONS This pilot study shows that cycle ergometer training improves walking parameters and reduces clinical signs of PD, as much as treadmill training does. Gait velocity is accompanied by step lengthening, making the gait pattern close to that of healthy subjects. Cycle ergometer is a valid alternative to treadmill for improving gait in short term in patients with PD.