Elisa Gervasoni

ACUTE EFFECTS OF STATIC STRETCHING ON SQUAT JUMP PERFORMANCE AT DIFFERENT KNEE STARTING ANGLES

La Torre, A, Castagna, C, Gervasoni, E, Cè, E, Rampichini, S, Ferrarin, M, and Merati, G. Acute effects of static stretching on squat jump performance at different knee starting angles. J Strength Cond Res 24(3): 687-694, 2010-The purpose of this study was to examine the effects of static stretching on leg extensor muscles during squat jump (SJ) at different knee starting angles. Seventeen male subjects (23 ± 3 years, 179 ± 5 cm, and 74 ± 6 kg) performed on a force platform 2 series (preceded or not [control condition] by 10-minute static stretching of quadriceps and triceps surae muscles) of SJs at different knee starting angles: 50°, 70°, 90°, and 110°. Squat jump height, peak force, maximal acceleration, velocity, and power were calculated for each jump. The angle that maximized power development was obtained from the power-angle relationship. The SJ height, peak force, and maximal velocity increased according to angle amplitude in both control and stretching conditions (p < 0.01), performance being significantly lower in the stretching condition (p < 0.01). Peak power was obtained at 90° in both control and stretching conditions, but was significantly lower (p < 0.01) after stretching. These results suggest that an acute bout of static stretching reduces power and force development during SJ, decrements being significantly higher at lower knee starting angles. Therefore, the use of static stretching may be questionable in those power activities requiring maximal power output at knee angles near full extension.

Minimal Clinically Important Difference of Berg Balance Scale in People With Multiple Sclerosis

OBJECTIVE To identify the minimal clinically important difference (MCID) to define clinically meaningful patients improvement on the Berg Balance Scale (BBS) in people with multiple sclerosis (PwMS) in response to rehabilitation. DESIGN Cohort study. SETTING Neurorehabilitation institute. PARTICIPANTS PwMS (N=110). INTERVENTIONS This study comprised inpatients and outpatients who participated in research on balance and gait rehabilitation. All received 20 rehabilitation sessions with different intensities. Inpatients received daily treatments over a period of 4 weeks, while outpatients received 2 to 3 treatments per week for 10 weeks. MAIN OUTCOME MEASURES An anchor-based approach using clinical global impression of improvement in balance (Activities-specific Balance Confidence [ABC] Scale) was used to determine the MCID of the BBS. The MCID was defined as the minimum change in the BBS total score (postintervention - preintervention) that was needed to perceive at least a 10% improvement on the ABC Scale. Receiver operating characteristic curves were used to define the cutoff of the optimal MCID of the BBS discriminating between improved and not improved subjects. RESULTS The MCID for change on the BBS was 3 points for the whole sample, 3 points for the inpatients, and 2 points for the outpatients. The area under the curve was .65 for the whole sample, .64 for inpatients, and .68 for outpatients. CONCLUSIONS The MCID for improvement in balance as measured by the BBS was 3 points, meaning that PwMS are likely to perceive that as a reproducible and clinically important change in their balance performance.

Effects of fatigue on balance and mobility in subjects with multiple sclerosis: a brief report.

Purpose. People with Multiple Sclerosis (PwMS) tent to have increased levels of fatigue which can impact on their balance and increase risk of falls. However, the relationship between fatigue and balance is poorly understood. The aim of the present study was to assess if an experimentally induced fatigue had an immediate effect on balance. Methods. 37 inpatients with multiple sclerosis were recruited; the mean age (standard deviation) was 48.7 (9.6) years. The average onset of the pathology was 15.3 (9.8) years before the start of the study. The median (1°–3° quartile) Expanded Disability Status Scale (EDSS) score was 5.5 (4.5–6.0). Before and after a fatiguing treadmill, session, subjects were assessed with the Berg Balance Scale and Dynamic Gait Index. Results. After the treadmill, no statistically significant differences were found in balance before and after a treadmill session (monopodalic stance: before 5.3s (10.3) and after 7.7s (13.9); walk with horizontal head turns: before 11.6 (6.9) seconds and after 11.3 (7.7)). There was no correlation between the EDSS score and the difference in balance skills before and after treadmill. Conclusion. After treadmil PwMS were mentally and physically fatigued; however, their balance performance did not change, indicating no increase in risk of falling with fatigue.

Are Modular Activations Altered in Lower Limb Muscles of Persons with Multiple Sclerosis during Walking? Evidence from Muscle Synergies and Biomechanical Analysis

Background: Persons with Multiple Sclerosis frequently have gait deficits that lead to diminished activities of daily living. Identification of motoneuron activity patterns may elucidate new insight into impaired locomotor coordination and underlying neural systems. The aim of the present study was to investigate muscle synergies, identified by motor modules and their activation profiles, in persons with Multiple Sclerosis (PwMS) during walking compared to those of healthy subjects (HS), as well as, exploring relationship of muscle synergies with walking ability of PwMS. Methods: Seventeen PwMS walked at their natural speed while 12 HS walked at slower than their natural speeds in order to provide normative gait values at matched speeds (spatio-temporal, kinematic, and kinetic parameters and electromyography signals). Non-negative matrix factorization was used to identify muscle synergies from eight muscles. Pearsons correlation coefficient was used to evaluate the similarity of motor modules between PwMS and HS. To assess differences in module activations, each modules activation timing was integrated over 100% of gait cycle and the activation percentage was computed in six phases. Results: Fifty-nine% of PwMS and 58% of HS had 4 modules while the remaining of both populations had 3 modules. Module 2 (related to soleus, medial, and lateral gastrocnemius primarily involved in mid and terminal stance) and Module 3 (related to tibialis anterior and rectus femoris primarily involved in early stance, and early and late swing) were comparable across all subjects regardless of synergies number. PwMS had shorter stride length, longer double support phase and push off deficit with respect to HS (p < 0.05). The alterations of activation timing profiles of specific modules in PwMS were associated with their walking deficits (e.g., the reduction of Module 2 activation percentage index in terminal stance, PwMS 35.55 ± 13.23 vs. HS 50.51 ± 9.13% p < 0.05, and the push off deficit, PwMS 0.181 ± 0.136 vs. HS 0.291 ± 0.062 w/kg p < 0.05). Conclusion: During gait PwMS have synergies numbers similar to healthy persons. Their neurological deficit alters modular control through modifications of the timing activation profiles rather than module composition. These changes were associated with their main walking impairment, muscle weakness, and prolonged double support.

Effect of treadmill training on fatigue in multiple sclerosis: a pilot study.

People with multiple sclerosis (PwMS) tend to be less physically active than the general population. Limited physical activity increases fatigue, possibly affecting other functions such as balance. Treadmill training is a promising method to ameliorate these symptoms. The aim of this study was to assess the effect of treadmill training on fatigue and balance. Thirty PwMS were recruited; the mean age was 47.6 (SD 9.2). The median EDSS score was 5.5 (range 3–6.5). Individuals were randomized into a control group receiving 12 sessions of conventional therapy and an experimental group receiving conventional therapy including 15 min of treadmill training. Rate of perceived exertion (RPE), heart rate (HR), the Fatigue Severity Scale, and the Berg Balance Scale were assessed before and after rehabilitation. Despite a low HR (107 beats/min), the RPE score was high (15.8) at baseline assessment. In the experimental group, RPE decreased significantly to 12.8 (P=0.04) after training. Treadmill training also had a positive effect on HR, but no changes in the Fatigue Severity Scale and balance were observed. In conclusion, PwMS showed a high level of exertion before treatment. Treadmill training was effective in reducing the level of perceived fatigue, with no impact on balance.

Falls prevention and balance rehabilitation in multiple sclerosis: a bi-centre randomised controlled trial

Abstract Purpose: People with Multiple Sclerosis (PwMS) have a high incidence of accidental falls that have a potentially detrimental effect on their daily life participation. The effect of balance specific rehabilitation on clinical balance measures and frequency of falls in PwMS was studied. Method: A bi-centre randomised rater-blinded controlled trial. Participants in both groups received 20 treatment sessions. Participants in the intervention group received treatment aimed at improving balance and mobility. Participants in the control group received treatments to reduce limitations at activity and body function level. Primary measures were frequency of fallers (>1 fall in two months) and responders (>3 points improvement) at the Berg Balance Scale (BBS). Data was analysed according to an intention to treat approach. Results: One hundred and nineteen participants were randomised. Following treatment frequency of fallers was 22% in the intervention group and 23% in the control group, odds ratio (OR) and (confidence limits): 1.05 (0.41 to 2.77). Responders on the BBS were 28% in the intervention group and 33% in the control group, OR = 0.75 (0.30 to 1.91). At follow up ORs for fallers and responders at BBS were 0.98 (0.48 to 2.01) and 0.79 (0.26 to 2.42), respectively. Conclusions: Twenty sessions 2–3 times/week of balance specific rehabilitation did not reduce fall frequency nor improve balance suggesting the need for more frequent and challenging interventions. Implications for Rehabilitation Programs for balance rehabilitation can improve balance but their effects in fall prevention are unclear. Twenty treatments sessions 2/3 times per week did not reduced frequency of falls in MS. The comparison with similar studies suggests that higher intensity of practice of highly challenging balance activities appears to be critical to maximizing effectiveness.

Effects of functional electrical stimulation on reducing falls and improving gait parameters in multiple sclerosis and stroke

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.

Prediction of Falls in Subjects Suffering From Parkinson Disease, Multiple Sclerosis, and Stroke

OBJECTIVE To compare the risk of falls and fall predictors in patients with Parkinson disease (PD), multiple sclerosis (MS), and stroke using the same study design. DESIGN Multicenter prospective cohort study. SETTING Institutions for physical therapy and rehabilitation. PARTICIPANTS Patients (N=299) with PD (n=94), MS (n=111), and stroke (n=94) seen for rehabilitation. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Functional scales were applied to investigate balance, disability, daily performance, self-confidence with balance, and social integration. Patients were followed for 6 months. Telephone interviews were organized at 2, 4, and 6 months to record falls and fall-related injuries. Incidence ratios, Kaplan-Meier survival curves, and Cox proportional hazards models were used. RESULTS Of the 299 patients enrolled, 259 had complete follow-up. One hundred and twenty-two patients (47.1%) fell at least once; 82 (31.7%) were recurrent fallers and 44 (17.0%) suffered injuries; and 16%, 32%, and 40% fell at 2, 4, and 6 months. Risk of falls was associated with disease type (PD, MS, and stroke in decreasing order) and confidence with balance (Activities-specific Balance Confidence [ABC] scale). Recurrent fallers were 7%, 15%, and 24% at 2, 4, and 6 months. The risk of recurrent falls was associated with disease type, high educational level, and ABC score. Injured fallers were 3%, 8%, and 12% at 2, 4, and 6 months. The only predictor of falls with injuries was disease type (PD). CONCLUSIONS PD, MS, and stroke carry a high risk of falls. Other predictors include perceived balance confidence and high educational level.

Validation of the Arm Profile Score in assessing upper limb functional impairments in people with multiple sclerosis

Background: Although upper limb (UL) impairments are widespread in people with Multiple Sclerosis (pwMS), there is limited quantitative evidence concerning their specific features. The aim of this study is to validate a synthetic measure based on kinematic data to define the degree of deviation from a physiologic pattern during the “hand to mouth” (HTM) task. Methods: Twenty pwMS (mean age 51.2 SD 11.1) years, Expanded Disability Status Scale (EDSS) score in the range 2–6.5, underwent a kinematic analysis of the HTM task using a motion capture system. Spatio‐temporal parameters and synthetic indexes (Arm Variable Score, AVS and Arm Profile Score, APS) were calculated and compared with those of age‐matched healthy individuals. Kinematic data were correlated with the EDSS score and clinical tests such as the Nine Hole Peg Test (NHPT) and hand‐grip strength (HGS). Findings: PwMS exhibit reduced velocity, increased movement duration, sway of adjusting and frequency of direction changes as well as higher APS values (15.4° vs. 8.6°, P < 0.001) with respect to controls due to alterations in trunk flexion‐extension, shoulder abduction‐adduction, flexion‐extension and rotation and elbow flexion‐extension. Moderate‐to‐large correlations were found between APS and EDSS (rho = 0.609, P < 0.001), NHPT (rho = 0.468, P = 0.03) and HGS (rho = −0.627 P < 0.001). Interpretation: The kinematic analysis of HTM provides useful information in quantifying UL impairments in pwMS. The APS index appears suitable to represent UL movement deviations from the physiological pattern in pwMS and to assess disease progression or effectiveness of pharmacologic and rehabilitative treatments effectiveness. HighlightsCharacterized of upper limbs kinematic patterns in Multiple Sclerosis peopleDefined deviation degree from normal pattern with a kinematic synthetic measureInvestigated correlation between the synthetic measure and clinical scores

Cardiac autonomic function during postural changes and exercise in people with multiple sclerosis: A cross-sectional study

BACKGROUND People with multiple sclerosis (PwMS) often develop an autonomic dysfunction (AD), which onset should be assessed early at a subclinical level, as it may interfere with pharmacological treatments and exercise. OBJECTIVE To evaluate basal cardiac autonomic tone, its modulations during sit-to-stand, sub-maximal exercise and recovery in PwMS without clinical overt AD and its relationships with fatigue perception. METHODS Twenty-three PwMS (55 ± 8 yrs [mean ± SD]; EDSS score 5.7 ± 1.3) and 20 age-matched healthy controls (HC; 55 ± 8yrs) were enrolled. ECG was digitally acquired during:1) sitting at rest (low sympathetic activation); 2) standing (light sympathetic activation); and 3) during light exercise (moderate sympathetic activation) and recovery. Parasympathetic and sympatho-vagal parameters of heart rate (HR) variability in time and frequency domains were calculated from beat series. RESULTS HR was slightly but not significantly higher in PwMS compared to HC in all experimental conditions. Parasympathetic indexes were significantly lower (p < 0.05) in PwMS compared to HC during baseline sitting and post-exercise recovery, whereas sympathovagal parameters were similar in both groups. No correlation between autonomic tone and perceived fatigue was observed. CONCLUSION Parasympathetic tone appears to be impaired in PwMS basal and post-exercise conditions, but not during postural challenge and exercise. In addition, AD does not affect perceived fatigue.