A wearable system for visual cueing gait rehabilitation in Parkinson's disease: a randomized non-inferiority trial.

BACKGROUND: Gait disturbances represent one of the most disabling features of Parkinson's disease (PD). AIM: The aim of this study was to evaluate the non-inferiority of a new wearable visual cueing system (Q-Walk) for gait rehabilitation in PD subjects, compared to traditional visual cues (stripes on the floor). DESIGN: Open-label, monocentric, randomized controlled non-inferiority trial. SETTING: Outpatients. POPULATION: Patients affected by idiopathic PD without cognitive impairment, Hoehn and Yahr stage II-IV, Unified Parkinson's Disease Rating Scale motor section III ≥2, stable drug usage since at least 3 weeks. METHODS: At the enrollment (T0), all subjects underwent a clinical/functional evaluation and the instrumental gait and postural analysis; then they were randomly assigned to the Study Group (SG) or Control Group (CG). Rehabilitation program consisted in 10 consecutive individual sessions (5 sessions/week for 2 consecutive weeks). Each session included 60 minutes of conventional physiotherapy plus 30 minutes of gait training by Q-Walk (SG) or by traditional visual cues (CG). Follow-up visits were scheduled at the end of the treatment (T1) and after 3 months (T2). RESULTS: Fifty-two subjects were enrolled in the study, 26 in each group. The within-groups analysis showed a significant improvement in clinical scales and instrumental data at T1 and at T2, compared to baseline, in both groups. According to the between-group analysis, Q-Walk cueing system was not-inferior to the traditional cues for gait rehabilitation. The satisfaction questionnaire revealed that most subjects described the Q-Walk cueing system as simple, motivating and easily usable, possibly suitable for home use. CONCLUSIONS: Data showed that motor rehabilitation of PD subjects performed by means of the new wearable Q-Walk cueing system was feasible and as effective as traditional cues in improving gait parameters and balance. CLINICAL REHABILITATION IMPACT: Wearable devices can act as an additional rehabilitation strategy for long-term and continuous care, allowing patients to train intensively and extensively in household settings, favoring a tailor-made and personalized approach as well as remote monitoring.

Relevance of evaluating the rate of torque development in ballistic contractions of submaximal amplitude.

OBJECTIVE: The neuromuscular quickness capacity can be assessed by calculating the rate of torque development (RTD) during ballistic contractions of maximal (RTDmaximal) or submaximal (RTDsubmaximal) amplitudes. In a series of ballistic contractions of submaximal amplitudes, the RTD scaling factor (RTD-SF) represents the slope of the linear regression between achieved peak torques and the corresponding RTD. First we investigated whether the RTD-SF contributes to the prediction, together with maximal voluntary torques (MVT), of the RTDmaximal. Then, we evaluated the agreement between the z-scores of RTDmaximal and RTDsubmaximal. APPROACH: The MVT was obtained for the quadriceps and hamstrings muscles of 22 elite young soccer players. RTD-SF was quantified in a series of ballistic contractions of submaximal and maximal amplitudes. RTDsubmaximal was estimated from the regression relationship between the peak torques and the corresponding RTD. MAIN RESULTS: MVT, RTD-SF and y -intercept in total accounted for 76.9 and 61.2% of the variance in RTDmaximal in quadriceps and hamstrings, respectively. Specifically, RTD-SF accounted for 13.7% and 18.7% of the variance in RTDmaximal, respectively. Generally, the agreement between the z-scores of RTDmaximal and RTDsubmaximal was poor both in quadriceps and hamstrings. SIGNIFICANCE: These results suggest that RTD-SF may have a functional relevance in the relationship between MVT and RTDmaximal and influence the amount of torque that can be achieved in a quick muscle contraction. Moreover, evaluating the RTDsubmaximal does not provide results that are interchangeable with RTDmaximal. Thus, evaluating the RTD across the whole range of torque could provide additional meaningful information about neuromuscular quickness.

Interlimb Asymmetries Identified Using the Rate of Torque Development in Ballistic Contraction Targeting Submaximal Torques.

Evaluating the rate of torque development (RTD) in isometric ballistic contraction targeting submaximal torques is usually overlooked in the literature. In a series of isometric ballistic contractions targeting a range of submaximal torque values, there is a linear relationship between the peak torque and the peak RTD obtained in each contraction. RTD scaling factor (RTD-SF) represents the slope of this relationship. In this study, we investigated the prevalence of interlimb asymmetry in the RTD-SF and in the RTD calculated across submaximal torques. Furthermore, we compared these asymmetry indices with those calculated adopting more classical approaches, such as ballistic contraction targeting maximal torque and isokinetic concentric conditions. Quadriceps and hamstrings strength was evaluated in both limbs of elite under 17 and under 19 soccer players (20 males, 17 ± 1 years). Participants performed three concentric isokinetic contractions at 240°/s and a series of isometric ballistic contractions targeting from 20 to 100% of maximal isometric torque. The interlimb difference was calculated for each parameter and players presenting an interlimb difference >15% were identified. A total of 40% (for quadriceps) and 60% (for hamstring) of players showed an interlimb asymmetry in isometric RTD for at least 50% of submaximal torque range. The RTD-SF was able to identify more players with asymmetry than the classical isokinetic tests. However, isokinetic and isometric indices of asymmetry were in general poorly or not correlated with each other. Most players presented an interlimb asymmetry in RTD for a wide part of the torque range and the adopted protocol was able to highlight important interindividual differences. Furthermore, players showed a large prevalence of RTD-SF asymmetry in both quadriceps and hamstrings. It is still to be determined if these asymmetries are functionally relevant. Nevertheless, the adopted protocol provided meaningful information for identifying interlimb asymmetries that could not be gathered when adopting the classical method of ballistic contractions targeting only maximal torques.

Acute effects of high-frequency microfocal vibratory stimulation on the H reflex of the soleus muscle. A double-blind study in healthy subjects.

This study in healthy subjects examined the effects of a system delivering focal microvibrations at high frequency (Equistasi®) on tonic vibration stimulus (TVS)-induced inhibition of the soleus muscle H reflex. Highfrequency microvibrations significantly increased the inhibitory effect of TVS on the H reflex for up to three minutes. Moreover, Equistasi® also significantly reduced alpha-motoneuron excitability, as indicated by the changes in the ratio between the maximumamplitude H reflex (Hmax reflex) and the maximumamplitude muscle response (Mmax response); this effect was due to reduction of the amplitude of the H reflex because the amplitude of muscle response remained unchanged. The present findings indicate that Equistasi® has a modulatory effect on proprioceptive reflex circuits. Therefore, Equistasi® might interfere with some mechanisms involved in both physiological and pathophysiological control of movement and of posture.