A New Technique to Improve the Operation of Prosthetic Limbs during Muscle Fatigue

Prosthetic limbs hold a promise to renew the quality of life for the amputee. Neural commands are decoded via a classifier to generate control signals for the prosthetic devices. In the literature, many challenges and limitations have been identified that affect the prosthesis operation. One such drawback is muscle fatigue which degrades the surface electromyogram (sEMG) signals, and consequently, the performance of the deployed classification algorithm declines from 90% to 50% of average accuracy. We used a new technique using the Linear Discrimination Analysis (LDA) algorithm and the muscle synergy-based task discrimination (MSD) algorithm to improve the classification accuracy. In this technique, during muscles contraction/fatigue, we used the LDA algorithms in the beginning and the MSD algorithms later. The applied technique exhibited better movement classification performance during normal and muscle fatigue conditions. However, more work needs to be done to effectively solve the muscle fatigue problem in prosthesis design

The Effectiveness of Balance Training Exercise in Post Stroke Individuals Using the Neurocom Balance Master® System

A case study was completed on a 51-year-old female who suffered a stroke in 1996 and exhibited left-sided hemiplegia. The case study examined the effects of a six-week balance training program on an individual at least six months post stroke using a force platform system called the NeuroCom Balance Master®. Individuals suffering a stroke often times exhibit deficits in balance due to weakness, sensory loss, impaired righting reflexes, and visuospatial distortion. The goal of the training program was to improve the subject\u27s balance deficits by focusing on areas of symmetrical weight bearing, weight shifting, and coordination of movement. Initial and final assessments were conducted using the NeuroCom Balance Master® and the Tinnetti Assessment Tool to assess any change in the subject\u27s balance. At the conclusion of the six-week training program, the subject improved in areas of static and dynamic balance and the ability to weight shift in the anterior direction and to her hemiparetic left side. The subject\u27s gait pattern also improved in terms of step length, step width, and step speed. Therefore, the results of this study seem to indicate that post stroke individuals of at least six months may have the ability to improve their overall balance with continued postural training. However, further research is necessary to determine the functional outcomes of postural feedback training and the reasons for improvement seen on the NeuroCom Balance Master.

Neural and motor basis of inter-individual interactions

The goal of my Ph.D. work was to investigate the behavioral markers and the brain activities responsible for the emergence of sensorimotor communication. Sensorimotor communication can be defined as a form of communication consisting into flexible exchanges based on bodily signals, in order to increase the efficiency of the inter-individual coordination. For instance, a soccer player carving his movements to inform another player about his intention. This form of interaction is highly dependent of the motor system and the ability to produce appropriate movements but also of the ability of the partner to decode these cues. To tackle these facets of human social interaction, we approached the complexity of the problem by splitting my research activities into two separate lines of research. First, we pursued the examination of motor-based humans\u2019 capability to perceive and \u201cread\u201d other\u2019s behaviors in focusing on single-subject experiment. The discovery of mirror neurons in monkey premotor cortex in the early nineties (di Pellegrino et al. 1992) motivated a number of human studies on this topic (Rizzolatti and Craighero 2004). The critical finding was that some ventral premotor neurons are engaged during visual presentation of actions performed by conspecifics. More importantly, those neurons were shown to encode also the actual execution of similar actions (i.e. irrespective of who the acting individual is). This phenomenon has been highly investigated in humans by using cortical and cortico-spinal measures (for review see, fMRI: Molenberghs, Cunnington, and Mattingley 2012; TMS: Naish et al. 2014; EEG: Pineda 2008). During single pulse TMS (over the primary motor cortex), the amplitude of motor evoked potentials (MEPs) provides an index of corticospinal recruitment. During action observation the modulation of this index follow the expected changes during action execution (Fadiga et al. 1995). However, dozens of studies have been published on this topic and revealed important inconsistencies. For instance, MEPs has been shown to be dependent on observed low-level motor features (e.g. kinematic features or electromyography temporal coupling; Gangitano, Mottaghy, and Pascual-Leone 2001; Borroni et al. 2005; Cavallo et al. 2012) as well as high level movement properties (e.g. action goals; Cattaneo et al. 2009; Cattaneo et al. 2013). Furthermore, MEPs modulations do not seem to be related to the observed effectors (Borroni and Baldissera 2008; Finisguerra et al. 2015; Senna, Bolognini, and Maravita 2014), suggesting their independence from low-level movement features. These contradictions call for new paradigms. Our starting hypothesis here is that the organization and function of the mirror mechanism should follow that of the motor system during action execution. Hence, we derived three action observation protocols from classical motor control theories: 1) The first study was motivated by the fact that motor redundancy in action execution do not allow the presence of a one-to-one mapping between (single) muscle activation and action goals. Based on that, we showed that the effect of action observation (observation of an actor performing a power versus a precision grasp) are variable at the single muscle level (MEPs; motor evoked potentials) but robust when evaluating the kinematic of TMS-evoked movements. Considering that movements are based on the coordination of multiple muscle activations (muscular synergies), MEPs may represent a partial picture of the real corticospinal activation. Inversely, movement kinematics is both the final functional byproduct of muscles coordination and the sole visual feedback that can be extracted from action observation (i.e. muscle recruitment is not visible). We conclude that TMS-evoked kinematics may be more reliable in representing the state of the motor system during action observation. 2) In the second study, we exploited the inter-subject variability inherent to everyday whole-body human actions, to evaluate the link between individual motor signatures (or motor styles) and other\u2019s action perception. We showed no group-level effect but a robust correlation between the individual motor signature recorded during action execution and the subsequent modulations of corticospinal excitability during action observation. However, results were at odds with a strict version of the direct matching hypothesis that would suggest the opposite pattern. In fact, the more the actor\u2019s movement was similar to the observer\u2019s individual motor signature, the smaller was the MEPs amplitude, and vice versa. These results conform to the predictive coding hypothesis, suggesting that during AO, the motor system compares our own way of doing the action (individual motor signature) with the action displayed on the screen (actor\u2019s movement). 3) In the third study, we investigated the neural mechanisms underlying the visual perception of action mistakes. According to a strict version of the direct matching hypothesis, the observer should potentially reproduce the neural activation present during the actual execution of action errors (van Schie et al. 2004). Here, instead of observing an increase of cortical inhibition, we showed an early (120 ms) decrease of intracortical inhibition (short intracortical inhibition) when a mismatch was present between the observed action (erroneous) and the observer\u2019s expectation. As proposed by the predictive coding framework, the motor system may be involved in the generation of an error signal potentially relying on an early decrease of intracortical inhibition within the corticomotor system. The second line of research aimed at the investigation of how sensorimotor communication flows between agents engaged in a complementary action coordination task. In this regard, measures of interest where related to muscle activity and/or kinematics as the recording of TMS-related indexes would be too complicated in a joint-action scenario. 1) In the first study, we exploited the known phenomenon of Anticipatory Postural Adjustments (APAs). APAs refers to postural adjustments made in anticipation of a self- or externally-generated disturbance in order to cope for the predicted perturbation and stabilize the current posture. Here we examined how observing someone else lifting an object we hold can affect our own anticipatory postural adjustments of the arm. We showed that the visual information alone (joint action condition), in the absence of efference copy (present only when the subject is unloading by himself the object situated on his hand), were not sufficient to fully deploy the needed anticipatory muscular activations. Rather, action observation elicited a dampened APA response that is later augmented by the arrival of tactile congruent feedback. 2) In a second study, we recorded the kinematic of orchestra musicians (one conductor and two lines of violinists). A manipulation was added to perturb the normal flow of information conveyed by the visual channel. The first line of violinist where rotated 180\ub0, and thus faced the second line. Several techniques were used to extract inter-group (Granger Causality method) and intra-group synchronization (PCA for musicians and autoregression for conductors). The analyses were directed to two kinematic features, hand and head movements, which are central for functionally different action. The hand is essential for instrumental actions, whereas head movements encode ancillary expressive actions. During the perturbation, we observed a complete reshaping of the whole patterns of communication going in the direction of a distribution of the leadership between conductor and violinists, especially for what regards head movements. In fact, in the perturbed condition, the second line acts as an informational hub connecting the first line to the conductor they no longer can see. This study evidences different forms of communications (coordination versus synchronization) flowing via different channels (ancillary versus instrumental) with different time-scales

Balance evaluation techniques and physical therapy in post-stroke patients: A literature review

A stroke (cerebrovascular accident – CVA) is a significant social–economic issue. Approximately 15–30% of all patients develop life-long disability, 20% require over 3 months of specialized care in healthcare institutions, and the majority of the patients never recover the ability to maintain a proper vertical position. Such CVA sequelae as balance disturbances not only negatively affect patients’ daily physical activity, but also result in social isolation. A number of standardized clinical scales, tests, and instrumental examination techniques have been proposed for evaluating not only post-CVA balance function, but also any changes in this function following various interventions. Even though scientific literature lists numerous methods and instruments for the improvement of balance after a CVA, not all of them are equally effective, and there have been rather controversial evaluations of some techniques. Nevertheless, the application of the majority of the techniques as complementary or alternative measures to traditional physical therapy (PT) frequently yields better results

Aquatic Physical Therapy Techniques for Neurologic Symptoms

Aquatic physical therapy (APT) has been defined as a comprehensive therapeutic approach that benefits a person physically, emotionally, and psychologically through active participation in an individualized pool program. The purpose of this study is to review the literature regarding aquatic therapy and neurologic symptoms to provide physical therapy students and professionals with techniques and exercises that can be used to treat persons who present with neurologic disorders. The history of hydrotherapy, the relative properties of water, the contraindications, precautions, and indications of aquatic exercise, and the definitions and treatments of specific neurologic symptoms will be addressed. The symptom specific techniques and exercises presented will assist physical therapists and students in implementing aquatic neurorehabilitation into their practice

Effects of Combined Exercise Training on Balance of Hemiparetic Stroke patients

INTRODUCTION: A stroke occurs as a result of brain damage caused by cerebral infarction or hemorrhage. The majority, 73~88%, of cerebral infarction patients have impaired sensory motor ability on the side opposite to the brain damage appearing as hemiplegia of the arms and legs or either. Most survivors of stroke have decreased capacity to perform activities of daily living (ADL) because of a combination of sensory, motor, cognitive and emotional impairments. Of all the possible sensorimotor deficits of stroke, damaged postural control has the greatest impact on ADL independence and gait. Hemiplegic patients have decreased balance control ability. Especially, the postural sway in static positions is more than twice that of healthy subjects of the same age group, which consequences for safety4. Balance is described as the ability to maintain equilibrium in a gravitational field by keeping or returning the center of body mass over its base of support5. Dynamic balance is a voluntary response which maintains the position in response to an external perturbation. AIM OF THE STUDY: To find the effectiveness of combined exercises which consists of aerobic training and functional strengthening exercise over conventional exercises which consists of balance,posture control exercise and gait training in improving balance in hemiparetic stroke patients. OBJECTIVES: 1. To find the effectiveness of combined exercises (functional strengthening exercise and aerobic) in improving the balance in hemiparetic stroke patients. 2. To find the effectiveness of conventional exercises (balance exercise,posture exercise and gait training) in improving balance in hemiparetic stroke patients. 3. To compare the effectiveness of combined exercise versus conventional exercises training in improving balance in hemiparetic stroke patients. MATERIALS AND METHODLOGY: RESEARCH DESIGN: A Pretest-Posttest experimental study consisting of 30 stroke patients were undertaken to investigate the balance of the hemiparetic stroke patients. There are two experimental groups. SELECTION CRITERIA: Inclusion Criteria: 1. Patients with stroke involving in lower extremity. 2. Patient within 6 months of post stroke period. 3. Both sexes. 4. Age group between 35-50 years. 5. Patient who can stand independently without any assistive devices at least for a minute. Exclusion Criteria: 1. Haemodynamically unstable. 2. Patient could not perform functional exercise due to arthritis. 3. Low back pain, with radiating pain and numbness over legs. 4. Cardiovascular and Respiratory conditions impairing aerobic training. 5. Patient who have uncontrolled hypertension. 6. Patients who could not follow instructions due to low perceptive abilities, cognitive disorder. 7. Hearing impairment. SAMPLE SIZE AND SAMPLING: Purposive sampling of thirty samples was adopted in this study. A group of 30 subjects who had satisfied the inclusion criteria and exclusion criteria were selected and they were purposively divided into two groups. Group 1 - received combined exercises with aerobics and functional strengthening exercise, Group 2 - received conventional exercises. Setting of Study: Narayana Health, Multi speciality Hospital, Bangalore-99. Duration of the Study: It was an experimental study with the duration of 4 weeks of treatment per subject. RESULTS: As the calculated value is greater than the t table value. Null hypothesis 1 (Ho1) is rejected and research hypothesis 1 (H11) is accepted. As the calculated value is greater than the t table value. Null hypothesis 2 (H02) is rejected and research hypothesis 2 (H12) is accepted. As the calculated value is greater than the t table value. Null hypothesis 1 (H03) is rejected and research hypothesis 3 (H13) is accepted. SUMMARY: In this study, totally 30 subjects of the hemiparetic stroke patients are taken into two experimental groups equally into Combined exercises group (aerobic and functional strengthening exercises) group 1 and conventional exercises group (balance exercises, posture exercises and gait training) group 2 in improving the static and dynamic balance by using the Berg Balance Scale (BBS) and Timed Up and Go test (TUG) as the outcome measuring scale. Based on the results found in this study there are improvements in both the combined exercises, group 1 and conventional exercises, group 2. But, there are significant better improvement in the combined exercises, group 1 than the conventional exercises, group 2. So, the results found are published. CONCLUSIONS: Based on this study combined exercises given to group 1 has shown the improvement in both the static and dynamic balance scores in the hemiparetic stroke patients. Based on this study conventional exercises given to group 2 has shown the improvement in both the static and dynamic balance scores in the hemiparetic stroke patients. Based on this study combined exercise of group 1 had shown the marked improvement in both the static and dynamic balance than the conventional exercises of group 2 in the hemiparetic stroke patients. This suggests that combined exercise training can be prescribed for stroke patients to reduce their risk of falls and lead to independent ADL

Electromyography-Based Control of Lower Limb Prostheses: A Systematic Review

Most amputations occur in lower limbs and despite improvements in prosthetic technology, no commercially available prosthetic leg uses electromyography (EMG) information as an input for control. Efforts to integrate EMG signals as part of the control strategy have increased in the last decade. In this systematic review, we summarize the research in the field of lower limb prosthetic control using EMG. Four different online databases were searched until June 2022: Web of Science, Scopus, PubMed, and Science Direct. We included articles that reported systems for controlling a prosthetic leg (with an ankle and/or knee actuator) by decoding gait intent using EMG signals alone or in combination with other sensors. A total of 1,331 papers were initially assessed and 121 were finally included in this systematic review. The literature showed that despite the burgeoning interest in research, controlling a leg prosthesis using EMG signals remains challenging. Specifically, regarding EMG signal quality and stability, electrode placement, prosthetic hardware, and control algorithms, all of which need to be more robust for everyday use. In the studies that were investigated, large variations were found between the control methodologies, type of research participant, recording protocols, assessments, and prosthetic hardware

Effects of Proprioceptive Neuromuscular Facilitation (PNF) Neck Pattern Over Trunk Specific Exercises on Trunk Control and Balance in Patients with Chronic Stroke: An Experimental study

INTRODUCTION: Cerebral vascular accident provides a base for modern researchers to implement their ideas to bring a resolution in this field and enhance the quality of life in patients. Stroke is a leading cause of death and disability in low and middle income countries including India, largely driven by demographic changes and enhanced by the increasing prevalence of the key modifiable risk factor. The poor are increasingly affected by stroke, because of both the changing population exposures to risk factors and most tragically, not being able to afford the high cost for stroke care. Majority of stroke survivors continue to live with disabilities, and the costs of on-going rehabilitation and long term-care are largely undertaken by family members, which impoverish their families. Like other developing countries, stroke is a fast emerging major problem and a leading cause of death and disability in India. Therefore, it is one of the common life threatening neurological disorder. AIM OF THE STUDY: The aim of the study was to find out the effects of Proprioceptive Neuromuscular Facilitation neck pattern over trunk specific exercises on trunk control and balance in patients with chronic stroke. METHODS: A total of 30 subjects were selected and randomly divided into group A of 15 subjects, who received the proprioceptive neuromuscular facilitation neck pattern exercise along with Trunk specific exercises and group B of 15 subjects, who received Trunk specific exercises. Trunk impairment scale and Berg Balance Scale were used to measure the outcomes. DATA ANALYSIS: The trunk impairment scale test data. The standard deviation for trunk impairment scale of group A is 13.33 and the standard deviation for trunk impairment scale of group B is 11.26 the calculated ‘t’ value is 3.45 where the table value was 2.048 and finally the p value is 0.001795. The standard deviation for Berg Balance scale of group A is 33.36 and the standard deviation of group B is 30.7. The calculated ‘t’ value is 3.45 where the table value was 2.048 and finally the ‘p’ value is 0.001795 and the calculated ‘t’ value is 2.5 where the table value is 2.048 and finally the ’p’ value is 0.001795. RESULT: The result shows significant difference between the pre and post therapy scores when evaluated with Trunk Impairment and Berg Balance Scale. A statistically significant improvement was obtained in group A on trunk control and balance in patients with chronic stroke. (P <0.05). CONCLUSION: The study concluded that there is a significant effects of Proprioceptive Neuromuscular Facilitation Neck pattern over trunk specific exercises on trunk control and balance

Effect of Heavy Lifting with a Head Strap on the Pelvic Floor across the Menstrual Cycle

Background: Pelvic organ prolapse (POP) occurs in 10% of women in Nepal, even 6% of nulliparous women have symptomatic POP.1 This may be linked to the heavy lifting tasks performed by women using a head strap.2 This study explored the impact of hormonal changes on the pelvic floor when performing these tasks during each phase of the menstrual cycle. Methods: The study included 22 female Nepali participants with a mean age of 27.4(3.6) years; all were from rural villages and frequently carried with a head strap. Using intravaginal pressure transducers (IVT), the mean change in intraabdominal pressure (IAP) was found to be 37.1(4.3) cmH20 when lifting a load with a mean weight of 19.8(3.2)kg using a head strap. Lifting tasks were simulated with isometric ballistic lifts against a head strap secured to the plith with the participant lying supine. The mean increase in IAP from rest was 31.6(2.1)cmH20. Displacement of the pelvic floor was measured by transperineal ultrasound. Mean displacement of the pelvic floor at ovulation was 5.1(0.4)mm and a mean of 5.9(0.4)mm during the early follicular phase (p 0.03). Conclusion: during the early follicular phase, when basal body temperature and beta estrogen are lowest, the compliance of the pelvic floor is greatest. Repetitive lifting during this time may predispose some woman to POP