[ARTICLE] Walking Training with a Weight Support Feedback Cane Improves Lower Limb Muscle Activity and Gait Ability in Patients with Chronic Stroke: A Randomized Controlled Trial – Full Text

Abstract

Background

Induction of proper weight transfer to the affected lower limb should be considered the most essential factor for successful stroke cane gait training. This study aimed to investigate the effect of walking training with a weight support feedback cane on lower limb muscle activity and gait ability of chronic stroke patients.

Material/Methods

Thirty stroke patients were randomized into 2 groups: a weight support feedback cane gait training group (WSFC group, n=15) and a conventional cane gait training group (CC group, n=15). All subjects were enrolled in standard rehabilitation programs for 4 weeks. Additionally, the WSFC group participated in WSFC gait training and the CC group participated in conventional cane gait training for 4 weeks. During WSFC gait training, the weight support rate loaded on the cane was reduced by 10% every week from 60% to 30% based on the measured initial cane dependence, while the CC group participated in conventional cane gait training with verbal instruction to reduce cane dependence. Lower limb muscle activity and gait ability were measured using wireless surface electromyography and a 3-axis accelerometer during walking.

Results

The WSFC group showed significantly greater improvement than the CC group in lower limb muscle activity and gait ability (P<0.05).

Conclusions

Cane gait training significantly improved lower limb muscle activity and gait ability in stroke regardless of the training method; however, the addition of real-time weight support feedback to cane gait training appears to provide further benefit compared with conventional cane gait training in chronic stroke patients.

Background

Stroke is classified as ischemic, caused by blockage of blood vessels supplying blood to the brain, and hemorrhagic, caused by rupture of blood vessels in the brain [1]. Stroke is a leading cause of death and dysfunction worldwide [2] and in general, it is associated with muscle weakness, decreased sensation, decreased cognitive function, depression, and decreased quality of life [3–5]. In particular, muscle weakness in the affected side causes overuse and asymmetrical weight shift to the non-affected lower limb [6], leading to an increased risk of falls, decreased independence in daily life, decreased postural control, and asymmetrical walking pattern [7,8]. Therefore, rehabilitation for symmetrical weight transfer and gait enhancement is fundamental to improve the independence and quality of life of patients with stroke [9,10].

In clinical practice, various assistive devices, such as parallel bars, walker, and cane, are used for balance and gait training of stroke patients. Among them, a cane can help to increase the base of support for stroke patients to provide postural stability and improves weight transfer ability in the standing position and walking [11–13]. Using a cane during the single-limb stance phase helps to retrain weight transfer to the affected lower limb and provides tactile information about the ground [14,15]. In addition, using a cane can contribute to stable postural control by controlling the rapid movement of the center of gravity during the stance phase [16]. Park reported that the use of a cane is effective in improving the weight support rate of the affected lower limb in patients with stroke [17]. Moreover, Boonsinsukh et al reported that cane training with auditory feedback according to the weight support rate of the affected lower limb leads to improvement of muscle activity in the affected tensor fasciae latae and vastus medialis [18]. In contrast, several studies have shown that the use of a cane in the early rehabilitation period caused a decrease in muscle activity of the affected lower limb [12,19] and it interferes with symmetrical weight distribution, which ultimately interferes with acquisition of independent gait ability [20,21]. Although the main purpose of using a cane is to help weight distribution to the affected lower limb, improper use of a cane can contribute to an asymmetrical gait pattern by inducing excessive weight support to the non-affected lower limb [16].

Therefore, for successful cane gait training, induction of proper weight transfer to the affected lower limb should be considered the most essential factor [6,22]. However, in clinical practice, it is difficult to quantitatively monitor the weight carried on the cane during cane gait training due to technical problems. Additionally, it is difficult for patients to receive accurate feedback on weight support on the paretic lower limb during cane gait training [23]. Moreover, there is insufficient information on the effects of progressive weight support induction on the affected lower limb during cane gait training on muscle activity and gait in patients with stroke.

Thus, this study aimed to investigate the effect of weight support feedback cane gait training that provided real-time feedback of the user’s weight support loaded on a cane on the lower limb muscle activity and gait ability of patients with chronic stroke. We hypothesized that 4 weeks of weight support feedback cane gait training would show improvements in lower limb muscle activity and gait ability in chronic stroke patients. […]

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Figure 2
A weight support feedback cane (WSFC). The WSFC measures the cane dependence by a load cell located at the bottom of the WSFC handle, and the measured cane dependence is displayed on the WSFC handle (A) and smartphone application in real time (B).

[WEB] Personalized Exosuit Uses Ultrasound to Adapt to User’s Needs – Video

By CONN HASTINGS

At Harvard University a team of scientists and engineers developed an exosuit that uses ultrasound to measure muscle activity. The capability allows for rapid calibration of the suit for users’ needs. The soft wearable device continuously assists when walking or running, reducing the energy required to perform these tasks, which could be very useful for patients with neurological issues or muscular dystrophy. By directly measuring muscle dynamics, the suit provides activity- and user-specific assistance, bringing such wearable technologies a step closer to fruition.

Wearable ‘exosuits’ have significant potential in assisting those with mobility issues by providing supplemental power when a wearer is walking or running. Medgadget has featured these technologies in the past. However, at present, it is not straightforward to calibrate an exosuit to optimize for a particular user or for different activities a single user might take part in. For instance, the mechanics of running and walking are quite different and uneven terrain can drastically change the requirements of the exosuit.

Currently, it is typical that hours of fine tuning are required before an exosuit is ready for the needs of a particular user performing a specific task. This is laborious and impractical, and a barrier to the wider adoption of such technology. In response to this, the Harvard researchers designed an exosuit that can directly measure the muscle activity of its wearer as they perform a specific task and then enable rapid customization of the suit so that it fulfills the needs of the user.

“We used ultrasound to look under the skin and directly measured what the user’s muscles were doing during several walking tasks,” said Richard Nuckols, one of the developers of the new exosuit technology, in a Harvard press release. “Our muscles and tendons have compliance which means there is not necessarily a direct mapping between the movement of the limbs and that of the underlying muscles driving their motion.”

The new system consists of a portable ultrasound system that is strapped to the leg of a user, which images the underlying muscle activity. “From these pre-recorded images, we estimated the assistive force to be applied in parallel with the calf muscles to offset the additional work they need to perform during the push off phase of the walking cycle,” said Krithika Swaminathan, another researcher involved in the study.

After just a couple of seconds of walking, the suit can accurately assess the muscle activity. “By measuring the muscle directly, we can work more intuitively with the person using the exosuit,” said Sangjun Lee, another researcher involved creating the device. “With this approach, the exosuit isn’t overpowering the wearer, it’s working cooperatively with them.”

See a video about the technology below.

Study in Science Robotics: Individualization of exosuit assistance based on measured muscle dynamics during versatile walking

Via: Harvard

Conn Hastings

Conn Hastings received a PhD from the Royal College of Surgeons in Ireland for his work in drug delivery, investigating the potential of injectable hydrogels to deliver cells, drugs and nanoparticles in the treatment of cancer and cardiovascular diseases. After achieving his PhD and completing a year of postdoctoral research, Conn pursued a career in academic publishing, before becoming a full-time science writer and editor, combining his experience within the biomedical sciences with his passion for written communication.

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[EU Project] Neuroprosthesis user interface based on residual motor skills and muscle activity in persons with upper limb disabilities

Project description

A novel neuroprosthesis control system

Neuroprosthetic devices employ electrodes to interface with the nervous system and attempt to restore loss of function or movement. Scientists of the EU-funded Neuroprosthesis-UI project propose to develop a user interface that will allow people with upper limb disabilities to control the neuroprosthesis using residual motor skills. This interface will comprise different sensors to capture muscle contraction, and with the help of machine learning, it will decode user input into movement intention. This hybrid system will assist patients with upper limb disabilities such as spinal cord injury, stroke and multiple sclerosis in performing activities of daily life independently.Hide the project objective

Objective

In this project, I will develop a user interface that will allow persons with upper limb disabilities to control neuroprosthesis using their residual motor skills. This interface will consist of inertial sensors (IMU) and electromyography (EMG) that are capable of capturing movements and muscle contraction that even persons with high tetraplegia still can control. The interface will also be able to learn different inputs, customizing the system for each user. This requires techniques of machine learning, making it flexible and indicated for users with different upper limb disabilities, such as spinal cord injury, stroke and multiple sclerosis. The machine learning techniques will classify the user inputs into desired commands, working as an intention decoder. The interface will be used to control a hybrid upper limb neuroprosthesis based on surface functional electrical stimulation (FES) and a semi passive mechanical orthosis. The system will allow users to perform activities of daily life independently. To my knowledge, such a hybrid system with FES, and controlled by an interface based on IMUs, EMG and machine learning techniques is novel. I will be working with Christine Coste, an expert in neuroprosthesis for disabled persons, and her interdisciplinary team, which consist of engineers and health professionals with vast experience in neurorehabilitation. This fellowship will enable the transfer of knowledge between her team and me through experiments with real patients and mutual training. I can contribute to the team with my expertise in machine learning and control, whereas they have vast access to patients, medical doctors, mechanical designers, electrical stimulators and sensors. This project is going to be an important step in my career as expand my network in Europe, develop my skills as a biomedical engineer and improve my research experience towards becoming a world-leading expert in neurorehabilitation engineering.

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[Abstract] Changes in lower limb muscle activity after walking on a split-belt treadmill in individuals post-stroke

Abstract

Background: There is growing evidence that stroke survivors can adapt and improve step length symmetry in the context of split-belt treadmill (SBT) walking. However, less knowledge exists about the strategies involved for such adaptations. This study analyzed lower limb muscle activity in individuals post-stroke related to SBT-induced changes in step length.

Methods: Step length and surface EMG activity of six lower limb muscles were evaluated in individuals post-stroke (n=16) during (adaptation) and after (after-effects) walking at unequal belt speeds.

Results: During adaptation, significant increases in EMG activity were mainly found in proximal muscles (p⩽0.023), whereas after-effects were observed particularly in the distal muscles. The plantarflexor EMG increased after walking on the slow belt (p⩽0.023) and the dorsiflexors predominantly after walking on the fast belt (p⩽0.017) for both, nonparetic and paretic-fast conditions. Correlation analysis revealed that after-effects in step length were mainly associated with changes in distal paretic muscle activity (0.522⩽ r ⩽0.663) but not with functional deficits. Based on our results, SBT walking could be relevant for training individuals post-stroke who present shorter paretic step length combined with dorsiflexor weakness, or individuals with shorter nonparetic step length and plantarflexor weakness.

Source: Changes in lower limb muscle activity after walking on a split-belt treadmill in individuals post-stroke

[ARTICLE] Influence of mental practice on upper limb muscle activity and activities of daily living in chronic stroke patients – Full Text PDF

[Purpose] The aim of this study was to determine the effects of mental practice on muscle activity of the upper extremity and performance of daily activities in chronic stroke patients.

[Subjects and Methods] In this research, mental practice was conducted by 2 chronic hemiplegic stroke patients. Mental practice was conducted 30 minutes a day, 5 times a week, for 2 weeks. Evaluation was conducted 4 times before and after intervention. Muscle activity was measured using a surface electromyogram test, and the Modified Barthel Index was used to measure changes in the ability to carry out daily activities.

[Results] Both the muscle activity of the upper extremity and capability to perform daily activities showed improved outcomes after mental practice was conducted.

[Conclusion] Through this research, mental practice was proven to be effective in improving the muscle activity of upper extremity and capability to perform daily activities in chronic hemiplegic stroke patients.

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Source: Influence of mental practice on upper limb muscle activity and activities of daily living in chronic stroke patients