First you have to cure my spasticity that prevents a free swinging lower leg and straighten my left foot so it doesn't angle out at 15 degrees. This is cherry picking less damaged brains.
Rest the brain to learn new gait patterns after stroke
Journal of NeuroEngineering and Rehabilitation volume 21, Article number: 192 (2024)
Abstract
Background
The ability to relearn a lost skill is critical to motor recovery after a stroke. Previous studies indicate that stroke typically affects the processes underlying motor control and execution but not the learning of those skills. However, these studies could be confounded by the presence of significant motor impairments. Furthermore, prior research involving the upper extremity indicates that stroke survivors have an advantage in offline motor learning when compared with controls. However, this has not been examined using motor acuity tasks (i.e., tasks focusing on the quality of executed actions) that have direct functional relevance to rehabilitation.
Objective
Investigate how stroke affects leg motor skill learning during walking in stroke survivors.
Methods
Twenty-five participants (10 stroke; 15 controls) were recruited for this prospective, case-control study. Participants learned a novel foot-trajectory tracking task on two consecutive days while walking on a treadmill. The task necessitated greater hip and knee flexion during the swing phase of the gait.(Which I can't do due to spasticity!) Online learning was measured by comparing tracking error at the beginning and end of each practice session, offline (rest-driven) learning was measured by comparing the end of the first practice session to the beginning of the second, and retention was measured by comparing the beginning of the first practice session to the beginning of the second. Online learning, offline learning, and retention were compared between the stroke survivors and uninjured controls.
Results
Stroke survivors improved their tracking performance on the first day (p = 0.033); however, the amount of learning in stroke survivors was lower in comparison with the control group on both days (p ≤ 0.05). Interestingly, stroke survivors showed higher offline learning gains when compared with uninjured controls (p = 0.011).
Conclusions
Even stroke survivors with no perceivable motor impairments have difficulty acquiring new motor skills related to walking, which may be related to the underlying neural damage caused at the time of stroke. Furthermore, stroke survivors may require longer training with adequate rest to acquire new motor skills.
Background
Stroke is a major cause of adult disability worldwide, affecting millions of people each year [1, 2]. Common motor impairments after stroke include weakness on one side of the body [3], difficulty coordinating movements [4, 5], and loss of balance [6]. These impairments often result in disabilities that restrict the mobility and independence of stroke survivors in their daily activities, which in turn highlights the need for effective rehabilitation techniques that can improve walking ability. Current approaches to gait recovery after stroke often involve task-specific training with assistive devices and interactive technologies [7, 8]. However, despite their effectiveness, these methods are no more beneficial than conventional rehabilitation in most clinical trials [9,10,11]. Therefore, there is a critical need for new therapies that can facilitate gait recovery after stroke.
A key to developing effective rehabilitation interventions after stroke is through the application of motor learning principles. Although the importance of incorporating motor learning principles into stroke rehabilitation programs has been repeatedly emphasized [12, 13], there still remains a large gap in our understanding of how learning and rehabilitation processes are interlinked in clinical populations [14]. There is some evidence that acquiring new skills can activate neuroplastic mechanisms in the brain and that the process of learning a new motor skill shares similarities with relearning lost motor skills following a stroke [12, 15]. Therefore, studying motor learning deficits after a stroke can provide a better understanding of the specific mechanisms of neurophysiological recovery, which could aid in the development of more effective interventions.
However, the effect of stroke on motor skill learning is difficult to estimate, as there is limited research on this topic and previous research has yielded conflicting results. For example, some studies suggest that stroke primarily affects the processes underlying motor control and execution, while leaving the learning of motor skills intact [16,17,18,19]. However, a recent study revealed that the extent of motor learning deficits following a stroke is dependent on the severity of motor impairment [20]. It is important to note that a major challenge in establishing evidence of learning deficits is that performance deficits can be misinterpreted as learning deficits [21, 22]. This is supported by the observation that error-based learning capacity—learning driven by error relative to a desired action or goal—in stroke survivors is comparable to neurologically intact adults when motor execution deficits are controlled for during the experiment [16, 19]. However, many of these prior studies, for good reasons, have focused on goal or action selection (i.e., where to move to or what movement can achieve the chosen goal) with less emphasis on motor acuity (i.e., the quality of the executed movements) [23]. More importantly, the experimental tasks are often restricted to a single degree of freedom (DOF) movement, thereby making it challenging to generalize these findings to complex multi-DOF movements (e.g., gait) and limiting their functional relevance to rehabilitation.
Another challenge in determining the effect of stroke on motor skill learning is that learning is mediated by both online and offline processes that may be differentially affected by stroke. Specifically, changes in performance can be due to learning during practice or from periods of rest between practice when information is consolidated and committed to long-term memory [24]. Changes due to practice are typically measured by evaluating the change in performance from the beginning to the end of training (i.e., online learning), while consolidation is measured by evaluating changes in performance from the end of training to the beginning of a follow-up session conducted in the following days (i.e., offline gains/learning) [25]. The summation of these two processes can be evaluated by retention of learning, which is measured as a change from the beginning of training to the follow-up session. Previous studies have shown that stroke survivors improve their performance on motor skills following a period of sleepful rest, while uninjured controls reduce their performance. Interestingly, these same learning gains are not observed in stroke survivors who rest for an equivalent time interval without sleep [26,27,28]. As such, it seems possible that stroke survivors undergoing interventions involving learning may benefit from periods of sleep between practice sessions. Furthermore, it is possible that this advantage in offline gains is masking online deficits in studies that only measure retention. However, as mentioned above, these contributions of offline gains to skill learning in stroke survivors have not been investigated in complex, lower-extremity tasks that have relevance to gait rehabilitation. As a result, it is currently unclear how stroke affects motor learning and whether learning deficits are present in individuals with minimal impairment when performing functional lower-extremity tasks such as walking.
Therefore, the purpose of this study was to evaluate the extent of motor learning deficits in chronic stroke survivors using a functional leg motor skill learning task. To minimize the impact of paresis/weakness on our findings, we specifically recruited stroke survivors with minimal impairment. To comprehensively understand the effect of stroke on motor learning, we examined both online (i.e., changes that occur during practice within the same day) and offline (i.e., changes that occur after practice during periods of no practice between days) learning. To address the issue of task relevance to day-to-day activities, the task required participants to learn a gait pattern that required 30% greater hip and knee flexion during the swing phase, which has been previously shown to be highly relevant in rehabilitation training for addressing stiff knee gait after stroke [29]. We hypothesized that stroke survivors with mild motor impairments would exhibit significant deficits in both online and offline learning and retention of motor skills during walking when compared with uninjured controls.
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