Implicit Motor Sequence Learning and Working Memory Performance Changes Across the Adult Life Span Performance on a Functional Motor Task Is Enhanced by Sleep in Middle-Aged and Older Adults Motor performance and motor learning as a function of age and fitness. Can a single session of motor imagery promote motor learning of locomotion in older adults? A randomized controlled trial A Single Bout of Exercise Improves Motor Memory Sleep Enhances Learning of a Functional Motor Task in Young Adults Effects of simultaneously performed cognitive and physical training in older adults Neural substrates underlying stimulation-enhanced motor skill learning after stroke. Enhanced motor skill acquisition in the non-dominant upper extremity using intermittent theta burst stimulation and transcranial direct current stimulation Multidimensional Motor Sequence Learning Is Impaired in Older But Not Younger or Middle-Aged Adults Impact of Exercise to Improve Gait Efficiency on Activity and Participation in Older Adults With Mobility Limitations: A Randomized Controlled Trial Developmental contributions to motor sequence learning Not only cardiovascular, but also coordinative exercise increases hippocampal volume in older adults Time rather than sleep appears to enhance off-line learning and transfer of learning of an implicit continuous task Short-term motor learning through non-immersive virtual reality task in individuals with down syndrome Effectiveness of knowledge of result and knowledge of performance in the learning of a skilled motor activity by healthy young adults A Single Bout of High-Intensity Interval Training Improves Motor Skill Retention in Individuals With Stroke Motor Imagery Training on Muscle Strength and Gait Performance in Ambulant Stroke Subjects-A Randomized Clinical Trial. Acute exercise improves motor memory: Exploring potential biomarkers
Although implicit motor sequence learning is rather well understood in young adults , effects of aging on this kind of learning are controversial . There is first evidence that working memory ( WM ) might play a role in implicit motor sequence learning in young adults as well as in adults above the age of 65 . However , the knowledge about the development of these processes across the adult life span is rather limited . As the average age of our population continues to rise , a better underst and ing of age-related changes in motor sequence learning and potentially mediating cognitive processes takes on increasing significance . Therefore , we investigated aging effects on implicit motor sequence learning and WM . Sixty adults ( 18–71 years ) completed verbal and visuospatial n-back tasks and were trained on a serial reaction time task ( SRTT ) . R and omly varying trials served as control condition . To further assess consolidation indicated by off-line improvement and reduced susceptibility to interference , reaction times ( RTs ) were determined 1 h after initial learning . Young and older but not middle-aged adults showed motor sequence learning . Nine out of 20 older adults ( compared to one young/one middle-aged ) exhibited some evidence of sequence awareness . After 1 h , young and middle-aged adults showed off-line improvement . However , RT facilitation was not specific to sequence trials . Importantly , susceptibility to interference was reduced in young and older adults indicating the occurrence of consolidation . Although WM performance declined in older participants when load was high , it was not significantly related to sequence learning . The data reveal a decline in motor sequence learning in middle-aged but not in older adults . The use of explicit learning strategies in older adults might account for the latter result Background and Purpose : Although sleep has been shown to enhance motor skill learning , it remains unclear whether sleep enhances learning of a functional motor task in middle-aged and older individuals . The purpose of this study was to examine whether sleep enhances motor learning of a functional motor task in middle-aged and older adults . Methods : Twenty middle-aged and 20 older individuals were r and omly assigned to either the sleep condition or the no-sleep condition . Participants in the sleep condition practice d a novel walking task in the evening , and returned the following morning for retesting . Participants in the no-sleep condition practice d the walking task in the morning and returned the same day in the evening for a retest . Outcome measures included time around the walking path and spatiotemporal gait parameters . Results : Only the middle-aged and older adults in the sleep condition demonstrated significant off-line improvement in performance , measured as a decline in time to walk around the novel path and improvement in spatiotemporal gait parameters . The middle-aged and older adults in the no-sleep condition failed to demonstrate off-line improvements in performance of this functional task . Conclusions : This is the first study to provide evidence that sleep facilitates learning a clinical ly relevant functional motor task in middle-aged and older adults . Because many neurologic conditions occur in the middle-aged and older adults and sleep issues are very prevalent in many neurologic conditions , it is imperative that physical therapists consider sleep as a factor that may impact motor learning and recovery in these individuals . Video Abstract available . ( See Video , Supplemental Digital Content 1 , http://links.lww.com/JNPT/A73 ) for more insights from the authors Past studies have shown that electroencephalographic alpha activity increases as people learn to perform a novel motor task . Additionally , it has been suggested that motor performance and learning decline as people age beyond 60 years , and it has been hypothesized that physical fitness may attenuate this decline through its impact on the cerebral environment . This study was design ed to replicate past research by assessing changes in alpha activity as a function of learning and to extend past research by examining differences in motor performance , motor learning , and alpha activity as a function of age and fitness . VO2max was assessed in 41 older ( ages 60 - 80 years ) and 42 younger ( ages 20 - 30 years ) participants . Participants were r and omly assigned to experimental or control conditions , which differed in the amount of practice received . Participants performed trials on the mirror star trace on both an acquisition and a retention day . Results indicated that younger participants performed better and had greater learning than older participants . Fitness was not found to impact either performance or learning . Participants in the experimental group improved more than those in the control group and maintained this difference at retention , which suggests that learning occurred . Associated with these improvements in performance capabilities was an increase in alpha power Purpose To investigate the influence of a single session of locomotor-based motor imagery training on motor learning and physical performance . Patients and methods Thirty independent adults aged > 65 years took part in the r and omized controlled trial . The study was conducted within an exercise science laboratory . Participants were r and omly divided into three groups following baseline locomotor testing : motor imagery training , physical training , and control groups . The motor imagery training group completed 20 imagined repetitions of a locomotor task , the physical training group completed 20 physical repetitions of a locomotor task , and the control group spent 25 minutes playing mentally stimulating games on an iPad .  Imagined and physical performance times were measured for each training repetition . Gait speed ( preferred and fast ) , timed-up- and -go , gait variability and the time to complete an obstacle course were completed before and after the single training session . Results Motor learning occurred in both the motor imagery training and physical training groups . Motor imagery training led to refinements in motor planning result ing in imagined movements better matching the physically performed movement at the end of training . Motor imagery and physical training also promoted improvements in some locomotion outcomes as demonstrated by medium to large effect size improvements after training for fast gait speed and timed-up- and -go . There were no training effects on gait variability . Conclusion A single session of motor imagery training promoted motor learning of locomotion in independent older adults .  Motor imagery training of a specific locomotor task also had a positive transfer effect on related physical locomotor performance outcomes Regular physical activity has a positive impact on cognition and brain function . Here we investigated if a single bout of exercise can improve motor memory and motor skill learning . We also explored if the timing of the exercise bout in relation to the timing of practice has any impact on the acquisition and retention of a motor skill .  Forty-eight young subjects were r and omly allocated into three groups , which practice d a visuomotor accuracy-tracking task either before or after a bout of intense cycling or after rest .  Motor skill acquisition was assessed during practice and retention was measured 1 hour , 24 hours and 7 days after practice . Differences among groups in the rate of motor skill acquisition were not significant . In contrast , both exercise groups showed a significantly better retention of the motor skill 24 hours and 7 days after practice . Furthermore , compared to the subjects that exercised before practice , the subjects that exercised after practice showed a better retention of the motor skill 7 days after practice . These findings indicate that one bout of intense exercise performed immediately before or after practicing a motor task is sufficient to improve the long-term retention of a motor skill . The positive effects of acute exercise on motor memory are maximized when exercise is performed immediately after practice , during the early stages of memory consolidation . Thus , the timing of exercise in relation to practice is possibly an important factor regulating the effects of acute exercise on long-term motor memory Background Sleep has been demonstrated to enhance simple motor skill learning “ offline ” in young adults . “ Offline learning ” refers to either the stabilization or the enhancement of a memory through the passage of time without additional practice . It remains unclear whether a functional motor task will benefit from sleep to produce offline motor skill enhancement . Physical therapists often teach clients functional motor skills ; therefore , it is important to underst and how sleep affects learning of these skills . Objective The purpose of this study was to determine whether sleep enhances the learning of a functional motor task . Design A prospect i ve , cross-sectional , repeated- measures design was used . Methods Young participants who were healthy ( N=24 ) were r and omly assigned to either a sleep group or a no-sleep group . The sleep group practice d a novel walking task in the evening and underwent retention testing the following morning , and the no-sleep group practice d the task in the morning and underwent retention testing in the evening . Outcome measures included time around the walking path and spatiotemporal gait parameters . Results Only participants who slept after practicing the novel walking task demonstrated a significant offline improvement in performance . Compared with the no-sleep group , participants in the sleep group demonstrated a significant decrease in the time around the walking path , an increase in t and em velocity , an increase in t and em step length , and a decline in t and em step time . Limitations Time-of-day effect and inability to ensure a certain amount of sleep quantity and quality of participants were limitations of the study . Conclusions This study is the first to provide evidence that sleep facilitates learning clinical ly relevant functional motor tasks . Sleep is an important factor that physical therapists should consider when teaching clients motor skills Background While many studies confirm the positive effect of cognitive and physical training on cognitive performance of older adults , only little is known about the effects of simultaneously performed cognitive and physical training . In the current study , older adults simultaneously performed a verbal working memory and a cardiovascular training to improve cognitive and motor-cognitive dual task performance . Twenty training sessions of 30 minutes each were conducted over a period of ten weeks , with a test session before , in the middle , and after the training . Training gains were tested in measures of selective attention , paired-associates learning , executive control , reasoning , memory span , information processing speed , and motor-cognitive dual task performance in the form of walking and simultaneously performing a working memory task . Results Sixty-three participants with a mean age of 71.8 ± 4.9 years ( range 65 to 84 ) either performed the simultaneous training ( N = 21 ) , performed a single working memory training ( N = 16 ) , or attended no training at all ( N = 26 ) . The results indicate similar training progress and larger improvements in the executive control task for both training groups when compared to the passive control group . In addition , the simultaneous training result ed in larger improvements compared to the single cognitive training in the paired-associates task and was able to reduce the step-to-step variability during the motor-cognitive dual task when compared to the single cognitive training and the passive control group . Conclusions The simultaneous training of cognitive and physical abilities presents a promising training concept to improve cognitive and motor-cognitive dual task performance , offering greater potential on daily life functioning , which usually involves the recruitment of multiple abilities and re sources rather than a single one Motor skill learning is one of the key components of motor function recovery after stroke , especially recovery driven by neurorehabilitation . Transcranial direct current stimulation can enhance neurorehabilitation and motor skill learning in stroke patients . However , the neural mechanisms underlying the retention of stimulation-enhanced motor  skill  learning involving a paretic upper limb have not been resolved . These neural substrates were explored by means of functional magnetic resonance imaging . Nineteen chronic hemiparetic stroke patients participated in a double-blind , cross-over r and omized , sham-controlled experiment with two series . Each series consisted of two sessions : ( i ) an intervention session during which dual transcranial direct current stimulation or sham was applied during motor skill learning with the paretic upper limb ; and ( ii ) an imaging session 1 week later , during which the patients performed the learned motor skill . The motor skill learning task , called the ' circuit game ' , involves a speed/accuracy trade-off and consists of moving a pointer controlled by a computer mouse along a complex circuit as quickly and accurately as possible . Relative to the sham series , dual transcranial direct current stimulation applied bilaterally over the primary motor cortex during motor skill learning with the paretic upper limb result ed in ( i ) enhanced online motor skill learning ; ( ii ) enhanced 1-week retention ; and ( iii ) superior transfer of performance improvement to an untrained task . The 1-week retention 's enhancement driven by the intervention was associated with a trend towards normalization of the brain activation pattern during performance of the learned motor skill relative to the sham series . A similar trend towards normalization relative to sham was observed during performance of a simple , untrained task without a speed/accuracy constraint , despite a lack of behavioural difference between the dual transcranial direct current stimulation and sham series . Finally , dual transcranial direct current stimulation applied during the first session enhanced continued learning with the paretic limb 1 week later , relative to the sham series . This lasting behavioural enhancement was associated with more efficient recruitment of the motor skill learning network , that is , focused activation on the motor-premotor areas in the damaged hemisphere , especially on the dorsal premotor cortex . Dual transcranial direct current stimulation applied during motor skill learning with a paretic upper limb result ed in prolonged shaping of brain activation , which supported behavioural enhancements in stroke patients Individuals suffering from motor impairments often require physical therapy ( PT ) to help improve their level of function . Previous investigations suggest that both intermittent theta burst stimulation ( iTBS ) and bihemispheric transcranial direct current stimulation ( tDCS ) may increase the speed and extent of motor learning/relearning . The purpose of the current study was to explore the feasibility and effectiveness of a novel , non-invasive brain stimulation approach that combined an iTBS primer , and bihemispheric stimulation coupled with motor training . We hypothesized that individuals exposed to this novel treatment would make greater functional improvements than individuals undergoing sham stimulation when tested immediately following , 24-h , and 7-days post-training . A total of 26 right-h and ed , healthy young adults were r and omly assigned to either a treatment ( n = 15 ) or control group ( n = 12 ) . iTBS ( 20 trains of 10 pulse triplets each delivered at 80 % active motor threshold ( AMT ) / 50 Hz over 191.84 s ) and bihemispheric tDCS ( 1.0 ma for 20 min ) were used as a primer to , and in conjunction with , 20 min of motor training , respectively . Our primary outcome measure was performance on the Jebsen-Taylor H and Function ( JTHF ) test . Participants tolerated the combined iTBS/bihemispheric stimulation treatment without complaint . While performance gains in the sham and stimulation group were not significant immediately after training , they were nearly significant 24-h post training ( p = 0.055 ) , and were significant at 7-days post training ( p < 0.05 ) . These results suggest that the combined iTBS/bihemispheric stimulation protocol is both feasible and effective . Future research should examine the mechanistic explanation of this approach as well as the potential of using this approach in clinical population Background and Purpose : The purpose of this study was to identify which characteristics of a multidimensional sequence containing motor , spatial , and temporal elements would be most salient for motor sequence learning and whether age might differentially affect this learning . Subjects : Younger ( n=11 , mean age=26.0 years ) , middle-aged ( n=13 , mean age=50.7 years ) , and older ( n=11 , mean age=77.5 years ) adults who were neurologically intact participated in the study . Methods : Participants practice d a sequencing task with repeated motor , spatial , and temporal dimensions for 2 days ; on a separate third day , participants completed retention and interference tests design ed to assess sequence learning and which elements of the sequence were learned . The mean median response time for each block of responses was used to assess motor sequence learning . Results : Younger and middle-aged adults demonstrated sequence-specific motor learning at retention testing via faster response times for repeated sequences than r and om sequences ; both of these groups showed interference for the motor dimension . In contrast , older adults demonstrated nonspecific learning ( ie , similar improvements in response time for both r and om and repeated sequences ) . These findings were shown by a lack of difference between r and om and repeated sequence performance in the older adult group both at retention testing and during interference tests . Conclusion and Discussion : Our data suggest that , when younger and middle-aged adults practice sequences containing multiple dimensions of movement , the motor element is most important for motor learning . The absence of sequence-specific change demonstrated by an older adult group that was healthy suggests an age-related impairment in motor learning that may have profound implication s for rehabilitation Background Definitive evidence that exercise interventions that improve gait also reduce disability is lacking . A task-oriented , motor sequence learning exercise intervention has been shown to reduce the energy cost of walking and improve gait speed , but whether the intervention also improves activity and participation has not been demonstrated . Objective The objective of this study was to compare the impact of a task-oriented , motor sequence learning exercise ( TO ) intervention and the impact of an impairment-oriented , multicomponent exercise ( IO ) intervention on activity and participation outcomes in older adults with mobility limitations . The mediating effects of a change in the energy cost of walking on changes in activity and participation also were determined . Design This study was a single-blind , r and omized controlled trial . Setting The study was conducted in an ambulatory clinical research training center . Participants The study participants were 47 older adults ( mean age=77.2 years , SD=5.5 ) with slow and variable gait . Intervention The intervention was a 12-week , physical therapist – guided program of TO or IO . Measurements Measures of activity ( gait speed over an instrumented walkway ; daily physical activity measured with an accelerometer ; confidence in walking determined with the Gait Efficacy Scale ; and physical function determined with the total , basic lower-extremity , and advanced lower-extremity components of the Late-Life Function and Disability Instrument [ Late-Life FDI ] ) and participation ( disability limitation dimension and instrumental role [ home and community task performance ] domain components of the Late-Life FDI ) were recorded before and after the intervention . The energy cost of walking was determined from the rate of oxygen consumption during self-paced treadmill walking at the physiological steady state st and ardized by walking speed . An adjusted comparison of activity and participation outcomes in the treatment arms was made by use of an analysis of covariance model , with baseline and change in energy cost of walking added to the model to test for mediation . Tests were used to determine the significance of the mediating effects . Results Activity improved in TO but not in IO for confidence in walking ( Gait Efficacy Scale ; mean adjusted difference=9.8 [ SD=3.5 ] ) and physical function ( Late-Life FDI basic lower-extremity component ; mean adjusted difference=3.5 [ SD=1.7 ] ) . Improvements in TO were marginally greater than those in IO for gait speed , physical activity , and total physical function . Participation improved marginally more in TO than in IO for disability limitations and instrumental role . Limitations The older adults were r and omized to the intervention group , but differences in baseline measures had to be accounted for in the analyses . Conclusions A TO intervention that improved gait also led to improvements in some activity and participation outcomes in older adults with mobility limitations Little is known about how children acquire new motor sequences . In particular , it is not clear if the same learning progression observed in adults is also present in childhood nor whether motor skills are acquired in a similar fashion across development . In the present study we used the multi-finger sequencing task ( MFST ) , a variant of the serial reaction time ( SRT ) task , to study motor sequence learning , across two consecutive days , in three cross-sectional sample s of children aged 6 , 8 , and 10 years , and a control sample of adults . In the MFST , participants reproduced 10-element sequences of key presses on an electronic keyboard , using four fingers of the right h and . Each block of practice included 10 intermixed trials of a Repeated ( REP ) sequence and four trials of R and om ( RAN ) sequences . Performance was assessed by examining changes in accuracy , a component of the task that requires the association of the visual stimulus with the motor response , and response synchronization , a component that requires fine-grained sensorimotor integration and timing . Additionally , participants completed Recognition and Recall tests , to assess explicit knowledge of the repeated sequence . Overall , results showed a developmental progression in motor sequence learning within and across days of practice . Interestingly , the two behavioral measures showed different developmental trajectories . For accuracy , differences were greatest for the two youngest groups early in learning , and these groups also showed the greatest rate of improvement . However , by the end of Day 2 , only the 6-year-olds still lagged behind all other groups . For response synchronization , all child groups differed from adults early in learning , but both child and adult groups showed similar rates of improvement across blocks of practice . By the end of Day 2 , 10-year-olds reached adult levels of performance , whereas 6- and 8-year-olds did not . Taken together , the dissociation observed with our two behavioral measures of sequence learning is consistent with the hypothesis that accuracy or finger-stimulus association may rely on cortical pathways that show the greatest maturation between ages 6 and 10 ; whereas motor timing and sensorimotor integration may rely on subcortical pathways that continue to develop into young adulthood . Despite developmental differences across blocks of practice on both behavioral measures , there were no significant group differences for either the Recognition or Recall tests . We suggest that explicit knowledge of the MFST is not directly linked to task performance , thus challenging the implicit – explicit distinction in pediatric SRT studies assessing the developmental invariance model Cardiovascular activity has been shown to be positively associated with gray and white matter volume of , amongst others , frontal and temporal brain regions in older adults . This is particularly true for the hippocampus , a brain structure that plays an important role in learning and memory , and whose decline has been related to the development of Alzheimer ’s disease . In the current study , we were interested in whether not only cardiovascular activity but also other types of physical activity , i.e. , coordination training , were also positively associated with the volume of the hippocampus in older adults . For this purpose we first collected cross-sectional data on “ metabolic fitness  ” ( cardiovascular fitness and muscular strength ) and “ motor fitness ” ( e.g. , balance , movement speed , fine coordination ) . Second , we performed a 12-month r and omized controlled trial . Results revealed that motor fitness but not metabolic fitness was associated with hippocampal volume . After the 12-month intervention period , both , cardiovascular and coordination training led to increases in hippocampal volume . Our findings suggest that a high motor fitness level as well as different types of physical activity were beneficial to diminish age-related hippocampal volume shrinkage or even increase hippocampal volume There is increasing evidence that sleep promotes off-line enhancement of a variety of explicitly learned motor tasks in young adults . However , whether sleep promotes off-line consolidation of implicitly learned motor tasks is still under question . Furthermore , the role of sleep in promoting transfer of learning remains unknown . This study examined the role of sleep in learning and transfer of learning of an implicit continuous motor task . Twenty-three neurologically intact individuals ( mean age 26.4 years ) were r and omly assigned to either a sleep group or a no-sleep group . The sleep group practice d a continuous tracking task in the evening and underwent retention and transfer testing the following morning , while the no-sleep group practice d the tracking task in the morning and underwent retention and transfer testing in the evening . The results show that in both the sleep and no-sleep groups , performance improved off-line without further practice for both the general skill and the sequence-specific skill . The results also indicate that sleep and time promote transfer of learning of both sequence-specific and general skill learning to a spatial and temporal variation of the motor task . These findings demonstrate that sleep does not play a critical role in promoting off-line learning and transfer of learning of an implicit continuous motor task Background Down syndrome ( DS ) has unique physical , motor and cognitive characteristics . Despite cognitive and motor difficulties , there is a possibility of intervention based on the knowledge of motor learning  . However , it is important to study the motor learning process in individuals with DS during a virtual reality task to justify the use of virtual reality to organize intervention programs . The aim of this study was to analyze the motor learning process in individuals with DS during a virtual reality task . Methods A total of 40 individuals participated in this study , 20 of whom had DS ( 24 males and 8 females , mean age of 19 years , ranging between 14 and 30 yrs . ) and 20 typically developing individuals ( TD ) who were matched by age and gender to the individuals with DS . To examine this issue , we used software that uses 3D images and reproduced a coincidence-timing task . Results The results showed that all individuals improved performance in the virtual task , but the individuals with DS that started the task with worse performance showed higher difference from the beginning . Besides that , they were able to retain and transfer the performance with increase of speed of the task . Conclusion Individuals with DS are able to learn movements from virtual tasks , even though the movement time was higher compared to the TD individuals . The results showed that individuals with DS who started with low performance improved coincidence- timing task with virtual objects , but were less accurate than typically developing individuals . Trial registration Clinical Trials.gov Identifier : NCT02719600 [ Purpose ] The acquisition of motor skills are fundamental to human life . There is a lack of research on whether knowledge of performance or knowledge of result as augmented feedback is more effective . The objective of this study was to compare the effectiveness of knowledge of result and knowledge of performance in the learning of a skilled motor activity by healthy young adults . [ Subjects and Methods ] A total of thirty healthy young adult males and females without any neurological or musculoskeletal impairment , between the age of 18–30 years were the subjects of the study . They were r and omly allocated to 2 groups : group 1 was given knowledge of result as feedback , and knowledge of performance was given as feedback to group 2 . Both the groups practice d the task of throwing a soft spongy ball for 6 days per week for 4 weeks , with 40 trials each day . The outcome measure used was the distance of the throw . [ Results ] The results were analyzed using the t-test . The mean distances thrown by both the groups showed highly significant improvements and throwing distance of group 2 showed better improvement than that of group 1 . [ Conclusion ] Both types of augmented feedback were effective at improving skilled motor activity , but the knowledge of performance group showed better improvement than the knowledge of result group Background . One bout of high-intensity cardiovascular exercise performed immediately after practicing a motor skill promotes changes in the neuroplasticity of the motor cortex and facilitates motor learning in nondisabled individuals . Objective . To determine if a bout of exercise performed at high intensity is sufficient to induce neuroplastic changes and improve motor skill retention in patients with chronic stroke . Methods . Twenty-two patients with different levels of motor impairment were recruited . On the first session , the effects of a maximal grade d exercise test on corticospinal and intracortical excitability were assessed from the affected and unaffected primary motor cortex representational area of a h and muscle with transcranial magnetic stimulation . On the second session , participants were r and omly assigned to an exercise or a nonexercise control group . Immediately after practicing a motor task , the exercise group performed 15 minutes of high-intensity interval training while the control group rested . Twenty-four hours after motor practice all participants completed a test of the motor task to assess skill retention . Results . The grade d exercise test reduced interhemispheric imbalances in GABAA-mediated short-interval intracortical inhibition but changes in other markers of excitability were not statistically significant . The group that performed high-intensity interval training showed a better retention of the motor skill . Conclusions . The performance of a maximal grade d exercise test triggers only modest neuroplastic changes in patients with chronic stroke . However , a single bout of high-intensity interval training performed immediately after motor practice improves skill retention , which could potentially accelerate motor recovery in these individuals INTRODUCTION The ultimate goal of physiotherapy in stroke rehabilitation is focused towards physical independence and to restore their functional ability during activities of daily living ( ADLs ) . Motor imagery ( MI ) is an active process during which a specific action is reproduced within working memory without any actual movements . MI training enhances motor learning , neural reorganization and cortical activation in stroke . The efficacy of MI training involving lower extremity mobility tasks need to be assessed . AIM To evaluate the effects of combining motor imagery with physical practice in paretic Lower Extremity Muscles Strength and Gait Performance in Ambulant Stroke subjects . MATERIAL S AND METHODS A R and omized Clinical Trial was conducted in Department of Physical Therapy , Tertiary Care Hospitals , Mangalore , India which includes 40 hemi paretic subjects ( > 3 months post-stroke ) who were ambulant with good imagery ability in both KVIQ-20 ≥ 60 and Time dependent MI screening test were recruited and r and omly allocated into task-oriented training group ( n=20 ) and task-oriented training group plus MI group ( n=20 ) . Subjects in both groups underwent task orientated training for lower extremity 45 - 60 minutes , 4 days per week for 3 weeks . In addition , the experimental group received 30 minutes of audio-based lower extremity mobility tasks for MI practice  . Isometric muscle strength of Hip , Knee and Ankle using a h and -held dynamometer and self-selected 10 m gait speed were assessed before and after 3 weeks of intervention . RESULTS Both the groups had found a significant change for all the outcome measures following 3 weeks of interventions with p < .05 . The experimental group had shown a significant improvement in paretic hip muscles ( both flexors and extensors ) , knee extensors and ankle dorsiflexors and gait speed compare to control group with p < .05 between group analyses . CONCLUSION Additional task specific MI training improves paretic muscle strength and gait performance in ambulant stroke patients We have recently shown that a single bout of acute cardiovascular exercise improves motor skill learning through an optimization of long-term motor memory . Here we exp and this previous finding , to explore potential exercise-related biomarkers and their association with measures of motor memory and skill acquisition .  Thirty-two healthy young male subjects were r and omly allocated into either an exercise or control group . Following either an intense bout of cycling or rest subjects practice d a visuomotor tracking task .  Motor skill acquisition was assessed during practice and retention 1 h , 24 h and 7 days after practice . Plasma levels of brain-derived neurotrophic factor ( BDNF ) , vascular endothelial growth factor ( VEGF ) , insulin-like growth factor ( IGF-1 ) , epinephrine , norepinephrine , dopamine and lactate were analyzed at baseline , immediately after exercise or rest and during motor practice . The exercise group showed significantly better skill retention 24h and 7 days after acquisition . The concentration of all blood compounds increased significantly immediately after exercise and remained significantly elevated for 15 min following exercise except for BDNF and VEGF . Higher concentrations of norepinephrine and lactate immediately after exercise were associated with better acquisition . Higher concentrations of BDNF correlated with better retention 1 h and 7 days after practice . Similarly , higher concentrations of norepinephrine were associated with better retention 7 days after practice whereas lactate correlated with better retention 1h as well as 24 h and 7 days after practice . Thus , improvements in motor skill acquisition and retention induced by acute cardiovascular exercise are associated with increased concentrations of biomarkers involved in memory and learning processes . More mechanistic studies are required to eluci date the specific role of each biomarker in the formation of motor memory
Results concerning the association of chronic physical activity and motor performance are mixed and seem to be influenced by the study design , kind of exercise , motor task , and exercise intensity .
Regarding motor learning , a high physical activity or cardiovascular fitness level seems to boost the initial phase of motor learning ; results differ with respect to motor retention .
Overall , ( motor-coordinative ) intervention studies seem to be more promising than cross-sectional studies
Upper extremity motor performance declines with increasing age .
However , older adults need to maintain , learn new and relearn known motor tasks .
Research with young adults indicated that regular and acute physical activity might facilitate motor performance and motor learning processes .
Therefore , this review aim ed to examine the association between chronic physical activity and acute bouts of exercise on motor performance and motor learning in upper extremity motor tasks in older adults .