Effects of contextual interference and age on acquisition, retention, and transfer of motor skill

Smartphone-Based Sit-to-Stand Analysis for Mobility Assessment in Middle Age

Background and Objectives

Mobility can decline in middle age and growing evidence highlights the importance of assessing mobility at this stage of life. Smartphone-based accelerometry during sit-to-stand has been shown to identify mobility impairments, but its utility in detecting subtle mobility deterioration in middle age has not been tested. This study aimed to examine whether smartphone-based accelerometry data measured during sit-to-stand tests performed on a regular chair and a cushioned sofa could be useful for detecting subtle changes in mobility in middle age.

Research Design and Methods

Twenty-three young (25.0 ± 2.5 years), 25 middle-aged (52.0 ± 5.2 years), and 17 older adults (70.0 ± 4.1 years) performed the 5-times sit-to-stand test on both a standard chair and a sofa. A smartphone attached to the participants' lower back was used to measure lower-limb muscle power, maximal vertical velocity (MVV) during rising, the duration of the total task and the subphase of transition from sitting to standing (SiToSt), and repetition variability using the dynamic time warping method.

Results

Middle-aged adults had reduced lower-limb muscle power compared to young adults (5.25 ± 1.08 vs 6.19 ± 1.38 W/kg, p = .034), being more pronounced on the sofa (6.23 ± 1.61 vs 8.08 ± 2.17 W/kg, p = .004). Differences between middle-aged and young adults in terms of MVV (p = .011) and SiToSt duration (p = .038) were only detected on the sofa, and the middle-aged adults showed less variability compared to the older adults on the chair (p = .018). There was no difference in total task duration between the middle-aged group and the young or older adults in either condition.

Discussion and Implications

Most common tests are limited in their ability to detect early mobility deterioration in midlife due to a ceiling effect. Our results, which show the potential of smartphone-based sit-to-stand assessment in detecting subtle mobility decline in midlife, could serve as a screening tool for this purpose.

Prefrontal Cortex Activation During Motor Sequence Learning Under Interleaved and Repetitive Practice: A Two-Channel Near-Infrared Spectroscopy Study

Training under high interference conditions through interleaved practice (IP) results in performance suppression during training but enhances long-term performance relative to repetitive practice (RP) involving low interference. Previous neuroimaging work addressing this contextual interference effect of motor learning has relied heavily on the blood-oxygen-level-dependent (BOLD) response using functional magnetic resonance imaging (fMRI) methodology resulting in mixed reports of prefrontal cortex (PFC) recruitment under IP and RP conditions. We sought to clarify these equivocal findings by imaging bilateral PFC recruitment using functional near-infrared spectroscopy (fNIRS) while discrete key pressing sequences were trained under IP and RP schedules and subsequently tested following a 24-h delay. An advantage of fNIRS over the fMRI BOLD response is that the former measures oxygenated and deoxygenated hemoglobin changes independently allowing for assessment of cortical hemodynamics even when there is neurovascular decoupling. Despite slower sequence performance durations under IP, bilateral PFC oxygenated and deoxygenated hemoglobin values did not differ between practice conditions. During test, however, slower performance from those previously trained under RP coincided with hemispheric asymmetry in PFC recruitment. Specifically, following RP, test deoxygenated hemoglobin values were significantly lower in the right PFC. The present findings contrast with previous behavioral demonstrations of increased cognitive demand under IP to illustrate a more complex involvement of the PFC in the contextual interference effect. IP and RP incur similar levels of bilateral PFC recruitment, but the processes underlying the recruitment are dissimilar. PFC recruitment during IP supports action reconstruction and memory elaboration while RP relies on PFC recruitment to maintain task variation information in working memory from trial to trial. While PFC recruitment under RP serves to enhance immediate performance, it does not support long-term performance.

The role of the practice order: A systematic review about contextual interference in children

Aim

We aimed to identify and evaluate the quality and evidence of the motor learning literature about intervention studies regarding the contextual interference (CI) effect (blocked vs. random practice order) in children with brain lesions and typically developing (TD) children.

Method

Eight databases (Cinahl, Cochrane, Embase, PubMed, Pedro, PsycINFO, Scopus and Web of Knowledge) were searched systematically with predefined search terms. Controlled studies examining the CI effect in children (with brain lesions or TD) were included. Evidence level, conduct quality, and risk of bias were evaluated by two authors independently. A best evidence synthesis was performed.

Results

Twenty-five papers evaluating TD children were included. One of these studies also assessed children with cerebral palsy. Evidence levels were I, II, or III. Conduct quality was low and the risk of bias high, due to methodological issues in the study designs or poor description thereof. Best evidence synthesis showed mainly no or conflicting evidence. Single tasks showed limited to moderate evidence supporting the CI effect in TD children.

Conclusion

There is a severe limitation of good-quality evidence about the CI effect in children who practice different tasks in one session, especially in children with brain lesions.

Learning better by repetition or variation? Is transfer at odds with task specific training?

Objective

Transfer of motor skills is the ultimate goal of motor training in rehabilitation practice. In children with Developmental Coordination Disorder (DCD), very little is known about how skills are transferred from training situations to real life contexts. In this study we examined the influence of two types of practice on transfer of motor skills acquired in a virtual reality (VR) environment.

Method

One hundred and eleven children with DCD and their typically developing (TD) peers, aged 6–10 years (M = 8.0 SD = 1.0) were randomly assigned to either variable (n = 56) or repetitive practice (n = 55). Participants in the repetitive practice played the same exergame (ski slalom) twice weekly for 20 minutes, over a period of 5 weeks, while those in the variable group played 10 different games. Motor skills such as balance tasks (hopping), running and agility tasks, ball skills and functional activities were evaluated before and after 5 weeks of training.

Results

ANOVA repeated measures indicated that both DCD and TD children demonstrated transfer effects to real life skills with identical and non-identical elements at exactly the same rate, irrespective of the type of practice they were assigned to.

Conclusion

Based on these findings, we conclude that motor skills acquired in the VR environment, transfers to real world contexts in similar proportions for both TD and DCD children. The type of practice adopted does not seem to influence children’s ability to transfer skills acquired in an exergame to life situations but the number of identical elements does.

Contextual Interference in Learning Precision Skills

This research studied the effect of different organisations of practice (blocked and random) on the learning of three different types of throwing. 35 male students practiced three precise throws for 3 wk. Initially the subjects were separated into two groups who trained under different conditions of practice (blocked and random). All subjects improved significantly from initial performance, with both blocked practice and random practice. At the end of acquisition no differences were found between the groups. No significant differences were found on retention tests carried out 48 hr., 4 wk., and 8 wk. after the training period.

Contextual Interference: A Meta-Analytic Study

A meta-analysis of the contextual interference effect produced 139 estimates of effect sizes from 61 studies. The average overall effect size was .38. The effect size for basic research (.57) was significantly different from applied research (.19). Significant differences were also obtained between the effect sizes for adults (.50) and those for younger learners (.10). Power for retention and transfer scores was not significantly different. The overall mean power of the studies reviewed was .43.

The effect of a short bout of practice on reaching behavior in late preterm infants at the onset of reaching: a randomized controlled trial

The purpose of this study was to examine the effects of a short bout of practice on reaching behavior in late preterm infants at the onset of goal-directed reaching. The study was designed as a blind, three-arm parallel-group, randomized controlled, clinical trial. Thirty-six late preterm infants were recruited from a maternity hospital and allocated according to computer generated randomization into groups that received reaching practice based on either a blocked schedule, a serial schedule, or no practice. Practice consisted of a 4 min session of induced reaching using a toy in three activities guided by a physical therapist. The activities were elicited in separate blocks for the blocked practice group and in a pre-established order for the serial practice group. The control group stayed in the physical therapist's lap but was not stimulated to reach. The infants were assessed 3.3±1.4 days after the onset of goal-directed reaching in three tests: pre-test (immediately before practice), post-test (immediately after practice), and retention test (24 h after post-test). During assessments, the infants were seated in a baby chair and a toy was presented at his/her midline within reaching distance for 2 min. Changes in the number of reaches, proportions of uni/bimanual reaches and kinematic parameters of reaching were main outcome measures. From pre- to post-test, the amount of reaches and bimanual reaches increased in the serial practice group, but the increase was not maintained in the retention test. Kinematic parameters were not affected by practice. Changes in the reaching behavior of late preterm infants can be triggered after the first few minutes of toy-oriented experience based on a serial practice schedule. These changes are not consolidated one day later.

Documenting the content of physical therapy for children with acquired brain injury: development and validation of the motor learning strategy rating instrument

BACKGROUND

A goal of physical therapy interventions for children and youth with acquired brain injury (ABI) is the learning and relearning of motor skills. Therapists can apply theoretically derived and evidence-based motor learning strategies (MLSs) to structure the presentation of a task and organize the environment in ways that may promote effective, transfer-oriented practice. However, little is known about how MLSs are used in physical therapy interventions for children with ABI.

OBJECTIVE

The purpose of this study was to develop and validate an observer-rated Motor Learning Strategy Rating Instrument (MLSRI) quantifying the application of MLSs in physical therapy interventions for children with ABI.

DESIGN

A multi-stage, iterative, item generation and reduction approach was used.

METHODS

An initial list of MLS items was generated through literature review. Seven experts participated in face validation to confirm item comprehensiveness. In a content validation process, 12 physical therapists with pediatric ABI experience responded to a questionnaire evaluating feasibility and importance of items. Six physical therapy sessions with clients with ABI were videotaped at a children's rehabilitation center. The 12 physical therapists participated in a session where they: (1) rated session videos to test the MLSRI and (2) provided verbal feedback.

RESULTS

Revisions were made sequentially to the MLSRI based on these processes.

LIMITATIONS

The MLSRI was scored during videotape observation rather than being given a live rating, which may be onerous in certain settings and may influence therapist or child behavior.

CONCLUSIONS

Further reliability investigations will determine whether the 33-item MLSRI is of help in documenting strategy use during intervention, as an evaluation tool in research, and as a knowledge transfer resource in clinical practice.

Simultaneous Treatment Effects in Learning Four Tennis Shots in Contextual Interference Conditions

This study investigated simultaneous treatments in contextual interference (blocked and random practice) and their effect on the process of learning four tennis shots. 8 tennis players participated in the research, which was carried out in two phases. The first phase involved a 3-wk. period of 12 sessions with 192 practice tennis shots per session for each tennis player. The second phase comprised 4 retention tests carried out at 48 hr. and 2, 4, and 6 weeks following the learning phase. This phase consisted of evaluating the retention of the skills that had been practiced during the learning phase. The results indicated an improvement in the quality of shots for both practice conditions during the learning phase. Differences in retention appeared relative to differences in the type of practice conditions (random or blocked) in which the skill was learned and also depended on the type of shot and the time that had elapsed since the learning period.

A reflection on motor learning theory in pediatric occupational therapy practice

BACKGROUND

Theory provides a guide to clinical practice. To date, the most prevalent theories in pediatric occupational therapy practice are sensory integration and neurodevelopmental treatment.

PURPOSE

The purpose of this paper is to present a brief overview and reflection on motor learning theories as well as a summary of motor learning principles that can be used in pediatric practice.

KEY ISSUES

Over the past two decades, motor learning theory has been applied in adult occupational therapy practice, but it has been slow to gain popularity in pediatrics.

IMPLICATIONS

Although therapists may be tacitly applying motor learning principles in practice, conscious and deliberate application of these principles to a variety of pediatric populations is required to determine if motor learning theory provides a viable and effective contribution to evidence-based, occupational therapy pediatric practice. Further research comparing motor learning interventions to other dominant interventions in pediatric occupational therapy is warranted.

Effects of different practice conditions on acquisition, retention, and transfer of soccer skills by 9-year-old schoolchildren

This study was designed to examine effects of three practice models, blocked, variable, and combined, on the acquisition, retention, and transfer of new motor skills. 67 subjects (M age = 9.5 yr., SD = .3) from the fourth year of primary school (31 boys and 26 girls) were assigned at random to three different practice groups (Blocked = 22, Variable = 23, Combined = 22) to study acquisition of two skills, dribbling a soccer ball and kicking a soccer ball at a stationary target using the dominant foot. All participants received a pretest and posttest, a transfer test, and a retention test 2 wk. later. Analysis showed significant improvement after practice of kicking skills by the three groups but not in the dribbling skills, for which only the combined practice group showed any notable improvement. At the end of acquisition, the combined practice group had significantly better performance on the dribbling task than the other two groups. However, the only differences noted in performance of kicking the ball with the dominant foot were by combined practice and blocked groups.

Developmental coordination disorder in children with attention-deficit-hyperactivity disorder and physical therapy intervention

Although physical therapy (PT) is effective in improving motor function in children with developmental coordination disorder (DCD), insufficient data are available on the impact of this intervention in children with combined attention-deficit-hyperactivity disorder (ADHD) and DCD. This prospective study aimed to establish the prevalence of DCD among a cohort of patients with ADHD, characterize the motor impairment, identify additional comorbidities, and determine the role of PT intervention on these patients. DCD was detected in 55.2% of 96 consecutive children with ADHD (81 males, 15 females), mostly among patients with the inattentive type (64.3% compared with 11% of those with the hyperactive/impulsive type, p<0.05). Mean age was 8 years 4 months (SD 2 y). Individuals with both ADHD and DCD more often had specific learning disabilities (p=0.05) and expressive language deficits (p=0.03) than children with ADHD only. Twenty-eight patients with ADHD and DCD randomly received either intensive group PT (group A, mean age 9 y 3 mo, SD 2 y 3 mo) or no intervention (group B, mean age 9 y 3 mo, SD 2 y 2 mo). PT significantly improved motor performance (assessed by the Movement Assessment Battery for Children; p=0.001). In conclusion, DCD is common in children with ADHD, particularly of the inattentive type. Patients with both ADHD and DCD are more likely to exhibit specific learning disabilities and phonological (pronunciation) deficits. Intensive PT intervention has a marked impact on the motor performance of these children.

Contextual interference effects in learning volleyball skills

The aim of this study was to examine the contextual interference effect on learning three volleyball skills. Participants were 26 novice female volleyball players (M age= 12.4 yr., SD= 1.2). They were assigned into two groups, Low Interference (n = 13) and High Interference (n = 13). Two practice schedules were used: blocked (Low Interference) and random (High Interference). The training period lasted for 10 weeks and included 2 training sessions of 75 min. each per week. The pretest was performed before the first training session, the posttest was performed after the completion of the last training period, and the retention test was performed two weeks after the posttest. A 2 (Groups) x 3 (Measurement Periods) analysis of variance with repeated measures indicated significant improvement in performance between pre- and posttests for both High Interference and Low Interference groups for the three skills included in this study. There was no significant main effect of group or interaction effect of group and measure. These findings suggest that either blocked or random practice could be effectively used in learning of volleyball skills by unskilled children.

Contextual interference: single task versus multi-task learning

This experiment examined contextual interference in producing a bimanual coordination pattern of 90 degree angle relative phase. Acquisition, retention, and transfer performance were compared in a single-task control group and groups that performed 2 tasks in either a blocked or random presentation. Surprisingly, acquisition data revealed that both the random and control groups outperformed the blocked group. Retention data showed a typical CI effect for performance variability, with the random group outperforming the blocked group. Neither the random nor blocked groups outperformed the control group, suggesting interference of a second task may be as beneficial to learning as extra practice on the initial task. No group effects were found during transfer performance. Results suggest that random practice is beneficial for learning only one task.

High Levels of Contextual Interference Enhance Handwriting Skill Acquisition

The authors conducted 3 experiments to examine whether introducing high levels of contextual interference is useful in handwriting skill acquisition. For all experiments, elementary school students (Ns = 44, 50, and 78, respectively) were randomly assigned to 1 of 2 practice schedules-blocked or random practice-in the acquisition phase. In the blocked condition, each of 3 letters (h, a, and y) or (in Experiment 1) symbols was handwritten 24 times consecutively. In the random condition, each letter (or symbol) was practiced 24 times, but in an intermixed, unsystematic sequence. Overall, the results showed that the random practice schedule leads to enhanced retention and transfer performance of handwriting skill acquisition.

Practice schedule and acquisition, retention, and transfer of a throwing task in 6-yr.-old children

Earlier studies have raised questions about the usefulness of variable and random practice in learning motor tasks so this study was designed to investigate the effects of contextual interference in young children, and specifically to evaluate the effectiveness of variable or random practice structure in 6-yr.-old boys and girls. Participants on a variable practice schedule showed better performances than those on a blocked schedule. The differences between the two groups were significant in the acquisition, retention, and transfer phases. These results support the hypothesis that contextual interference enhances skill learning. Because the study involved groups of young children in the setting of their normally scheduled physical education class, the practical applications of the results are evident.

Effects of cognitive processes and task complexity on acquisition, retention, and transfer of motor skills

This experiment was designed to investigate the effect of cognitive problem-solving operations (termed contextual interference) and complexity of tasks on the acquisition retention and transfer of motor skills. Ninety-six children, ages 7.5-9.5 practiced the task of throwing beanbags under either low contextual interference (blocked practice), high contextual interference (random practice) or medium contextual interference (combined practice). Half of the participants acquired a complex task and the other half a simple task. All participants performed 30 acquisition trials, 9 retention trials and 4 transfer trials. Results indicated that participants who practiced in the blocked practice group did not differ in their performance whether they acquired complex or simple tasks. On the other hand, participants from the random and combined practice groups who acquired simple tasks performed better than those who acquired complex tasks. These findings support the hypothesis that there is a limit to the interference during practice that will benefit retention and transfer, thus creating the contextual interference effect. It seems that the complex-task condition combined with random or combined practice schedule increased the difficulty of acquisition, possibly impeding the cognitive processing during acquisition, thus impairing the learning process.

Effects of Cognitive Processes and Task Complexity on Acquisition, Retention, and Transfer of Motor Skills

This experiment was designed to investigate the effect of cognitive problem-solving operations (termed contextual interference) and complexity of tasks on the acquisition retention and transfer of motor skills. Ninety-six children, ages 7.5-9.5 practised the task of throwing beanbags under either low contextual interference (blocked practice), high contextual interference (random practice) or medium contextual interference (combined practice). Half of the participants acquired a complex task and the other half a simple task. All participants performed 30 acquisition trials, 9 retention trials and 4 transfer trials. Results indicated that participants who practised in the blocked practice group did not differ in their performance whether they acquired complex or simple tasks. On the other hand, participants from the random and combined practice groups who acquired simple tasks performed better than those who acquired complex tasks. These findings support the hypothesis that there is a limit to the interference during practice that will benefit retention and transfer, thus creating the contextual interference effect. It seems that the complex-task condition combined with random or combined practice schedule increased the difficulty of acquisition, possibly impeding the cognitive processing during acquisition, thus impairing the learning process.

Variability effects on retention of a motor skill in elementary school children

Variability effects on learning, retention, and transfer of motor skills have been a main issue for scientists involved in laboratory and field research. Variable practice is intended as parameter variations of a generalized motor program as well as rehearsal of different motor programs. Although the benefits deriving from variable practice on motor skill retention appear quite robust in laboratory settings, field investigations have produced mixed results. Hence, the aim of this study was to examine the effects of different variable schedules on the retention of a complex min tor skill in a physical education setting. 61 elementary school children were assigned Blocked/Nonvariable, Blocked/Variable, Serial/Nonvariable, or Serial/Variable schedules, and practiced two tasks (throwing and hurdle running) and a complex skill (jumping) across 14 lessons. Improved performance in the complex skill was found after practice, with the Serial/Nonvariable group outperforming all other groups. Therefore. the rehearsal of different motor programs was beneficial for jumping skill retention, whereas parameter variation was not.