Constrained Action Hypothesis Research Articles

Advancing mental imagery research from an interdisciplinary sport science perspective: a commentary on Frank et al. (2023).

Frank et al.'s (2023) perceptual-cognitive scaffold meaningfully extends the cognitive action architecture approach and we support this interdisciplinary advancement. However, there are theoretical and applied aspects that could be further developed within this research to maximise practical impact across domains such as sport. In particular, there is a need to consider how these mechanisms (1) might critically inform or relate to other prominent theories within sport (e.g., constrained action hypothesis and ecological approaches) and, (2) reflect the real-world challenges experienced by athletes. With these ideas in mind, this commentary aims to stimulate discussion and enhance the translational application of Frank et al.'s research.

Attentional focus effects on joint covariation in a reaching task

Adopting an external focus of attention (EF) has been found beneficial over internal focus (IF) for performing motor skills. Previous studies primarily examined focus of attention (FOA) effects on performance outcomes (such as error and accuracy), with relatively less emphasis on movement coordination. Given that human movements are kinematically and kinetically abundant (Gefland & Latash, 1998), FOA instructions may change how motor abundance is utilized by the CNS. This study applied the uncontrolled manifold analysis (UCM) to address this question in a reaching task. Healthy young adults (N = 38; 22 ± 1 yr; 7 men, 31 women) performed planar reaching movements to a target using either the dominant or nondominant arm under two different FOA instructions: EF and IF. Reaching was performed without online visual feedback and at a preferred pace. Joint angles of the clavicle-scapula, shoulder, elbow, and wrist were recorded, and their covariation for controlling dowel endpoint position was analyzed via UCM. As expected, IF led to a higher mean radial error than EF, driven by increases in aiming bias and variability. Consistent with this result, the UCM analysis showed that IF led to higher goal-relevant variance among the joints (VORT) compared to EF starting from the first 20% of the reach to the end. However, the goal-irrelevant variance (VUCM)—index of joint variance that does not affect the end-effector position—did not show FOA effects. The index of stability of joint coordination with respect to endpoint position (ΔV) was also not different between the EF and IF. Consistent with the constrained action hypothesis, these results provide evidence that IF disrupted goal-relevant joint covariation starting in the early phases of the reach without affecting goal-irrelevant coordination.

Focus of Attention in Coach Instructions for Technique Training in Sports: A Scrutinized Review of Review Studies

Literature reports superior performance when focusing one's attention during a movement on environmental effects of that movement (external focus, EF) compared to focusing on the moving body (internal focus, IF). Nevertheless, IF instructions still play an important role in the daily practice of coaches, trainers, and therapists. The current review compiles evidence for focus-of-attention concepts on movement form corrections and technique training. Reviews on the topic and selected additional papers addressing the effect of attentional focus on movement form or on kinetic, kinematic or muscle activity data were included. Both EF and IF instructions affect movement form. The reviews revealed that IF instructions seem to be better applicable to direct movement form changes than EF instructions. In contrast, EF instructions better facilitate optimization within the whole-body coordination, often resulting in better performance outcomes not directly linked to movement pattern changes. Several studies discuss focus-of-attention effects in the context of the optimal feedback control theory expanding on the constrained action hypothesis. In summary, EF and IF instructions both affect form and performance of movements, however, their relative efficacy is situation dependent. The often-purported superiority of EF over IF instructions cannot be generalized to all application contexts.

A meta-analysis on immediate effects of attentional focus on motor tasks performance

ABSTRACT Directing the attentional focus towards intended movement effects could enhance individual performance. This meta-analysis examines the immediate effects of an instructed external (proximal/distal) and internal attentional focus on an experimental group and a control group on their performance. A systematic review was done following the PRISMA guidelines. A total of 3833 reports were scanned. Of these, 83 were included in the systematic review, and 61 studies were included into the meta-analysis. The meta-analysis was additionally split into the original categories, which included the instructions as mentioned in the paper, and the adapted classifications, for which the instructions were reclassified based on the definition by [Wulf, G. (2013). Attentional focus and motor learning: A review of 15 years. International Review of sport and Exercise psychology, 6(1), 77–104. doii:10.1080/1750984X.2012.723728 and McNevin, N. H., Shea, C. H., & Wulf, G. (2003). Increasing the distance of an external focus of attention enhances learning. Psychological Research, 67(1), 22–29. doii:10.1007/s00426-002-0093-6]. In line with the constrained-action hypothesis, an external attentional focus instruction enhanced the immediate performance compared to an internal attentional focus instruction (SMDadapted = 0.24) and the control group (SMDadapted SMD = 0.31). Also, consistent with the constrained-action hypothesis, distal external attentional focus instructions showed performance-enhancing effects compared to proximal external attentional focus instructions (SMDadapted = 0.23). However, most comparisons showed moderate to substantial heterogeneity and wide prediction intervals. Therefore, the results cannot be generalized for all tasks and skill levels.

Instructions for External Focus of Attention Improved Taekwondo Kicking Performance Only Among Less Skilled Youth.

External focus of attention (EFA) studies among children have yielded more equivocal results than have those among adults. Some investigators have found an internal focus of attention (IFA) advantage in children and have explained their results by children’s generally lower skill levels, compared to adults. According to the constrained action hypothesis, children’s lower skill levels are not yet associated with over-learned automatic movement patterns, so their motor performance is not disrupted by IFA instructions. In this study, our objective was to examine a possible interaction effect between children’s skill levels and their exposure to either IFA or EFA instructions on motor performance. Our participants were 40 10–15-year-old taekwondo competitors of higher and lower skill levels (based on both the participant’s experience and their test performance) who engaged in a taekwondo kicking movement before and after either IFA or EFA instructions. We found improved kicking performance with EFA versus IFA instructions only among less versus more skilled participants.

Effects of Attentional Focus on Motor Performance and Physiology in a Slow-Motion Violin Bow-Control Task: Evidence for the Constrained Action Hypothesis in Bowed String Technique.

The constrained action hypothesis states that focusing attention on action outcomes rather than body movement improves motor performance. Dexterity of motor control is key to successful music performance, making this a highly relevant topic to music education. We investigated effects of focus of attention (FOA) on motor skill performance and EMG muscle activity in a violin bowing task among experienced and novice upper strings players. Following a pedagogically informed exercise, participants attempted to produce single oscillations of the string at a time under three FOA: internal (on arm movement), external (on sound produced), and somatic (on string resistance). Experienced players’ number of bow slips was significantly reduced under somatic focus relative to internal, although number of successful oscillations was not affected. Triceps electromyographic activity was also significantly lower in somatic compared to internal foci for both expertise groups, consistent with physiological understandings of FOA effects. Participants’ reported thoughts during the experiment provided insight into whether aspects of constrained action may be evident in performers’ conscious thinking. These results provide novel support for the constrained action hypothesis in violin bow control, suggesting a somatic FOA as a promising performance-enhancing strategy for bowed string technique.

The Effects of Internal Attention on Knee Biomechanics in Volleyball Spike Jump through Augmented Video Feedback.

Poor knee biomechanics in a volleyball spike jump generally result in a higher knee injury risk, which can be altered by an internal focus of attention (FOA). The constrained action hypothesis (CAH) purports that the FOA inhibits sports performance whereas no ecologically valid evidence has been found in previous studies. The purpose of this research is to explore the effect of video feedback on knee biomechanics in a volleyball spike jump including landing and take-off phases. The video feedback was performed in a natural way. Fourteen volleyball male players were recruited in this study. A paired t-test was used to detect the effect of the feedback; meanwhile, statistical parameter mapping (SPM) statistics were used for the continuum differences during movement. After biofeedback, the initial contact flexion angle of the knee (t = 2.179, p = 0.049), the maximal flexion angle of the knee (t = 3.242, p = 0.006) and the maximal internal rotation angular velocity of the knee (t = 5.209, p = 0.003) increased significantly; the maximal extension moment of the knee (t = 3.962, p < 0.001) and the maximal flexion moment of the knee (t = −3.711, p = 0.002) significantly decreased; the maximal abduction moment significantly decreased (t = 3.069, p = 0.037) but the maximal internal rotation moment significantly increased (t = 2.813, p = 0.018); the first peak of the vertical ground reaction force (vGRF) (t = 7.618, p < 0.001) and the average loading rate to the first peak (t = 4.205, p = 0.004) significantly decreased; the other peaks of the vGRF were not found to have differences; a larger knee flexion was found during the phase from 31.17 to 73.19% (t = 2.611, p = 0.012); a larger adduction angular velocity was found during the phase from 49.07 to 62.46% (t = 3.148, p = 0.004); a smaller external rotational angular velocity was found during the phase from 45.85 to 49.96% (t = 5.011 p = 0.017); there was an increased flexion moment of the knee during the phase from 19.72 to 21.38% (t = 0.029, p = 0.029) and an external moment of the knee during the phase from 85.55 to 95.06% (t = 4.214, p < 0.001); the vGRF significantly decreased during the phase from 3.13 to 5.94% (t = 4.096, p = 0.014) and 19.83–21.97% (t = 4.096, p = 0.024) but significantly increased in the phase of 91.43–100% (t = 4.096, p < 0.001). The impulse of the vGRF and knee power were not found to be different compared with before biofeedback. Therefore, our study suggests video feedback in a natural practice has the potential to improve knee movement whilst not altering the performance in a volleyball spike jump. This indicates that the CAH theory is possibly not suitable in a real competition. Due to the complexity of human movements and the limitations of this study, muscle activities must be considered in the future.

Focus of Attention: a Challenge on Predicting Constrained Action Hypothesis

Focus of Attention: a Challenge on Predicting Constrained Action Hypothesis

Internal focus instruction increases psychological stress with conscious motor processing and deteriorates motor performance in dart throwing.

Internal focus attention strategies have been found to diminish motor performance. This study attempted to elucidate this finding using the constrained action hypothesis and the theory of reinvestment through exploring their underlying mechanisms. Sixty-one young participants completed a self-paced "dart throwing" motor task to examine the effects of internal focus instruction, compared with no focus instruction, on conscious motor processing (reinvestment), psychological stress, and motor performance. Participants threw darts with standardized internal focus and no focus instructions given before each trial block of dart throwing. Motor performance was indicated by the throw accuracy and throw time. Stress was measured using a galvanic skin response probe. An insight into real-time conscious motor processing (reinvestment) was provided by the electroencephalography coherence between T3 and Fz locations on the scalp. Results indicated that internal focus instruction could cause participants to have lower throw accuracy (p = 0.008), longer throw time (p = 0.001), higher stress (p = 0.001) and higher real-time conscious motor processing (reinvestment) (p = 0.001) than no focus instruction. The significant results imply that internal focus instruction should be avoided in the self-paced motor task learning due to its detrimental effects.

Focus of attention and online demonstration effects on temporal error and muscle activation

Abstract The purpose of the present study was to examine whether there would be performance differences between external and internal focus of attention conditions and an online demonstration condition, and if these differences would be observed at a neuromuscular level through EMG analysis, in addition to traditional outcome measures. We hypothesized that under the demonstration condition participants would perform better than under external and internal focus conditions. We also hypothesized that demonstration condition would show smaller EMG activity than external and internal focus conditions. Furthermore, we hope to replicate the benefits of external focus in relation to internal focus, both in outcome and product measures. Six male participants performed a bilateral leg extension under internal focus of attention, external focus of attention and online demonstration conditions. Muscular contractions goal times were set for concentric muscle action (4 seconds) and eccentric muscle action (2 seconds). An electrogoniometer was used to record muscular activation (production measures), and temporal error was used to observe performance (outcome measures). Results showed that online demonstration condition obtained better performance than external focus condition and a reduced muscular activation. However, differences between internal focus and the other experimental conditions were not found. These findings advance in the understanding mechanisms underpining the focus of attention, such as proposed by Constrained Action Hypothesis.

Does Attention Modify Contributions to Heaviness Perception?

ABSTRACT Purpose: The current study investigated the effect of attention on heaviness perception and its physiological and kinematic contributions. Method: Participants lifted objects that varied in mass and volume while their muscle activity and movement were recorded. Participants were instructed to pay attention to their arm (internal) or the object (external). Results: While heaviness perception did not change as a function of attention, whether muscle activity and movement combined for perception differed across attention conditions. Specifically, muscle activity and movement combined to significantly predict heaviness perception in the external condition, but not the internal condition. Additionally, movement was more salient for perception in both conditions compared to previous research investigating the contribution of muscle activity and movement to heaviness perception. Conclusion: It is suggested that these results support the constrained action hypothesis, which suggests that adopting an external focus of attention benefits motor task performance and learning, and should be further explored in the context of a theory of haptic perception that suggests that the medium for haptic perception is the multifractal tensegrity structure of the body.

An internal focus of attention is optimal when congruent with afferent proprioceptive task information

Whilst benefits of an external focus are shown to govern several characteristics of skill execution, specificity theory indicates that sources of afferent information most useful to performance execution are typically prioritised during processing. ObjectivesWe investigated whether an internal focus facilitates performance when pertinent afferent information is proprioceptive in nature and congruent with attentional focus. We also considered whether the mechanisms behind attentional focus differences are attributable to planning processes or online motor control. DesignExperiments 1 and 2 adopted a randomised design, whilst experiment 3 used a repeated measures approach. MethodIn Experiment 1 we investigated movement variability as a measure of planning and error correction under external and internal focus conditions in an aiming task. Experiment 2 removed visual information to increase pertinence of proprioceptive feedback for movement execution and Experiment 3 adopted a leg-extension task, where proprioceptive salience was enhanced using an ankle weight. We hypothesised that this would increase congruency between internal focus instructions and movement production. ResultsExperiments 1 and 2 revealed reduced amplitude errors under an internal focus whilst Experiment 3 showed similar findings with the addition of lower EMG activity when adopting an internal focus. Movement variability findings were indicative of enhanced planning. ConclusionsWhen pertinence of proprioceptive information was amplified, benefits of an internal focus were more pronounced and performance was higher. Participants were better able to focus on movement characteristics to process proprioceptive feedback: something not afforded under an external focus. This raises doubts regarding the rigidity of the constrained action hypothesis.

Impact of attentional focus on motor performance within the context of “early” limb regulation and “late” target control

Directing attention to the effect of one's movement (external focus) has been shown to aid performance compared to directing attention to the movement itself (internal focus). This finding has been predominantly explained by an external focus promoting action planning and automatic movement control, while an internal focus acts to constrain movement (constrained action hypothesis [CAH]). In a separate line of research, the multiple control process model states that early movement phases involve anticipated and feedforward processes, while late movement phases explicitly incorporate external afferent information. We hypothesized that enhanced planning and automatic movement control would manifest from an external/distal focus compared to internal/proximal focus. The present study had participants execute fast and accurate movements to a single target using a digitizing graphics tablet that translated movements to a screen. Participants were instructed to focus on the end target location (external-distal), movement of the cursor (external-proximal), and movement of the limb (internal-proximal). It was found that the external-distal focus generated a shorter time to initiate and execute movements (indicating enhanced movement planning) compared to the external- and internal-proximal conditions. In addition, only the external proximal focus revealed a reduction in spatial variability between peak velocity and movement end (indicating greater online control). These findings indicate that advances in action planning and online control occur when adopting an external-distal focus. However, there were some benefits to online control when adopting an external-proximal focus. We propose that an external-distal focus promotes action-effect principles, where there is a greater contribution of anticipatory feedforward processes that limit the need for late online control.

Lets go surfing now, everybody’s learning how; attentional strategies on expert and novice surfing performance under both practice and competition conditions

Research suggests an external focus of attention (EFOA) promotes effective performance and learning compared to an internal focus of attention (IFOA), with explanations proposed by the constrained action hypothesis (CAH) and OPTIMAL theory of motor learning. Specifically, it is proposed that adopting an EFOA prevents the constraining of normally automatic control processes and subsequent performance decrements (typically observed when individuals adopt an IFOA) by simultaneously reducing self-focus strategies and enhancing goal-action coupling. The present study attempted to fill this research lacuna by examining the CAH and OPTIMAL theory in a complex, ecologically valid, motor task under both low and high-pressured conditions. In two separate experiments, novice (n = 23) and advanced (n = 21) surfers completed a surfing task in an artificial Wavegarden under either EFOA or IFOA instructions. Experimental phases included a pre-test, acquisition and competition transfer. Results revealed that advanced and novice surfing performance benefited from adopting an EFOA in both normal and competitive situations. These findings are discussed in terms of the theoretical implications for the CAH and OPTIMAL theory, in addition to the anxiety literature. Reference to applied implications when instructing and performing within ecologically valid surfing settings are also presented.

Effects of attentional focus on movement coordination complexity

Attentional focus affects performance and learning of motor tasks. An external attentional focus (on the effects of movement) can lead to more efficient and effective movements compared to an internal focus (on body movement itself). According to the “constrained action hypothesis”, an external focus facilitates fast and reflexive movement control while an internal focus leads to disruption of automatic coordination processes. Such disruption should be apparent in the complexity of movement. In this study, multiscale entropy measures were used to investigate if the external focus is related to superior coordination complexity compared to internal focus. Twenty participants were divided in two groups that balanced over an unstable platform in fourteen trials over two days, either with internal or external focus of attention instructions, followed by seven retention trials on the third day. Multiscale entropy measures were used to quantify complexity of motions of the platform, the participant, and the composite of participant and platform motions. Results were contrary to expectations. For the external focus group, despite better overall performance, multiscale entropy values of participant and composite motions were lower in some scales compared to the internal focus group, especially in the first and last days. This may be consistent with previous findings that predictability increases during learning of a balance task. Results also indicate the need to identify the correct physiological interpretation of single or multiscale entropy measures. Further investigation is needed to establish if entropy differences are causally related to performance and learning advantages of the external focus.

Expert and Novice Performers Respond Differently to Attentional Focus Cues for Speed Jump Roping.

Directing attention to an external focus has been shown to facilitate motor performance. For expert performers, however, results have been mixed. Additionally, little is currently known about how focus cues affect the performance of complex continuous whole-body coordination tasks involving object manipulation such as jump roping. The purpose of this study was to examine the effects of attentional focus cues on single-rope speed jumping by experts and novices. The cues directed attention toward the upper (UP) or lower (LB) body and either internally (IN) or externally (EX). Participants (N = 30) completed bouts of speed jumping during a baseline trial and under experimental conditions (UPIN, UPEX, LBIN, LBEX). Jumps and errors were recorded for each trial. Number of jumps (NJ) and errors (NE) were analyzed using separate Friedman’s Tests comparing for each group to compare trials, with Wilcoxon Signed-Rank Tests for post hoc comparisons. Cumulative number of jumps (CNJ) and errors (CNE) for each condition were compared using separate Friedman’s Tests with Wilcoxon Signed-Rank Tests for post hoc comparisons. For experts, baseline NJ was significantly higher than NJ for each trial under the UPIN, UPEX, and LBIN conditions. No differences between baseline NE and any trials were detected. Additionally, no differences were detected between conditions for NJ or NE. For novices, baseline NJ and NE were significantly higher and lower, respectively, compared to Trial 1 under the LBEX condition. Both the UPIN and UPEX conditions produced higher CNJ and lower CNE than the LBIN and LBEX conditions, respectively. Results showed that experts and novices responded in distinctly different patterns to the four conditions. Experts showed degraded performance under the UPIN, UPEX, and LBIN conditions whereas novices only showed temporarily degraded performance under the LBEX condition. These findings may reflect differences in mastery of whole-body coordination and are partially consistent with the Constrained Action Hypothesis (CAH) despite not supporting specific predictions related to the benefit of external focus cues.

The Effect of Attentional Focus and Frequency of Feedback on Performance and Kinematics in Basketball Free Throwing

Introduction: The purpose of this study was to investigate the effect of attentional focus and frequency of feedback on performance and kinematics in basketball free throwing. Materials and Methods: In this semi-experimental research, fifty students were randomly selected using convenience sampling method, and were randomly divided in one control and 4 experimental groups (internal focus and 33% feedback, internal focus and 100% feedback, external focus and 33% feedback, and external focus and 100% feedback). Experimental groups conducted six blocks of ten attempts (every day two blocks of ten attempts) in one week, and in three sessions of training, and received internal or external focus feedback with the corresponding frequency (33% or 100%). After 72 hours, retention and transfer tests were performed with ten-attempt blocks. Performance (throwing accuracy) and kinematic data (joint angle and range of motion) were collected. Data were analyzed using ANOVA with repeated measures and one way ANOVA. Results: Feedback with external focus (100% and 33%) was more effective in improving throwing performance in retention and transfer tests (P < 0.050). Kinematic data analysis showed that external focus feedback groups had the least maximum flexion in the knee joint in retention test compare to acquisition stage (P < 0.050). Moreover, external focus groups had the least maximum flexion at the knee in retention test compared to internal focus groups (P < 0.050). In range of motion of the knee, external focus groups had more range of motion in retention and transfer tests compared to internal focus groups (P < 0.050). Conclusion: Performance improvement in external focus groups may be limited to certain changes in kinematic data, and in line with constrained-action hypothesis.

THE EFFECTS OF ATTENTIONAL FOCUS ON THE PERFORMANCE OF VOLLEYBALL JUMP SERVE IN ELITE PLAYERS

Evidence of the last few years demonstrated that the far external focus of attention would lead to better motor performance (e.g., Mc Nevin., et al, 2003; MacKay and Wulf, 2012). According to the Frequency of Movement Adjustment analysis evidence of “Constrained Action Hypothesis”, the aim of this study was to examine the effects of different attentional focuses on the performance of a manipulative-complex motor skill in highly skillful athletes. 12 professional volleyball players completed a 4 blocks of 8 trail (4 trail for accuracy, 4 trail for effectiveness) of jump serve in four experimental conditions (Non-Instruction, Internal focuses on hand movement, Near external focuses on ball, and Far external focuses on target zone or player). The data of accuracy, effectiveness, and self-perception of the performance was acquired by pointed target areas, analyzing volleyball serve effectiveness method, and self-rated manipulative check, respectively. Results of ANOVA with repeated measures showed that accuracy scores, effectiveness, and self-perceived performance of volleyball jump serve in far external condition was better than near external and internal conditions. In addition, the significant differences between non-instructional and far external conditions were observed only in self-perceived performance. In general, these results confirmed recent findings regarding the detrimental effects of internal focus of attention and the facilitative effects of external focus of attention, especially far external on skilled performance. Article visualizations:

Investigating the Constrained Action Hypothesis: A Movement Coordination and Coordination Variability Approach

ABSTRACTThe purpose of this study was to examine the effects of focus of attention cues on movement coordination and coordination variability in the lower extremity. Twenty participants performed the standing long jump under both internal and external focus of attention conditions. A modified vector coding technique was used to evaluate the influence of attentional focus cues on lower extremity coordination patterns and coordination variability during the jumps. Participants jumped significantly further under an external focus of attention condition compared with an internal focus of attention condition (p = .035, effect size = .29). Focus of attention also influenced coordination between the ankle and knee, F(6, 19) = 2.87, p = .012, effect size = .388, with participants primarily using their knees under the internal focus of attention, and using both their ankles and knees under the external focus of attention. Attentional focus cues did not influence ankle-knee, F(1, 19) = 0.02, p = .98, effect size = .02, or hip-knee, F(1, 19) = 5.00, p = .49, effect size = .16, coordination variability. Results suggest that while attentional focus may not directly influence movement coordination condition, there is still a change in movement strategy resulting in greater jump distances following an external focus of attention.

The Role of Vision and Movement Automization on the Focus of Attention Effect

According to the constrained action hypothesis, an external focus of attention is beneficial for motor learning due to improvements in movement automization. In contrast, an internal focus of attention interferes with automaticity and decreases the effects of motor learning. This study was designed to test the automaticity assumption of the focus of attention effect within a highly skilled population. We examined the effects of attentional focus on kinematics in rope jumping and visual control. Participants practiced the rope-jumping task over five days of acquisition, which was followed by a retention and transfer test. The findings provided evidence that the learning of the task was improved and automaticity was increased by the external focus compared with the internal focus and no attentional (i.e., control condition) conditions. In addition, these findings indicate that visual attention as a function of attentional focus has a stronger relationship with practice performance rather than with motor learning effects.