THE BRAIN LEARNS TO LIFT: THE SCIENCE OF MOTOR SKILL ACQUISITION IN STRONGMAN | Episode 2: Perception–Action Coupling in Strongman Implement Handling

From raw strength to skill: the learning problem

A log, an Atlas stone, and a pair of farmer's walk implements can have comparable mass yet demand different ways of perceiving and controlling the world. Whereas a barbell offers a familiar bar and a relatively predictable mass distribution, a large or unstable object changes contact points, hand placement, available space, and locomotor dynamics. The athlete does not simply see an object and then execute a fixed plan. Visual, tactile, and proprioceptive information continually shape the action, while the action itself generates fresh information. This episode explores that perception–action loop, distinguishing experimentally established principles, biomechanical observations in strongman, and cautious practical extrapolations [1–4].

Perception is part of movement, not merely its preparation

Perception and action are not completely separate operations in which an athlete first constructs a picture of the world and then mechanically executes a finished plan. In everyday movement, action changes the information that becomes available. Approaching a stone alters the angle from which its outline is visible, touching its surface reveals friction, and the first moments of lifting make its inertia perceptible. Such signals help shape action, which then generates additional signals. Perception–action coupling describes this mutual dependence. It does not mean that memory and prediction should be ignored, nor that every movement can be controlled entirely through reactions to currently available sensations. Contemporary theories differ in how they explain internal representations and information in the environment. Those differences can generate useful questions without requiring a coach to adopt one exclusive theoretical allegiance. In strongman, the practical questions concern the information that supports appropriate action selection, how that information changes during effort, and what limits arise when an implement moves rapidly or sensory signals arrive too late for a full correction. The movement should not be judged only by the starting posture. Its capacity to adapt as new information becomes available is also important [1,2,6].

One influential concept in ecological approaches is the affordance, an opportunity for action emerging from the relationship between environmental properties and the capabilities of an organism. The same Atlas stone may be manageable for an athlete with long arms and difficult to grip for another with a shorter reach. A loading platform may be accessible in one way with an 80-kilogram object and require a very different strategy with a 160-kilogram one. An affordance is not a fixed label attached to an object, such as 'liftable stone.' It depends on athlete, context, and moment. This helps explain why the same named exercise need not have an identical solution for everyone. A coach can examine whether foot and hand placements allow the athlete to move the implement effectively instead of mechanically copying a champion with different proportions. A key distinction remains: the conceptual usefulness of affordances does not prove that every training method derived from ecological dynamics outperforms alternatives. Methodological discussion and criticism show that this perspective is an active scientific framework, not a settled list of universal prescriptions. Its applied value is best examined through testable hypotheses about which information and constraints change the athlete's behavior [7,8].

Vision provides more than a static image before contact. As we move, the pattern of motion across the retina supplies information relevant to direction, distance, and self-motion, a topic studied under the concept of optic flow. During a farmer's walk, an athlete monitors the route, barriers, markings, and distance to a turn while peripheral visual information supports orientation. Constantly looking down may change access to route information, but maintaining an unwavering gaze straight ahead is not automatically optimal for every course. Before picking up a stone, vision helps estimate size and organize the approach. Once the implement is close to the torso, some visual information becomes less accessible, increasing the practical importance of touch and proprioception. During a log clean, handle position, rotational clearance, and the destination of the implement must all be considered. These examples do not establish one universally correct gaze direction. A rigorous test would require assessing where the athlete looks, which information is used, and how performance responds. What can be said with confidence is that vision for action is selective, dynamic, and adapted to locomotion and manipulation demands rather than a fixed internal photograph [5,6].

Contact with equipment produces crucial tactile information. Cutaneous mechanoreceptors respond to pressure, deformation, vibration, and events that can signal impending slip. During ordinary object manipulation, the nervous system coordinates grip force with the force needed to lift and employs expectations about object properties. Much of this evidence comes from precision manipulation using objects far smaller than strongman equipment. The general principle of sensory contact is relevant, but exact forces or response timings cannot be transferred numerically. With a thick axle, friction, hand position, and the inability to fully close the fingers change gripping demands. With farmer's handles, surface texture and load oscillation can continually modify pressure distribution. On an Atlas stone, texture, dust, moisture, and permitted grip aids all affect contact. Touch also supports active exploration: a small hand adjustment may reveal how stable a contact is. Under extreme loading, however, such exploration should occur under controlled conditions rather than by deliberately losing grip. A tactile principle derived from lightweight object studies is not a license to experiment dangerously with competition weights [1,3,13].

Proprioception supplies information about body position and movement, while vestibular signals contribute to orientation and stabilization relative to gravity and acceleration. Under a yoke, an athlete cannot visually monitor every joint or contact point. Steps, trunk organization, and load oscillations must be regulated using combined information. Proprioception is not an infallible map: fatigue, changing pace, or unusual weight distribution may alter position sense and corrective requirements. Nor can balance be reduced to an isolated property of the inner ear. It emerges through cooperation among sensory information, muscular forces, and ground interaction. In a sandbag carry, anterior placement of mass can alter postural organization relative to farmer's handles held at the sides. A coach observing one repetition cannot precisely diagnose the separate vestibular, visual, and proprioceptive contributions. Instead, responses to controlled changes in route, speed, and implement can be observed without dangerous perturbations. The goal is resilient coordination under relevant conditions, not the arbitrary training of a single sense based on an oversimplified explanation [2,5,9].

The actual object: mass, geometry, contact, and anticipation

Mass is only one mechanical property of an implement. Two objects weighing 100 kilograms can demand different control because their shape, mass distribution, and gripping points differ. The center of mass helps describe translational movement, whereas moment of inertia expresses resistance to changes in rotation about a particular axis. A cylindrical log and a barbell of equal mass do not rotate identically because geometry and handle positions change lever arms and the application of torque. In a homogeneous spherical stone, the center of mass may be relatively straightforward to estimate, yet the absence of handles radically alters the relation between contact and traction. A deformable sandbag may change shape against the body or allow internal contents to shift, further complicating control. These properties are physical realities independent of athletic intention. Learning concerns how the nervous system anticipates and handles their consequences. It does not follow that each implement demands a completely separate neural pathway: some control relationships are shared and others are task-specific. Mechanical analysis should begin with implement geometry and contact positions instead of assuming that equal mass creates equal technical difficulty. For coaching, this distinction prevents absolute weight from becoming the only measure of challenge [2,3,4].

Anticipatory grip control illustrates the relationship between experience and prediction. When lifting a familiar object, the nervous system can adjust grip force in advance in relation to expected lifting forces and then use tactile information for corrections. Precision-grip experiments show that people can learn object properties from size or other cues associated with weight. That does not mean an athlete can accurately know the mass of every new implement before touching it. Vision offers an estimate, previous experience generates expectations, and the first moments of movement provide information for revision. During farmer's walks, excessive grip force may waste effort, but inadequate force risks dropping the implement. The effective balance depends on load and handle surface. A thick axle changes even the geometry of finger contact. Direct numerical transfer from laboratory objects weighing a few hundred grams to competition implements would be inappropriate. The useful principle is narrower: knowledge of object properties can guide force before all consequences are sensed, and experience may refine that anticipation. Serious grip analysis therefore requires more than instructing every athlete to 'squeeze as hard as possible' regardless of context [1,13].

Perceived heaviness is not always identical to the mass measured on a scale. The size–weight illusion shows that, when two objects have equal mass, the smaller one may feel heavier. This longstanding research topic reminds us that visual expectations and prior experience can influence judgments about effort and objects. We should not claim, however, that this illusion explains every strongman athlete's impression that a stone feels unusually heavy. In competition, surface friction, diameter, grip placement, and fatigue provide real mechanical and physiological explanations that may coexist with perceptual expectations. Experiments also show that lifting forces can adapt while the perceptual illusion persists, suggesting that the feeling of weight and motor force control are not identical processes. The practical lesson is not to dismiss heaviness as imaginary but to avoid treating subjective heaviness as a precise measuring instrument. If a bulky stone 'feels' different from a compact one, coaches should first examine geometry, contact conditions, and mechanical demands. A change in perceived weight is not by itself evidence of deterioration in training status. Laboratory weight-perception tests should not be promoted as stand-alone diagnostic tools for competitive technical quality [10,14].

Object manipulation is organized around mechanical contact events and transitions between phases. A hand reaches a handle, contact is established, an object leaves the floor, is transferred to another body position, and finally reaches a platform or is released. Research on tactile control explains how the nervous system uses contact events to select and modify the control of subsequent action phases. This perspective is valuable when analyzing Atlas stone loading. Hand positioning, initial pull, contact with the lap, repositioning, and final extension are not merely static poses. They are transitions during which new information becomes available. An athlete can anticipate contact with the thighs and prepare the next phase, but if the stone slips or rotates unexpectedly, the action must adapt. Faster transitions provide less time for large reactive corrections, making anticipation functionally important. This does not imply a distinct anatomical controller for every phase or that every transition is consciously recognized. Instead, phase analysis can identify where useful information is lost and where predicted contact differs from actual contact. Coaching feedback can be organized around those events without turning execution into an exhausting sequence of verbal commands [1,2].

A biomechanical investigation divided the Atlas stone lift into recovery, initial grip, first pull, lap, and second pull phases. This classification supports more precise discussion of mechanical and perceptual demands. During the first active lift, the athlete establishes contact on a handle-free surface and must transmit force through that interface. In the lap, the stone receives temporary support in a different configuration, allowing trunk and limb organization for final extension. Approaching the loading shelf, target height and maintained contact influence success. The researchers reported changes in joint angles and phase durations as repetitions progressed while stone mass was increased. Those differences cannot be attributed exclusively to fatigue because load changed at the same time. Kinematic measurement also does not directly reveal the tactile sensations guiding every decision. It can, however, support testable hypotheses. If an athlete regularly loses the stone when moving into the lap, inadequate anticipation of contact may be involved, rather than insufficient strength alone. Testing that idea requires comparable attempts and careful observation at the transition. Biomechanics describes the event, while perception science helps frame the intervention question [3].

How perception differs across strongman events

The log clean and press demonstrates why object perception and force production cannot be separated. Cylinder diameter, handle placement, contact with the abdomen or thighs, and available rotational clearance constrain the clean. The athlete must anticipate the implement's movement relative to the body, particularly during the transition into the rack. Familiarity with a barbell grip does not automatically provide the same sense of torque with a log. A large cylinder may temporarily obscure visual landmarks, increasing the importance of tactile contact and prior experience. During the press, handle orientation and mass position change relations among wrist, forearm, and force direction, which may also alter the perceived balance of the combined athlete–implement system. These are plausible mechanical explanations, not proof of one optimal trajectory or one universal elbow angle. Side-view video can document separation from the body and time to the rack, while direct observation can reveal losses of contact. Coaching cues are valuable when they help the athlete perceive a relevant feature, not simply when they produce a dramatic static posture. Effectiveness should be judged by reproducibility and task demands, rather than rigid conformity to another athlete's movement [2,4].

The giant dumbbell introduces clear asymmetry. The load is controlled unilaterally, and large end masses may be positioned far from the handle. Being able to press the same mass using a conventional dumbbell does not guarantee identical control, because mass distribution, contact with the body, and implement orientation all differ. During the clean, the athlete estimates the path toward the shoulder and when the implement can be stabilized. During the press or jerk, the relationship among force direction, rotation, and center of mass must be managed. A mistake in perceived distance or orientation can require a rapid correction with considerable mechanical consequences. The athlete may orient vision toward a useful external target, but there is insufficient direct evidence for naming one universally optimal gaze location during giant dumbbell events. Technical practice should distinguish shoulder placement from pre-press stabilization when either is the limiting phase. Progression can use manageable loads and configurations representative of competition equipment. Calling any successful unilateral repetition a generic improvement in 'brain coordination' is too vague. The meaningful outcome is whether contact and phase transitions can be reproduced without hazardous emergency corrections [2,4].

Farmer's walk combines handling two separate objects with loaded locomotion. At pickup, the athlete must establish grips and make room for the legs to move. After leaving the floor, the implements may swing relative to the gait cycle. Arm length, handle configuration, object inertia, and course obstacles change the available actions. Biomechanical studies of loaded carries identify stride length, stride rate, and ground-contact duration as relevant performance variables, but they do not establish one gait recipe for every load and athlete. One competitor may lose time in the opening meters because pickup is poorly organized and then move quickly; another may start strongly yet lose rhythm at the turn. Segment-level analysis is therefore more informative than one overall time. Perceptually, the athlete integrates handle contact, changing body orientation, and visual route information. Grip force and gait control should not be assumed to operate independently: adjusting one can influence the other. Nevertheless, a precise causal link within a specific athlete must be tested rather than inferred automatically from an association between two measurements [4,9].

The yoke walk distributes load differently from farmer's carries. A frame rests across the upper trunk, while suspended masses can oscillate in response to stepping rhythm. A study involving 19 strongman competitors examined five-meter intervals of a 20-meter course using loads set relative to individual performance. This approach provides a useful model for segmental analysis because initial acceleration and later movement at a more stable pace are not identical. An athlete may perceive frame motion through shoulder pressure and the small adjustments required to limit oscillation. Looking only at the feet does not fully explain control because frame motion and stepping influence each other. Simply instructing someone to 'walk faster' may not solve the problem: increasing stride frequency can change system stability and ground-contact time. A coach can identify where stops occur and whether oscillation increases before them, then cautiously test a moderate change in stepping strategy. Such intervention remains contextual rather than universally demonstrated. Descriptive findings help frame questions but do not justify prescribing an identical stride rhythm to all competitors [4,9].

Sandbag carries, Husafell carries, and other frontal transports emphasize surface contact and object geometry. A bag can deform under pressure, while a Husafell-style stone may require an embracing grip around an irregular volume. In both cases, mass carried anterior to the torso changes postural demands. The athlete must assess object height, breathing and walking efficiency, and locations where slipping is likely. A strategy that works with a compact rough bag may fail with a smoother, bulkier bag of equal mass. Repeated experience may improve detection of small contact changes, but that does not mean one isolated sensory system is being trained independently. A recent comparison of farmer's and Zercher carries suggests that load position affects biomechanics, yet any inference must respect sample characteristics and the specific tasks measured. Such findings cannot be converted directly into prescriptions for every strongman event. When contact and stability are the main limitations, progression through relevant materials and sizes may be more informative than increasing mass alone, provided variations preserve technical control and avoid unnecessary near-failure attempts [4,11].

Sensory uncertainty and designing practice

Different sensory sources are not equally informative in every situation. When a route is clearly visible, visual information can guide locomotion. When a stone blocks the athlete's view close to the chest, contact sensations and estimates of limb position become more important. When a handle is especially rough, the grip force needed to prevent slipping may differ from the force required on a wet surface. Motor control must operate under uncertainty because no sensory channel supplies perfect measurement. Sensorimotor research uses probabilistic and predictive models to describe how information is combined, but these are mathematical accounts of behavior, not suggestions that athletes consciously solve equations during competition. A practical consequence is that a cue helpful in one event can become unhelpful in another if the relevant information is absent or means something different. During a turn in farmer's walk, spatial landmarks change rapidly. During a log clean, object–body relations transform on the way to the rack. Coaching can reduce uncertainty through clear targets and explanation, but it should not replace all firsthand information with external instructions. Skilled performance also requires selecting the information most relevant at each moment [1,2,5].

A constraints-based approach proposes systematically changing characteristics of the task, environment, or performer to explore movement solutions. In strongman, this might involve a modest change in stone-platform height, handle configuration, or walking distance. Such a modification is useful only when it alters information or coordination relevant to the problem being studied. If the limitation is finding a reliable grip, a slightly altered surface can reveal the chosen strategy. If the limitation is acceleration under a yoke, shorter efforts may help isolate the initial phase. Yet an intervention is not effective simply because it carries the label 'constraints-led.' Its rationale should identify what variable changes, what behavioral response is expected, and how retention or transfer will be examined. Under extreme loads, adding constraints should never become an unnecessary test of risk tolerance. Ecological dynamics emphasizes representative practice, but its general claims and some applied recommendations have also attracted criticism. A responsible interpretation uses the framework to generate hypotheses and remains willing to revise them when observation fails to support prediction [7,8].

Representative practice does not mean reproducing every aspect of competition in every training session. It means preserving important relationships between available information and required action. A very light dumbbell with different handles and proportions might allow approximate movement rehearsal without reproducing the contact challenges of the actual event. Conversely, practicing continuously with competition loads may be too costly to allow sufficient repetition. Coaching therefore requires compromise. Some sessions permit technical exploration under manageable conditions; others assess performance with the target equipment. When substitutes are chosen, the preserved feature should be explicit: handle thickness, mass distribution, contact path, or distance. No substitute serves every goal perfectly. A sandbag is not an Atlas stone merely because both are heavy and carried in front of the torso. It may, however, reproduce selected demands of anterior loading and object control. Final validation must occur on the intended implement rather than exclusively on the exercise used for preparation. This prevents familiarity with an accessory exercise from being confused with the competition-specific skill [3,4,7].

Video feedback needs context; it is not a visual oracle. Side-view recordings can reveal movement in the sagittal plane but may conceal transverse rotation or pressure distribution beneath the feet. A frontal view shows apparent symmetry yet cannot directly quantify internal joint torques or sensory strategy. Inertial sensors provide other motion data, with limitations related to calibration and interpretation. Useful analysis begins with an observable question. Where does the stone begin to slip? How many steps are required before the yoke becomes stable? When does the log angle change relative to the torso? To compare sessions, preserve as many conditions as possible: implement mass, equipment, preparation, distance, camera position, and instructions. If those conditions differ, interpretation must be cautious. Perceptual information is also partly subjective, so the athlete should be asked what contact felt like. Disagreement between sensation and video can guide further investigation without either source being assumed infallible. Technology supplements critical observation and communication but does not replace them or the assessment of physical risk [1,3,9].

Learning to grip an implement can be evaluated through more than whether it falls. Excessive squeezing, repeated hand adjustments, or slipping at predictable moments may indicate how the athlete regulates contact. Such observations remain ambiguous without information about load, friction, and fatigue. A simple gym comparison could use two suitably manageable surfaces, the same mass, and a comparable task to ask whether the athlete detects useful differences before major slip occurs. Another observational test might vary walking distance within a safe range while preserving handle design, examining whether grip adjustments remain effective during locomotion. These procedures are not presented as clinically or competitively validated for every category of strongman athlete; they are applied observation methods. If pain, repeated loss of control, or dangerous last-second corrections occur under heavy loads, testing should stop. The aim is not to maximize errors but to identify information supporting safe, repeatable actions. Perception–action theory becomes operational when a hypothesis is stated, a meaningful comparison is preserved, and the outcome is monitored independently of the theoretical story [1,2,3].

Perceptual transfer in competition, assessment, and conclusions

Competition information does not remain constant. A turn changes visual landmarks, the combined system accelerates in a new direction, and ground contact duration may differ from the previous step. During a farmer's walk with a turn, an athlete may reach the marker quickly yet lose seconds by failing to position the implements before reversing direction. That is not exclusively a matter of 'foot speed,' since the trajectory of both objects must be anticipated while grip remains secure. During a truck pull, visual landmarks and tension felt through a harness or rope can convey information about movement onset, while resistance varies among vehicles and surfaces. In a tire flip, the transition from pushing to repositioning the hands rapidly changes tactile information. Coaching should therefore identify critical interactions between object, body, and environment rather than treat every event as one uniform effort. Direct experimental evidence is insufficient to quantify the contribution of each sensory channel in these particular tasks. What can be done is to film transitions, measure segment times, and test whether changing a visual landmark or approach strategy reproducibly changes the result. If it does not, the original hypothesis may be wrong. This is the strength of disciplined observation: theoretical explanations do not excuse outcomes that fail to materialize [4,5].

An illustrative six-session learning sequence for an unfamiliar implement can begin by identifying its physical properties before heavy attempts. In session one, the athlete examines geometry, contact points, and surface conditions, followed by manageable attempts that do not seek failure. In session two, the same object is used to examine whether starting position, pickup, and the first secondary contact can be reproduced without constant instructions. In session three, the coach cautiously changes one property, perhaps target placement or course length, to observe adjustment. Session four returns to the original condition and seeks evidence of retention and fewer unnecessary corrections. Session five introduces a controlled variant closer to competition, and session six repeats the original assessment after a delay. This is an educational design example, not a validated strongman training protocol. Session count, loading, and training volume must be individualized because tissue tolerance and prior experience differ. Records should include object geometry, surface, mass, visual landmarks, instructions, error events, and the athlete's perception of contact. The purpose is to relate performance changes to observable information and actions rather than to assume hidden changes without evidence [1,3,4].

To assess whether perception has become more functional, tests must differ from heavily assisted learning. An athlete who performs well only when a coach states exactly when to move the hands may be successful without being independent. A delayed attempt under the same conditions without prompts provides different information. A second test with a similar but not identical implement can probe generalization. Changing every property at once should be avoided because interpretation then becomes difficult. One failed lift also cannot diagnose sensory function: strength limits, fatigue, emotion, or strategy may be responsible. Assessment can combine timing, video, phase success, and subjective reports of contact. Each captures a different aspect of the event. An objective number is not necessarily a valid measure for every question. For example, average speed over 20 meters cannot fully represent anticipation during a turn. Conclusions should rest on convergence among observations that can be reproduced. The gym becomes a place for disciplined inquiry without pretending to possess the measurement capabilities of a neuroscience laboratory [2,4,9].

Theories of perception–action coupling are useful partly because they discourage easy explanations. If an athlete misses a stone, it is not scientifically meaningful to announce that the brain 'failed to activate,' that proprioception is absent, or that an affordance was not perceived. Such labels do not identify a measurable cause. The coach should first examine force capacity, grip security, implement placement, and approach to the target. Only then should a specific hypothesis about information or anticipation be developed. The same principle applies to claims about 'natural' or 'instinctive' techniques: intuitive movement can work in one setting and fail in another. Debates between computational and ecological accounts remain relevant, but they need not become a conflict between scientists and practitioners. Predictive models explain some forms of calibration; ecological approaches emphasize information available through interaction with the world. Both must answer to data. Strongman is particularly interesting because of its varied equipment, yet direct research on perception in elite competitors remains limited. Precisely stating what is known and unknown is evidence of scientific rigor, not a failure of coaching confidence [2,6,7,8].

A further error is treating measurements from one event as prescriptions for every other event. A fast farmer's walk does not guarantee efficient yoke walking because contact and oscillation differ. A strong log clean does not ensure an effective giant dumbbell clean because unilateral control changes the task. An easy small stone does not establish safety with a much larger implement. Still, certain functional elements may be shared: estimating contact timing, organizing steps, regulating forces, and selecting useful visual landmarks. To identify transfer, two tasks should be compared by mechanics and information demands rather than the umbrella label 'strongman.' An applied analysis can identify shared perception–action relations: approaching a target, stabilizing an oscillating load, sustaining grip during movement, or transferring an object between supports. Any proposed improvement should subsequently be tested in the actual target event. There is a meaningful difference between suggesting that an accessory exercise could support a skill and asserting that it necessarily does. Without direct testing, transfer remains a coaching hypothesis [3,4,12].

The conclusion is that strongman equipment is not a collection of abstract weights. Implements are physical systems with surfaces, shapes, inertias, and contact points that athletes must discover and control. Vision, touch, proprioception, and postural orientation interact with prediction and experience, and the relevance of each information source changes during execution. Good technique cannot be defined solely by imitating a static image. It involves detecting useful information and using it for an efficient, reliable, adaptable action. Existing research provides substantial support for general manipulation principles and descriptive kinematics of selected strongman events, but it has not validated one universal perceptual algorithm for the entire sport. The rational next step for athletes and coaches is to ask precise questions about contact, orientation, and transitions, maintain comparable assessment conditions, and test retention and transfer. The following episode will examine the same problem through the body's degrees of freedom: how many joints can be coordinated into a system flexible enough to handle awkward objects yet sufficiently stable to produce large forces [1,2,4].

References and verifiable sources

[1] Johansson RS, Flanagan JR. Coding and use of tactile signals from the fingertips in object manipulation tasks. Nature Reviews Neuroscience. 2009;10:345–359. DOI: 10.1038/nrn2621. https://www.nature.com/articles/nrn2621

[2] Shadmehr R, Smith MA, Krakauer JW. Error Correction, Sensory Prediction, and Adaptation in Motor Control. Annual Review of Neuroscience. 2010;33:89–108. DOI: 10.1146/annurev-neuro-060909-153135. https://pubmed.ncbi.nlm.nih.gov/20367317/

[3] The biomechanical characteristics of the strongman atlas stone lift. 2021. https://pmc.ncbi.nlm.nih.gov/articles/PMC8418215/

[4] The Biomechanics and Applications of Strongman Exercises: a Systematic Review. 2019. https://pmc.ncbi.nlm.nih.gov/articles/PMC6901656/

[5] Fajen BR. Visual Control of Locomotion. Cambridge University Press. 2021. DOI: 10.1017/9781108870474. https://www.cambridge.org/core/elements/abs/visual-control-of-locomotion/64F808850F29D1BDF93CAD89B0BB06C0

[6] Huesmann K, Loffing F. Perception-action coupling in anticipation research: a classification and its application to racket sports. Frontiers in Psychology. 2024;15:1396873. DOI: 10.3389/fpsyg.2024.1396873. https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2024.1396873/full

[7] Araújo D, Lopes H, Farrokh D, Davids K. The ecological dynamics of cognizant action in sport. Psychology of Sport and Exercise. 2025;80:102935. DOI: 10.1016/j.psychsport.2025.102935. https://www.sciencedirect.com/science/article/pii/S1469029225001347

[8] Collins D, Carson HJ, Rylander P, et al. Ecological Dynamics as an Accurate and Parsimonious Contributor to Applied Practice: A Critical Appraisal. Sports Medicine. 2025;55:799–810. DOI: 10.1007/s40279-024-02161-7. https://doi.org/10.1007/s40279-024-02161-7

[9] The Biomechanical Characteristics of the Strongman Yoke Walk. Frontiers in Sports and Active Living. 2021;3:670297. DOI: 10.3389/fspor.2021.670297. https://pmc.ncbi.nlm.nih.gov/articles/PMC8107362/

[10] New evidence for the sensorimotor mismatch theory of weight perception and the size-weight illusion. Experimental Brain Research. 2024. DOI: 10.1007/s00221-024-06849-0. https://pmc.ncbi.nlm.nih.gov/articles/PMC11208202/

[11] A Comparative Biomechanical Analysis of the Farmers and Zercher Carry Exercises. International Journal of Strength and Conditioning. 2026. https://journal.iusca.org/index.php/Journal/article/view/566

[12] Krakauer JW, Hadjiosif AM, Xu J, Wong AL, Haith AM. Motor Learning. Comprehensive Physiology. 2019;9:613–663. DOI: 10.1002/cphy.c170043. https://pubmed.ncbi.nlm.nih.gov/30873583/

[13] Li Y, Randerath J, Bauer H, Marquardt C, Goldenberg G, Hermsdörfer J. Object properties and cognitive load in the formation of associative memory during precision lifting. Behavioural Brain Research. 2009;196:123–130. DOI: 10.1016/j.bbr.2008.07.031. https://pubmed.ncbi.nlm.nih.gov/18722479/

[14] The size-weight illusion and beyond: A new model of perceived weight. 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC12448991/