Jump to content

Foot and Ankle Kinetic Chain

Original Editor - Ewa Jaraczewska based on the course by Ari Kaplan

Top Contributors - Ewa Jaraczewska and Jess Bell  

Introduction

A kinetic chain refers to "the body's intricate coordination of various segments to perform a specific activity involving precise positioning, timing, and speed."[1]

The ankle and foot are the terminal segments of the lower limb kinetic chain and play important roles in gait, absorbing load, transferring force, and propelling the body forward.[2] No part of a kinetic chain works in isolation. When one segment cannot meet the requirements of a task, movement can still occur, but it may be achieved via an alternative route (e.g. a different joint, a different plane, or a reduced range). This alternative route is a compensation.[3] While compensation preserves a task, there may be a reduction in efficiency, and in some instances, it may result in symptoms at other parts of the kinetic chain.

In biomechanics, compensation is described as "the body's natural ability to provide alternative means of performing lost functions, either by the damaged or injured organ itself, or through its takeover by another healthy organ."[3]

Foot and Ankle Kinetic Chain

The foot and ankle have to meet two demands within a single stance period. They must be compliant enough at contact to deform and absorb load at loading response, and stiff enough at push-off to transmit force into the ground during late stance.[1][4]

When those demands are not met, the movement is still achieved, but through compensations elsewhere in the chain. Limited ankle dorsiflexion can, for example, cause valgus collapse of the knee, excessive foot pronation, or increased hip internal rotation, each of which helps the tibia to advance despite limitations in the sagittal plane.[5] Assessment should therefore consider the segment above and below any symptomatic joint, since symptom location does not always indicate the source.[4]

Gait and Foot and Ankle Function

The gait cycle refers to "the time interval between two successive occurrences of one of the repetitive events of walking."[6] It is divided into distinct phases, each characterised by specific foot functions. [6]

Gait cycle

Foot and Ankle Function During Walking

Loading comprises initial contact and loading response; propulsion comprises terminal stance and pre-swing. Mid-stance sits between the two as a transitional phase because the foot is still accepting load in early mid-stance and is beginning to generate stiffness in late mid-stance. One approach is therefore to group early mid-stance with loading and late mid-stance with propulsion. In reality, these events occur almost simultaneously, so it is helpful to focus on the purpose of each phase rather than the boundary between them.[4]

For the same reason, loading and propulsion are best assessed together. A compensation during loading often shows up as inefficiency during propulsion, because a foot that has not accepted load well may not establish the position or the stored elastic energy needed for push-off.[4]

Loading Strategy

Loading begins at initial contact and continues until the contralateral toe leaves the ground (i.e. initial contact and loading response). The contact foot must pronate and dorsiflex in a controlled manner, deforming to absorb impact.

Clinically useful checkpoints during loading include the following:[4]

  • Rearfoot at contact: does the heel strike in slight supination and then absorb force gradually, or does it collapse into rapid, uncontrolled pronation?
  • Medial arch behaviour: is there a controlled drop, an uncontrolled collapse, or almost no drop at all, like in an overly rigid arch that never absorbs force?
  • Tibial progression: does the tibia advance smoothly over a stable foot, or does the foot deviate out of the sagittal plane to compensate for a tibia that cannot advance? This is a common sign of a dorsiflexion restriction.

Clinical takeaway: the loading strategy reflects how the system distributes force,[7] not just how much motion occurs. A small deviation from ideal is not necessarily significant. However, in people who have pain or who haven't improved with previous treatment, these details can be key.[4]

Propulsion Strategy

Propulsion begins as the heel lifts and continues through toe-off (i.e. terminal stance and pre-swing). It requires the foot to resupinate and stiffen. The arch should rise, the first ray should engage, the great toe should extend, and the heel should lift to allow forward progression.[8]

Clinically useful checkpoints during propulsion include the following:

  • Foot stiffness: is the foot becoming a rigid lever, or does it stay soft through push-off?
  • Direction of force: is force being transferred forward, or is it leaking medially outside the sagittal plane?
  • Source of propulsion: does propulsion originate from the foot and ankle, or is the patient substituting with hip hike or excessive trunk movement?

A foot that remains pronated through terminal stance cannot generate the rigidity needed for efficient push-off.[9] [10] A foot that is too rigid during loading absorbs less force and loses the elastic recoil needed to propel forward.[4]

Identifying the Source of a Compensation

The following questions can help identify potential causes of compensation or altered movement:[4]

  1. What does the system lack? Mobility, strength or motor control?
  2. How does it compensate? Which plane of movement is used to get around the restriction?
  3. What do you observe?
  4. What are the resulting symptoms, and which tissues are overloaded as a consequence?

These questions can be applied to any joint and any functional task, not only the foot and ankle.

Compensation Strategies During Walking and Squatting

When a joint cannot move efficiently in the sagittal plane, the body has a limited number of strategies available to achieve forward progression during gait. These strategies include:

  • Frontal plane compensation: collapsing medially, for example through the arch[11]
  • Transverse plane compensation: rotating around the restriction. For example, externally rotating the foot during gait[12]
  • Vertical compensation: bouncing or rising up over the restriction rather than moving through it horizontally
  • Stride/range of motion reduction: shortening the movement required through shortened stride length.[13] This type of compensation is most common in the acute phase after injury

The same logic applies elsewhere in the chain. A limitation in hip extension during terminal stance can be compensated for with a pelvic drop (Trendelenburg), excessive pelvic rotation, vertical bounce or anterior pelvic tilt, or reduced stride length.[4]

It also applies to other tasks. Squatting requires coordinated flexion through the trunk, hips, and knees along with ankle dorsiflexion.[14] A dorsiflexion restriction can cause knee valgus (frontal plane), foot external rotation (transverse plane), forward trunk lean (sagittal compensation to keep the centre of mass over the base of support), heel rise, or limited squat depth. However, similar movement patterns, for example medial collapse of the knee and ankle during a squat, may also be caused by a hip abductor and external rotator strength deficit, or both. Assuming the cause without a full assessment risks treating the wrong link in the kinetic chain.[4]

Clinical Takeaways

Clinicians should consider the lower extremity as a continuous kinetic chain when assessing foot and ankle presentations:[4]

  • An altered or inefficient movement pattern is not automatically pathological, and many people move inefficiently without symptoms. Issues arise when load or volume exceeds what a tissue can tolerate given that inefficiency.
  • The same restriction can produce different compensations in different people, and the same observed compensation can originate from different restrictions, so the cause needs to be assessed rather than assumed.
  • The goal is not perfect mechanics, but matching the mechanical demand of a task to what the patient needs to do.

Summary

The foot and ankle do not operate as an isolated segment. They function within a kinetic chain that must accept load and generate propulsion with each step. When there are limitations in mobility, strength, or motor control anywhere in that chain, the body has a limited number of alternative strategies available: compensating in the frontal or transverse plane, moving vertically over the restriction, or reducing the range of movement required. These compensations shift mechanical stress onto tissues less suited to managing it, which may, over time, produce symptoms. Identifying what the system lacks, how it compensates, what is observed, and how that connects to the patient's symptoms, gives clinicians a way to work back from the presenting symptom to the restriction driving it.

Resources

References

  1. ↑ 1.0 1.1 Almansoof HS, Nuhmani S, Muaidi Q. Role of kinetic chain in sports performance and injury risk: a narrative review. J Med Life. 2023 Nov;16(11):1591-1596.
  2. ↑ Earls J. Understanding the Human Foot: An Illustrated Guide to Form and Function for Practitioners. Human Kinetics; 2025 Dec 3.
  3. ↑ 3.0 3.1 Błażkiewicz M, Wiszomirska I, Kaczmarczyk K, Brzuszkiewicz-Kuźmicka G, Wit A. Mechanisms of compensation in the gait of patients with drop foot. Clinical Biomechanics. 2017 Feb 1;42:14-9.
  4. ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 Kaplan A. Foot and Ankle Kinetic Chain and Clinical Reasoning Course. Physiopedia Plus, 2026.
  5. ↑ Kunz KM, Kirk DG, Wadner J, Martonick NJ. Associations between limited dorsiflexion under load and compensatory hip/pelvic gait patterns in healthy adults. Biomechanics. 2026 Jan 5;6(1):6.
  6. ↑ 6.0 6.1 Kharb A, Saini V, Jain YK, Dhiman S. A review of gait cycle and its parameters. IJCEM International Journal of Computational Engineering & Management. 2011 Jul;13(01):78-83.
  7. ↑ Uritani D, Ogaya S. Opposing effects of foot-loading strategies on patellofemoral and tibiofemoral joint compression forces during walking. Gait & Posture. 2026 Jul 25:110600.
  8. ↑ Kondo M, Iwamoto Y, Kito N. Relationship between forward propulsion and foot motion during gait in healthy young adults. J Biomech. 2021 May 24;121:110431.
  9. ↑ Koho T, Kobayashi A, Kato Y, Akiyama C, Hoshi M, Asao A, Sato T, Horikoshi Y, Sone T, Shiba Y, Nakanowatari T. Plantar force characteristics during walking in older adults with pronated feet: A study using a three-sensor in-shoe system. Journal of Biomechanics Open. 2026 May 19:100004.
  10. ↑ Resende RA, Pinheiro LS, Ocarino JM. Effects of foot pronation on the lower limb sagittal plane biomechanics during gait. Gait & Posture. 2019 Feb 1;68:130-5.
  11. ↑ Fong CM, Blackburn JT, Norcross MF, McGrath M, Padua DA. Ankle-dorsiflexion range of motion and landing biomechanics. J Athl Train. 2011 Jan-Feb;46(1):5-10.
  12. ↑ Gao T, Ma Z, Yang N, Zhang S, Shi H, Zhang H, Ren S, Huang H. The relationship of peak ankle dorsiflexion angle with lower extremity biomechanics during walking. J Foot Ankle Res. 2024 Jun;17(2):e12027.
  13. ↑ Aquino MRC, Resende RA, Kirkwood RN, Souza TR, Fonseca ST, Ocarino JM. Spatial-temporal parameters, pelvic and lower limb movements during gait in individuals with reduced passive ankle dorsiflexion. Gait Posture. 2022 Mar;93:32-38.
  14. ↑ Straub RK, Powers CM. A Biomechanical Review of the Squat Exercise: Implications for Clinical Practice. Int J Sports Phys Ther. 2024 Apr 1;19(4):490-501.
Retrieved from "https://www.physio-pedia.com/w/index.php?title=Foot_and_Ankle_Kinetic_Chain&oldid=382961"