When refering to evidence in academic writing, you should always try to reference the primary (original) source. That is usually the journal article where the information was first stated. In most cases Physiopedia articles are a secondary source and so should not be used as references. Physiopedia articles are best used to find the original sources of information (see the references list at the bottom of the article).
If you believe that this Physiopedia article is the primary source for the information you are refering to, you can use the button below to access a related citation statement.
This article discusses gait deviations associated with pain syndromes in the lower leg and foot. While this information focuses on certain regions of the body, remember that the human body functions within a kinetic chain. No one movement is ever completely isolated and without effect on another.[1]
For a review of the gait cycle, please read this article. For an overview of gait deviations, please review this article. To review common gait terminology and definitions, please see this article.
Anatomy Review
The ankle is the part of the lower limb, encompassing the distal portion of the leg and proximal portions of the foot. The ankle encompasses the ankle joint, an articulation between the tibia and fibula of the leg and the talus of the foot.
The foot is the part of the lower limb distal to the ankle joint. It is covered on its dorsal surface by loosely adherent skin. On its plantar surface, it is covered by thick hairless skin that is tough and strongly adherent to the underlying plantar aponeurosis. The foot contains 26 small bones that are designed for weight bearing and force distribution. The bony alignment creates three arches the provide efficient weight distribution while avoiding compression of plantar neuro-vascular structures. The three arches (medial and lateral longitudinal and the transverse arch) together create an architectural vault, which is one of the strongest load-bearing structures known to mankind.[2][3]
Please read the linked article for a more in-depth anatomical review of the Foot and ankle.
Ground Reaction Forces
Example of a vertical ground reaction force.
Ground reaction force is a summation of all the forces transmitted from the ground up into the body.[1] Ground reaction force is influenced from all directions: vertical, anterior-posterior, and medial-lateral. These forces are typically measured and recorded using a three-dimensional force plate.[4]
Example of an anterior-posterior ground reaction force
During walking, the vertical ground reaction force is the largest component of the total ground reaction force. It creates forces greater than a person's total body weight per step. The graphed curve of the vertical ground reaction force consists of two peaks: the passive (weight acceptance as the heel strikes the ground) peak and the active (push off) peak.[4][5] The passive peak is caused by the foot pushing against the ground, whereas the active peak is caused by the active force applied by the foot as it pushes away from the ground. The anterior-posterior ground reaction force includes braking peak and propulsion peak.[4] The unique patterns of these peaks illustrate the load forces at the joints and muscles of the lower extremity. These forces felt throughout the limb can influence the development or exacerbation of musculoskeletal overuse or stress injuries.[5][6]
When interpreting a ground reaction curve, the steeper the curve the more significant the impact forces. The curve on the anterior-posterior curve (the breaking forces) will be negative. In general, the greater the forces, the greater risk for stress or overuse injuries.[1]
Please view the following video for a quick yet detailed overview of ground reaction forces during the human gait cycle. This video provides an excellent visualisation of how ground reaction forces shift in different directions as the person moves through space.
During walking when viewed from behind, should not be able to view the big toe.
The big toe is visible during walking when viewed from behind.
Or when there is an asymmetry in the degree of toe in between the person's lower extremities.
Will occur with hallux limitus or first MTP joint osteoartirits
Can occur due to an anatomically longer leg
Popliteal skin crease is oblique from superolateral to inferomedial
Medially oriented patella
When viewed from behind, medial malleolus is visible but the lateral malleolus is not
Loud foot strike
It is expected for foot strike to emit a sound. The sound is representative of the ground reaction force.
If the sound of the foot strike is asymmetrical between the lower extremities, or between the non-painful and the painful side.
Loud single or double sounds with the same foot strike
Slow cadence with a long stride length
Increased angle of foot relative to the ground (increased PF) with a prolonged heel only period during stance
The heel stays on the ground longer in early stance phase
Heel whip
This is the one gait deviation that occurs between the transition from stance to swing phase.
During walking when viewed from behind, it is expected to see a 5-10 degree rotation of the heel and foot in the transverse plane as the foot comes off the ground.
If the heel whip angle of rotation is greater than 10 degrees.
Also deviant is when the heel whip is greater on one side compared to the other side.
Can occur due to an anatomically long leg
Likely related to muscle imbalances at the hip
Oblique popliteal skin crease
No daylight between the knees
The foot crossing the midline of the body
Signs of excessive wear on shoe bottom under the metatarsal heads where shear or twisting force occurs
Excessive pronation
A bisected calcaneus or shoe heel counter is perpendicular relative to the ground.
When viewed from behind:
Can view two or fewer of the lateral toes
The navicular bone is not visible
When viewed from behind:
Heel of the shoe is lifted off the ground
Bisection of the calcaneous or shoe heel counter is tilted medial relative to the ground
Can view more than two of the lateral toes
If the navicular bone is plantarflexed and ABDucted
Contralateral pelvic drop
No daylight between the knees
Knee valgus thrust
Knee valgus alignment
Oblique popliteal skin crease
Absent windlass effect
ie: increased dorsiflexion of the first MTP joint
During forefoot contact/terminal stance, there is normally 35-65 degrees of first MTP joint dorsiflexion.
When viewed from the side, the proximal first metatarsal bone displaces dorsally or the longitudinal arch rises (the windlass effect)
During forefoot contact/terminal stance, there is greater than 65 degrees of first MTP joint dorsiflexion.
When viewed from the side, if there is the failure of the proximal first metatarsal bone to displace dorsally or the longitudinal arch rises (absent windlass effect)
Excessive pronation
Heel whip
Increased hip extension
Knee extension in terminal stance
Decreased dorsiflexion of the first MTP joint
During forefoot contact/terminal stance when viewed from the side, there is normally 35-65 degrees of first MTP joint dorsiflexion.
During forefoot contact/terminal stance, there is less than 35 degrees of first MTP joint dorsiflexion.
According to a 2004 study[11] published in the Journal of Athletic Training:
A “windlass” is the tightening of a rope or cable.
The plantar fascia "simulates a cable" attached between the calcaneus and the metatarsophalangeal (MTP) joints.
Dorsiflexion during the propulsion phase of gait tightens the plantar fascia around the head of the metatarsal. This tightening of the fascia shortens the distance between the calcaneus and metatarsals to elevate the medial longitudinal arch. This shortening of the plantar fascia is the hallmark of the windlass mechanism principle.
From heel strike to weight acceptance: foot pronation increases the distance between the calcaneus and metatarsals. This lengthening applies tension stress to the plantar fascia.
From midstance through the propulsive phase (i.e. the period from the end of midstance when the heel lifts to toe off[12]): foot supination occurs causing the foot becomes a rigid lever arm using the windlass mechanism to propel gait. As with pronation, forces generated during supination also apply tension to the plantar fascia.[11]
↑Asghar A, Naaz S. The transverse arch in the human feet: A narrative review of its evolution, anatomy, biomechanics and clinical implications. Morphologie. 2022 Dec 1;106(355):225-34.
↑Ahn J, Simpkins C, Yang F. Ground reaction forces and muscle activities during anteriorly-loaded overground walking: Preliminary results. International Journal of Industrial Ergonomics. 2022 Jul 1;90:103328.
↑Shono H, Matsumoto Y, Kokubun T, Tsuruta A, Miyazawa T, Kobayashi A, Kanemura N. Determination of relationship between foot arch, hindfoot, and hallux motion using Oxford foot model: Comparison between walking and running. Gait & Posture. 2022 Feb 1;92:96-102.
↑Kawalec JS. 12 - Mechanical testing of foot and ankle implants. In Friss E, editor. Mechanical testing of orthopaedic implants. Woodhead Publishing, 2017. p231-53.