The foot is one of the most unstable structures of the human body with 26 bones, 33 joints and the expectation to carry an entire body of weight, there’s a lot of pressure placed on our main form of transport. In this blog we take a look at the structures further up the chain and how they influence the stresses placed on the foot and eventually lead to injury if not properly addressed.

In today’s social media, computer generated and screen dominated society human movement patterns are changing, we are seated more than we once were, children are coddled into activities less kinetic in nature and even that which was once taught amongst physical education in the primary years of learning has been replaced with decreasingly structured and meaningless purpose – all leading to a muscle imbalance, poor muscle activation, poor body control and an atrophy of the most very basic of physical attributes STRENGTH.

Let’s begin our investigation by looking upon the body’s power generators, the muscles which are now so poorly utilized for the purpose of active movement and over requested to be a glorified cushion for the day to day adventures of work and unfortunately entertainment – The Glutes.

The posterior muscles of the hip joint commonly grouped together as “The Glutes” after the three larger and more superficial prime movers, are responsible for extension of the hip as well as both lateral and medial rotation of the femur. As touched on earlier, the average person in society today has a decreased sub-conscious ability to activate these muscles when required. Quite regularly the hamstrings are used as the primary muscle group for hip extension and the Quadratus Lomborum of the lower back as the primary core stabilizer, which although both important in these actions should in fact be secondary to the glute region when comparing size and position relative to the joints they are acting upon.
A decrease in neuromuscular connection, activation ability or comparative strength to the opposing muscle within the gluteal region may lead to conditions being prominent within an athlete or patient associated with internal lower limb rotation, external rotation of the lower limb and quadriceps region dominance, detailed in the table below. At this stage it is important to outline that a singular deficit in a particular muscle group is less likely to cause a pathological movement or complaint, however will be one of a number of both subjective and objective findings which will contribute to the issue.

Glute Region

Muscles Action Deficit Issue Pathological Condition
Piriformis Lateral rotation of the Femur.
Abduction of the Femur.
Extension at the hip joint.
-Internal rotation of the lower limb.
-Hamstring Extension.
-Quad Dominance.
In-toeing

ITB Syndrome
Hamstring Overuse
Medial Knee Pain
Sciatica

Medial Tibial Stress Syndrome
Anterior Tibia Stress Syndrome

Obturator Internus
Gemellus Superior
Gemellus Inferior
Gluteus Maximus
Gluteus Medius Abduct the Femur.
Stabilizes Pelvis.
Internally rotates femur.
-Internal rotation of the lower limb.
-Pelvic Instability- Externally rotates femur
Tibialis Posterior Injury
Increase Pronation
Navicular Stress
Achilles Tendon Injury
Gluteus Minimus
Tensor Fasciae Latae Stabilize Knee in Extension -Decrease Knee Stability Medial/Lateral/Posterior/Anterior knee pain

Quite regularly when the muscles of the glute region are compromised it leads to the muscles of the anterior thigh to become dominant. The primary movements of the anterior thigh muscles are to flex at the hip, bringing the torso forward and placing further weight over the top of the foot; and extension of the knee, which when further utilized over the posterior thigh muscles leads to a locking of the stable joint and increasing the risk of injury as momentum carries over the structure and the body is forced to find the necessary movement at other joints.
However, if the anterior thigh muscles are underutilized it can also lead to conditions in the lower limb. This is not commonly recognized in populations with nil underlying health conditions but can be associated with those who use the posterior thigh muscles when compensating for lack of glute strength. A muscle imbalance around the thigh region once again leads to a pathological rotation of the lower limb which places untoward stress on the associated structures. The Illiotibial Band, a connective tissue overlying the lateral thigh is one of the structures which can become inflamed or injured with excessive rotation. Additionally, the anatomy distal to the knee can become at risk due rotation acting upon the tibia and further down the chain at the foot increasing pronatory forces. Compromise of the muscles in the glute and posterior thigh region can also increase the amount of muscle spasm and irritation at sciatic nerve leading to a loss of proprioception, nerve pain and further innovation loss.

Anterior Thigh

Muscles Action Deficit Issue Pathological Condition
Psoas Major Flexes the Thigh at the hip -Increase Hamstring utilization

-Increased pronation

-Poor VMO activation

Anterior Knee Pain
Medial Knee Pain
Gastrocnemius Injury
Popliteus  Injury
ITB Syndrome
Medial Tibial Stress Syndrome
Anterior Tibia Stress Syndrome
Illiacus Flexes the Thigh at the hip
Satorius Flexes the thigh at the hip.
Flexes lower leg at the knee
Rectus Femoris Flexes the thigh at the hip.
Extends Lower leg at the knee
Vastus Medialis Extends the Low Leg at the knee joint
Vastus Intermedius
Vastus Lateralis

Posterior Thigh

Muscles Action Deficit Issue Pathological Condition
Bicep Femoris Flexes leg at knee joint.
Extends and Externally rotates thigh.
Externally rotates leg at knee
-Increased Quad utilization.
– Gastrocnemius Overuse
-Internal rotation
Internal rotation of the lower limb
Medial knee pain
ITB Syndrome
Sciatica
Hamstring Injury
Semitendinosis Flexes leg at knee joint.
Extends and Externally rotates thigh.
Semimembranosis Flexes leg at knee joint.
Externally rotates thigh.
Medially rotates leg at knee
Gracilis Adducts and flexes thigh at hip joint. -Abduction at thigh Lower Limb Abduction
Increased pronation
Tib Post Injury
Pectineus Adducts and flexes thigh at hip joint.
Adductor Brevis Adducts thigh at hip joint.
Adductor Magnus Adducts thigh at hip joint.
Medial rotates thigh
-External rotation at the hip Lower Limb Abduction
Increased pronation
Tib Post Injury
Adductor Longus Adducts thigh at hip joint.
Medial rotates thigh
Obturator Externus Laterally rotates the thigh

The extrinsic muscles of the foot, those which begin in the lower leg and cross the ankle joint into the skeletal structure of the foot are those most attributed to the cause of foot pain of all the proximal muscles. Both the posterior and anterior leg muscles are responsible for the actions which take place upon the medial and transverse axis of the foot.
The posterior leg muscles, referred to in laymen terms as the calf muscles are responsible for the plantar flexion of the foot and at times flexion of the knee. A lack of strength and flexibility in the posterior leg muscles can lead to poor propulsion due to a decrease in dorsiflexion at the ankle joint. Additionally, overuse injuries are quite frequent within this muscle group as these smaller muscles are called on to be a person’s primary mode of transport in day to day life. Tibialis Posterior weakness is a common observation seen within the excessive pronation population; this muscle is responsible for inverting the foot as well as slowing the pronatory forces which are occurring at foot at any given time. If the muscle does not maintain the strength to support the medial longitudinal arch or resist the pronatory movement further pathological implications can occur.
The anterior muscles of the lower leg, which are often described by patients as “the shin”, grouping it with the laymen term for the tibia bone, fall laterally to the bone itself. These muscles are responsible for the action of dorsiflexion and eversion at the foot as well as extension of the toes. An inability to dorsiflex appropriately for ground clearance during gait can lead to falls within both the young and older populations. While ankle equines in children is usually seen to be a bony block or calve tightness associated with over activity and is easily addressed; in the older population the strength of the muscle to perform the task at hand is found to be in a deficit, this at times can in fact be life threatening.
Similarly, if the anterior toe extensors are too active and causing a retraction of the toes the risk of falls is once again increased. Toe retraction can be linked to inter-digital neuritis, compressing the nerves which innovate the small muscles of the foot and reducing proprioception to the area.

Posterior Leg

Muscles Actions Deficit Issue Pathological Condition
Gastrocnemium Plantarflexes foot and flexes knee -Poor Landing Mechanics
-Poor Propulsion
– Excessive Supination
Dorsiflexion Equinus
Achilles Tendon Injury
Bursiitis
Severs
Posterior Compartment Syndrome
Tib Post Tendon Injury or Dysfunction
Nerve Entrapment
Lateral Loading of the foot
Plantaris Plantarflexes foot and flexes knee
Soleus Plantarflexes foot and flexes knee
Tibialis Posterior Plantarflexes  and inverts foot.
Supports MLA
Popliteus Stabilizes the knee -Excessive Lateral rotation at knee Lateral Ligament Damage
ITB Syndrome
Popliteus Injury
Flexor Hallucis Longus Flexes 1st Toe -Poor Proprioception
– Poor Propulsion
– Poor Balance
Apropulsive gait
Balance issues
Flexor Digitorum Longus Flexes Less Digits

Anterior Leg

Muscles Actions Deficit Issues Pathological Condition
Tibialis Anterior Dorsiflexion and Inversion Equinus
Increased pronation
Poor Foot Clearance
Lateral Foot Pain
Rapid Pronation
Peroneal Tendon Injury
5th Metatarsal Injury
Anterior Compartment Syndrome
inter-Digital Neuritis
Sesamoid Pain
Medial Tibial Stress Syndrome
Anterior Tibia Stress Syndrome
Fibularis Teritus Dorsiflexion and Eversion Increased lateral Loading
Foot Clearance
Peroneus Longus Plantarflexion and Eversion
Peroneus Brevis Plantarflexion and Eversion
Extensor Longus Dorsiflexion and Extension of 1st Toe Digit Retraction
Extensor Digitorum Dorsiflexion and Extension of lesser toes

In conclusion, it has been well established that the feet can affect muscles, joints and other structures further up the chain of command, if a joint is unable to produced the required range of motion for a particular action, it will look for it at other body areas, whether this is optimal for performance or not. Similarly, if the larger structures of the body which are situated close to the Centre of Mass do not have the strength to support, control or activate purposely; then the structures placed distally to the body will receive untoward force and in turn may result in overuse injury or acute damage.

During the month of March we look at Cycling and how as a podiatrist we can make adjustments to the feet as well as the proximal structures to help develop the best possible ride for an athlete who is producing open chain movements in a closed chain situation.

Jackson McCosker
Director /Chief Editor

References

Brukner, P., & Khan, K. (2007). Clinical Sports Medicine. Mcgraw- Hill Education Pty Ltd.
Dugan, S. A., & Krishna P. Bhat. (2005). Biomechanics And Analysis Of Running Gait. Physical Medicine And Rehabilitation Of North America , 603–621
Michaud, T. (2011). Human Locomotion: The Conservative Management of Gait Related Disorders. Washington: Newton Biomechanic.

MILNER, C. E., FERBER, R., POLLARD, C. D., HAMILL, J., & DAVIS, I. S. (2006). Biomechanical Factors Associated with Tibial Stress Fracture in Female Runners. Applied Sciences , 323 – 328.

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