Proximal Muscle Strength and Foot Injury


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.

Plantar Aponeurosis: Injury, Treatment and Differential Diagnosis


Plantar Aponeurosis Overview

Plantar aponeurosis injury dampens the spirits of all of its victims; from the most elite of athletes to those with sedentary lifestyles and everyone that can be categorized in between. Sportsmen of note who have suffered from plantar aponeurosis injury include AFL stars Robert Harvey, Brad Ottens and Josh Kennedy – of which two have explored some pretty extreme interventions to free them of the pain and get back to the game they love, which will be discussed in our up-coming and first well known athlete interview to be release in the coming days. Before we release that interview however, let’s get an overview of what the plantar aponeurosis is, what the recommended treatment is and the possible differential diagnosis which may be relative to the area.

The plantar aponeurosis or plantar fascia as it is more colloquially known is a flat sheet of thickened, poorly vascularised and poorly innovated, deep fibrous connective tissue of the foot which can measure between 2.2 and 5.4milimetres (Cardina, Chhem, Beauregard, Aubin, & Pelletier, 1996). The broad white longitudinal fibres originated at the medial tuberosity of the calcaneus and insert at the proximal head of the phalanges. Anteriorly, at the metatarsal-phalangeal joints latitudinal connective tissue fibres reinforce the supportive nature of the plantar aponeurosis creating the Transverse Arch of the foot. Similarly, a medial and lateral longitudinal band of connective tissue further support the respective arches while protecting deeper structures of the foot (Brukner, 2013).In younger people the plantar aponeurosis can be intertwined with the achillies tendon which can make diagnosis of some presentations difficult.
The plantar aponeurosis is able to support up to twenty-five percent of the load experienced by the medial longitudinal arch. During dynamic gait the plantar aponeurosis may only elongate up to two percent of its relaxed size however, the stretch tension and isometric contraction which occurs in association with the windlass mechanism acts like a spring moment during propulsion. The windlass mechanism occurs when the first phalangeal dorsiflexes and the metatarsal plantarflexes – stretching the plantar aponeurosis and lifting the medial longitudinal arch height through shortening the distance between the bones of the foot (Michaud, 2011).

Allied Health Professionals regularly see heel pain in patients and very often it is quickly diagnosed as plantar fasciitis or plantar fasciosis without the use of imaging or a sound clinical reasoning for the condition. Many issues arising at the heel have quite similar signs and symptoms and as a result can be misdiagnosed or treated incorrectly.
Common heel pain signs and symptoms may include; localized pain, pain on palpation of the heel, pain with the first steps after rest, tight calves and the occurrence of a sudden impact onset or insidious onset. Differential Diagnosis for heel pain presentation is shown in the table below in addition to possible treatment regime that may be implemented.

Condition Diagnostic Tools/Differences Treatments
Fat Pad Contusion -Pain does not ease with activity
-XR shoes nil signs of spur
-US shows nil signs of increased plantar fascia thickness
– Sudden impact
Icing nightly or when sore

Heat/anti-inflammatory medications or topical creams for prevention of pain

Off-loading of the heel through orthotic devices or poron buttons

Calcaneal Fracture/ Stress Reaction -Pain does not ease with activity
– XR shows sign of fracture
– CT scan shows signs of stress reaction
Off-loading devices including strapping, orthotic devices or orthopaedic boots.
Modified activityweight bearing exercises as soon as achievable
Heel Spur -Pain may or may not ease with activity

– XR shows increase in bone uptake at calcaneal

– Rolling of frozen water bottle daily or when ever sore

– Off-loading of area through taping or orthotic devices including poron buttons

– Self massage through calves and plantar surface of the foot inclusive of foam rolling and spiky ball.

-Stretching of calves and plantar muscles

– Isometric strengthening activities

– Footwear changes can be appropriate

Plantar Fasciitis/ Fasciosis – Initially improves with activity
– US shows increased plantar fascial thickness
– US shows signs of increased inflammation
Plantar Neuritis – Pain is superior-medial of the calcaneal tuberosity
– May be tingling and numbness involved due to nerve irritation

Evidence Regarding Treatment
It was found in a prospective randomized study conducted by (DiGiovanni, Nawoczenski, lintal, Murray, Wilding, & Baumhauer, 2003)that tissue specific plantar fascia stretching showed significantly better results when compared to a generalized calves and achillies tendon based stretching regime. Most notable were the decreases in worst pain measured via VAS score with a p-value = 0.02 and first step function and pain with a p-value =0.006. From these results it can be inferred that the use of non-weight bearing stretching exercises specific to the plantar aspect of the foot creates greater pain reduction than a standard weight-bearing achillies tendon stretching program.
Chew, Leong, Lin, Lim and Tan established in a 2013 randomized trial that both plasma injection and extracorporeal shockwave therapy combined with conventional treatment created more improved outcomes for patient pain and function when compared with conventional treatment as a standalone. However no significant difference was found between ESWT and plasma injection (Chew, Leong, Lin, Lim, & Tan, 2013).
In a 2014 randomized control study by (Suleymanoglu, Esmaeilzadeh, Sen, Diracoglu, Yaliman, & Eskiyurt, 2014)comparing radial shock wave therapy and low level laser therapy for chronic plantar fasciitis it was concluded that both RSWT and LLLT were significantly effective in the decrease of thickened plantar fascia immediately after the 3-month assessment p<0.001. The specific modalities mentioned here are not included in the above table due to practitioner cost, invasive nature and the point that this measure was used after a 6 months non response period to conservative interventions.
When comparing full-length silicone insoles versus ultrasound-guided corticosteroid injection for the management of plantar fasciitis through means of randomized clinical trials, it was found that after one month of treatment both groups had significant improvement of both pain and function related to their foot pain, however those involved in the injection group were found to have statistically significant differences (p<0.005) in VAS, ultra-sonographic thickness of plantar fascia, foot and ankle outcome score for daily living activities and sport and recreation function. However, conclusively it was advised that silicone insoles were used as a first line treatment given the minimally non-invasive nature (Yucel, et al., 2013).
A randomized controlled trial of calcaneal taping, sham taping and plantar fascia stretching in 2006 found a significant difference between calcaneal taping and stretching of the plantar fascia/ sham taping/control in the category of VAS pain (p<0.006) , (p<0.001) and (p<0.001) respectively. Stretching was found to have statistical significance over the control group (p=0.026). It was concluded that calcaneal taping was shown to be more effective as an intervention for plantar heel pain (Hyland, Webber- Gaffney, Cohen, & Lichtman, 2006).
In the event of kinesiology taping for the short term treatment of plantar fasciitis it was found that no significant difference was seen in the either group using kinesiology taping with traditional physical therapy or just traditional physical therapy (Tsai, Chang, & Lee, 2010).
When exploring more invasive treatments plantar fasciotomy with the use of endoscopic or radiofrequency lesioning techniques have been found to be around 70-90% effective, however with any surgical intervention comes risk, in this case both flattening of the medial longitudinal arch and heel hypoesthesia (Davies, Weiss, & Saxby, 1999).

In conclusion it can be seen and so it should be with any presenting complaint that full and comprehensive assessment be complete to best support any clinical reasoning and diagnosis of a specific condition. Furthermore, a holistic approach to treatment is required to ensure an adequate and speedy rehabilitation from plantar foot pain associate with the plantar aponeurosis. Using the highest evidence based interventions in combination appears to provide best outcomes for these conditions.

In our next post we will be discussing plantar fascial injury with two times Brownlow Medallist Robert Harvey as well as diving into his unconventional approach to treating said pain with a brutal home remedy

Jackson McCosker
Director /Chief Editor