Non-Operative Management of Symptomatic Hallux Limitus: A Novel Approach of Foot Core Stabilization and Extracorporeal Shockwave Therapy

Abstract

Background:

This video presents assessment and management of hallux limitus using intrinsic foot strengthening and joint mobilization techniques with combination of extracorporeal shockwave therapy (ESWT).

Indications:

Clinical history includes pain with walking, running, jumping, or loaded plantarflexion localized to the first metatarsophalangeal (MTP) joint. Indications for our treatment approach of hallux limitus include pain localized to the first MTP joint, corresponding lack of active range of motion/passive range of motion, and reduced foot/ankle strength often with joint space narrowing on imaging.

Technique Description:

Our program uses the principle of foot core exercises that enhance intrinsic muscles of the foot to assist in medial longitudinal arch stabilization and hallux strengthening. Progression of these exercises can be done in weight-bearing and impact activities specific to patient goals. In addition to these foot intrinsic exercises, calf raises should be incorporated to strengthen the gastroc-soleus complex to both improve plantar foot strength and facilitate extension of the first MTP joint. Manual therapy techniques reduce the rigidity of the first MTP joint and restore appropriate medial-lateral and plantar-dorsal balance. With severe limitations in mobility or pain limitations, ESWT can be incorporated to treat the joint and surrounding soft tissue restrictions.

Results:

Increased first MTP extension is observed. Reduced symptoms of first MTP joint pain with activity allow patients to return to walking and other physical activities with improved comfort. Complications are rare. Pain over the first MTP joint is expected during ESWT. Rarely, irritation of the plantar components of the first MTP joint, including the tibial and fibular sesamoid bones, may occur.

Discussion/Conclusion:

Non-surgical management of hallux limitus may improve using the described technique of intrinsic foot strengthening with focus on stabilization of the medial longitudinal arch and strategies of improved mobility of the first MTP joint. Adding ESWT may address joint limitations and facilitate gains in exercise and mobility.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

We are presenting non-operative management of symptomatic hallux limitus: a novel approach of foot core stabilization and extracorporal shockwave therapy. Narrated by myself, Tom Reilly, physical therapist, with contributions from Lindsay Wasserman, physical therapist, and Dr. Adam Tenforde.

We have no relevant disclosures.

Symptomatic hallux limitus is a common condition and can be challenging to treat. Recommended treatments often include the combination of activity modification, foot orthotics, trial of analgesics, and consideration of steroid injection. Unfortunately, these treatments often provide temporary relief and do not address the limitations in function of the first metatarsophalangeal (MTP) joint.

Surgical management is often considered for refractory cases, although this may not resolve pain and restore function of the foot. Furthermore, some patients may not elect surgery and have desire to try further strategies to improve their function. As a specialized referral center, we commonly see patients who have symptoms refractory to conventional treatment and desire innovative measures to avoid surgery.

The aim of this report is to describe an innovative treatment approach for patients with hallux limitus.

In the video, we present our exercise program, use of joint mobilization techniques, how to apply extracorporeal shockwave therapy (ESWT), complications to consider, clinical outcomes to measure, and a list of relevant references. Our treatment approach for hallux limitus was developed at Spaulding Hospital Cambridge Outpatient Center (Cambridge, MA) where we commonly treat active individuals with foot and ankle conditions and desire to optimize non-surgical management while returning to high level of sport activity.

Indication for our treatment of symptomatic hallux limitus includes pain localized to the first MTP joint with corresponding lack of flexion and extension localized to the joint that may be accompanied by joint space narrowing on imaging. A clinical evaluation is performed by physicians and physical therapists.

Mobility of the first ray is assessed, including the first MTP joint, tarsometatarsal, and cuneonavicular joints. Hindfoot, including talocrural and subtalar joints, is evaluated and limitations in these joints may result in overall dysfunction of the foot and ankle. Soft tissue restrictions of gastrocnemius, soleus, and flexor hallucis longus (FHL) are also examined.

Foot strength and dynamic control of the medial longitudinal arch are assessed specifically in weight-bearing activities such as walking, squatting, jumping, and running. Single-leg heel raises are also performed to assess strength and available range of motion at the first MTP joint in degree of terminal plantar flexion. In the symptomatic patient, pain is often described at the end range of the heel raise.

Physical therapy exercise program begins with introduction of the foot core exercises to improve intrinsic foot strength as well as encourage the patient to dissociate movement of the first MTP joint and muscles of the hallux complex from the lesser toes. These foot core exercises include toe yoga, toe spreads or abduction/adduction, and doming. The concept of the foot core can be further explored in the reference by McKeon et al at the end of this video.

Toe yoga, involving the dissociation of the first ray from the lesser toes, is performed as the first MTP joint is actively brought into extension and the lesser toes stabilize while maintaining contact on the ground. The patient is instructed to raise the big toe while keeping the lesser toes on the ground. The exercise is then reversed, with the hallux stabilizing on the ground, firing both FHL and flexor hallucis brevis, as the lesser toes extend and lift off the ground.

Toe abduction or toe spread exercises focus on spreading the toes from the midline of the foot. These exercises engage the adductor hallucis that may improve strength and, in theory, counteract forces contributing to hallux valgus deformity. The patient is instructed to spread their toes as wide as possible and then bring them back to midline. Patients often present with limited range during this exercise and toe separators can be prescribed to passively stretch the intertarsal joints, allowing for greater motion and voluntary motor control over time.

Doming is introduced and involves elevating the arch of the foot while maintaining contact of the first MTP joint. This exercise will work the foot intrinsics and help stabilize the arch and the first metatarsal. The patient is cued to firm up the toes and drag the ball of the foot toward the heel, creating and increasing the arch of the foot. It is important to avoid compensation with the use of extrinsic muscles such as long toe flexors and anterior tibialis, and to avoid general foot/ankle inversion observed by rolling to the outside of the foot. Once the patient can perform this in a seated position, progression will move to double limb standing followed by single limb standing.

Dynamic exercise progression is important to implement, especially in the active population, as activities such as running require single limb support during the gait cycle. Patients are instructed in double leg hopping and progressed to single leg hopping. The patient will dome their feet and perform a hop with the goal to minimize knee and hip involvement. The patient is instructed to dome their feet, hop, and then slowly lower their heels to the ground while activating the muscles of the medial longitudinal arch and re-creating the foot dome position with landing.

The patient is cued to land as soft as possible. Hopping should have a primary focus on foot and ankle control, utilizing the gastroc-soleus complex to perform the hop, control heel descent, and assist foot intrinsics to achieve a stable arch as the heel lowers to the ground.

Progressions from this basic hop may include hopping forward to back, side to side, then one foot to the other foot, and eventually to single leg hopping. Box jumps up and down are also utilized in a progression. These progressions will begin to incorporate the entire kinetic chain, including the knee and hip, but focus continues to be on rolling through and utilizing the first ray as well as landing softly with control.

Given the importance of optimizing plantar flexion function that contributes to hallux extension, calf strength is promoted as well. The heel raise is performed by activating the arch and then slowly rising up on the toes. Treatment typically begins with seated heel raises to initiate mobility of the first MTP joint and introduce load to the joint, as well as begin calf activation.

The exercise is progressed to double leg in standing and then to single leg. Range of motion is often reduced initially due to pain associated with hallux going into terminal extension range of motion in standing, but patients are encouraged to go as high as they can tolerate. Maintaining a neutral position of the foot and ankle is important, including reducing the tendency to roll to the outside of the foot in terminal plantar flexion.

Although exercise can assist in improving mobility and maintaining current range, manual treatment is often indicated to improve the osteokinematics at the first MTP joint.

Axial distraction of the first MTP joint is important to initiate range of motion. The therapist stabilizes the first metatarsal and provides axial distraction by holding at the proximal phalanx just distal to the first MTP joint. Early stages of osteoarthritis are often painful with any movement, not just at the end range, and this technique can be helpful to reduce active pain.

If hallux valgus is a component, distraction is performed and hallux valgus is reduced by bringing the proximal phalanx into alignment. Dorsal and plantar glides are then added in to improve flexion and extension of the MTP joint. The therapist will continue to distract, stabilizing at the first metatarsal and holding at the proximal phalanx, as a dorsal glide is performed to improve extension. The therapist will then glide the opposite direction for flexion. The patient can also be instructed on self-mobilization techniques of distraction and dorsal/plantar glides.

In select cases and based on the goals of the patient, chronicity and tolerance to the physical therapy exercises and mobilization techniques, ESWT may be incorporated into the treatment protocol. Radial shockwave generates pressure waves that can be applied over the surface of the first MTP joint. This technique may promote blood flow to the joint and help reduce pain. Radial pressure waves over bone surfaces can be painful and reducing the frequency of pressure wave application can allow for better patient tolerance.

The full joint capsule should be explored during treatment using the principle of clinical focusing, which is described as applying treatment to sites of pain. A typical treatment may include 3000 count of radial pressure waves at 2 to 3 bars at 10 to 12 Hz using different applicator heads. Additional treatment over secondary structures, including the tibial and fibular hallux sesamoid bones and FHL and extensor hallucis longus, may address components of pain from tendon actions on the joint.

Alternatively, focused shockwave can be applied over the joint using a similar technique. The focused shockwave device may be better tolerated during treatment as radial pressure waves generate vibration over bones that cause excess pain in some patients. Typical focus shockwave is applied for minimum of 1000 shocks at 0.10 to 0.25 mJ over similar anatomic areas as radial pressure wave. During shockwave therapy, we generally recommend avoiding use of anti-inflammatory medications due to the theory that triggered inflammation may partially explain the mechanism of shockwave therapy promoting tissue healing, and we do allow for acetaminophen and topical application of ice for breakthrough pain relief.

Minimal complications are expected with both manual and therapeutic exercises. Patients may complain of fatigue or muscle soreness following the exercises. Pain during heel raises may be expected as patient nears full range of motion but modifications to reduce range of motion can be provided. In some cases, irritation of the sesamoids may occur due to the novel load into the first MTP joint. Manual work is often tolerated well, especially when applying traction to the joint.

The use of ESWT is expected to cause pain during treatment and setting patient expectations can help prepare the patient. Postprocedure pain is less common and can be controlled with oral analgesics and icing. In our experience, targeting bone marrow lesions adjacent to the first MTP joint may cause increased temporary pain, in theory, resulting from upregulation of bone remodeling.

Potential outcomes include decreased progression of hallux valgus angulation, improved first MTP joint extension, and pain reduction with both weight-bearing and impact activities. With reduced first MTP joint pain and increased extension, an improved gait pattern can be achieved as the patient will be able to roll over the big toe easier, reducing unnecessary loads to other aspects of the foot. Improving foot strength will also allow the patient to control deformation of the arch through gait and will aid in protection of the hallux. Return to sport and activity should be individualized to the goals of the patient. In general, a progression requires reduction of symptoms as physical activity advances and continued physical therapy exercises and movement strategies are maintained.

We have observed that many patients are able to tolerate demands through the hallux MTP joint and gain ability to return to sport and high-level activities. Our observations are based on clinical expertise and may be substantiated with further studies.