A fundamental feature of the foot often missed in our assessments is first-toe mobility, specifically the metatarsophalangeal (MTP) joint. The first MTP joint should be able to extend as much as 65 degrees, but many people lack full range of motion due to osteoarthritis or injury (Image 1). Limited MTP dorsiflexion may not stop our clients from running around, but the lack of big-toe mobility means the body is forced to compensate further up the kinetic chain. By altering the foot’s natural movement patterns, limited MTP dorsiflexion can lead to “mysterious” knee or hip pain and an unstable gait. Curl your toes and try to walk normally—the change in movement is clear.

During the stance phase of gait, our toes dorsiflex to help raise the arch and provide greater shock absorption. As the arch flattens, the toes, plantar fascia, and associated muscles eccentrically contract via the windlass mechanism (Image 2). This action helps spring the person forward with greater propulsion during push off. However, it only works when there is decent big-toe mobility. With the feet acting as springs, absorbing and transferring the forces of gravity, it should be a remarkably efficient system, but that’s not always the case.

Signs and Symptoms

The stiff and painful osteoarthritic symptoms of hallux rigidus usually occur in older clients, but a sports injury such as turf toe may, in time, lead to reduced range of motion in young adults as well. According to a 2017 literature review, hallux rigidus affects one of every 45 middle-aged people and 35–60 percent of the population older than 65.1 If the brain perceives threat, the joint may become painful in an attempt to offload gravitational stress. This is often the case with a hallux valgus toe, where a bunion forms as the long metatarsal bone shifts toward the inside of the foot and the phalanx bones angle toward the second toe (Image 3).

As for hallux limitus, this condition typically begins with mild restriction of functional range of motion and little MTP joint arthrosis. For some people, however, the condition quickly progresses to hallux rigidus, with full-blown osteoarthritis and bone spurs greatly limiting motion. In this population, the windlass mechanism begins to fail, and the big toe becomes locked in a nonfunctional hallux rigidus position.

Referring to big-toe restrictions, my mentor Philip Greenman, DO, stated: “If discovered at an early stage with minimal spurring and the ability to engage the windlass mechanism, I believe manual therapy and a specialized corrective exercise program can maintain that mobility and prevent progression of the deformity. By systematically increasing dorsiflexion at the first metatarsal joint, inflammation and protective muscle guarding may be reduced, leading to symptomatic improvement.”2

Assess and Treat

I’ve found the simple “grind test” very helpful in assessing for hallux limitus and rigidus. If the therapist is able to extend the client’s toe but pain or a crunchy noise is reported as the first MTP joint is compressed, hallux limitus may be suspected. Conversely, if pain or grinding is reported and the joint resists extension (even at mid-range), advanced hallux rigidus osteoarthritis could be the culprit.

Once I’ve identified a painful or immobile MTP joint, I begin to address it by performing graded exposure stretches to all lower leg, ankle, and foot musculature to increase flexibility and decrease reactive spasm. Next, I perform the following three myoskeletal mobilization techniques: long axis extension-rotation, dorsal and plantar glide, and abduction-adduction (Images 4–6).

Summary

Limited first-toe extension leads to altered mobility at the talocrural joint. If the ankle can’t dorsiflex properly, the knee and hip will not fully extend. The result is decreased hip flexor flexibility and repeated extension-rotation of the lumbar spine. This is a prime example of how a kink in a lower extremity can affect structures further up the kinetic chain.

Myoskeletal therapy employs low-force stretching maneuvers to reduce symptoms and improve MTP joint function. We are encouraging the body to move rather than forcing it to do so, as forcing movement causes the brain to layer the area with protective muscle guarding. Along with manual treatments to improve MTP mobility, it’s essential to assign self-care exercises to help maintain the gains and further increase first-toe range of motion. Clients spend the majority of their time outside the clinic, so they must share responsibility for locking in the changes.

I’ve found clients are more likely to perform playful exercises, such as bouncing on a mini trampoline, hiking, and ankle rocking. The act of rocking in all directions with the feet dorsiflexed is one of the best and easiest ways to fully restore function of the feet, ankles, knees, and hips synchronously—the way they’re designed to work. Give these assessment and treatment options a try in your own practice to help clients who present with stiff and painful hallux limitus and rigidus.

Notes

1. Bryant Ho and Judith Baumhauer, “Hallux Rigidus,” EFORT Open Reviews 2, no. 1 (January 2017): 13–20, https://doi.org/10.1302/2058-5241.2.160031.
2. Philip Greenman, “Exercise as An Adjunct to Manual Therapy” (class notes, Michigan State College of Osteopathic Medicine, 1992).

Images

<Image 1>Arthritic and movement-challenged MTP joint.

<Image 2>Anatomy of the windlass mechanism.

<Image 3>Hallux valgus and inflamed bunion.

<Image 4>The therapist’s right hand braces the distal metatarsal bone while the finger and thumb slowly distract, extend, and rotate the client’s proximal phalanx bone.

<Image 5>The therapist’s right hand braces the distal metatarsal bone while the finger and thumb glide the MTP joint up and down (dorsal and plantar glide).

<Image 6>The therapist’s right hand braces the distal metatarsal bone while the finger and thumb abduct and adduct the client’s proximal phalanx bone (joint translation).