ANATOMY
In human anatomy, the calf presents the posterior part of the lower leg. It comprises two muscles: the larger gastrocnemius and the smaller soleus muscle, located beneath the gastrocnemius. These two calf muscles taper and merge at the calf base, and the tough connective tissue of the calf merges with the Achilles tendon at the bottom of the calf.
The calf muscles are of crucial importance for movement – walking, running, or jumping. During these activities, the calf muscles pull the heel up in order to allow forward movements.
SYMPTOMS AND CAUSES
Calf muscles can become painful and dysfunctional due to many reasons, including muscle strain, pulled muscle, muscle tear, muscle rupture, myositis, rhabdomyolysis, and cancer. Although sometimes underestimated, a common cause of calf pain is the calf trigger points.
Although the lower leg muscles are pretty strong, they can become overloaded. Calf trigger points can get activated because of some type of stress or overload on the calf muscles. For example, ankle sprains and fractures most commonly overload the lower leg muscles leading to trigger point development. The calf trigger points arising after a such injury usually persist for some period of time after the ankle has recovered. In that case, the patient may feel intermittent pain and general weakness.
However, calf trigger points can become activated by other types of stress on the muscles. Even everyday activities can overload the muscles of the calf region. Moreover, women wearing high heels can activate calf trigger points, as the foot position and mechanics of the foot and ankle present overload calf muscles.
Moreover, physical stress or emotional or psychological tension may activate the trigger points.
Sometimes the pain on other sites may be misdiagnosed and attributed to other diagnoses, while it is actually caused by the calf trigger points.
Many people suffer from pain in the arch of the foot. Most frequently, it is diagnosed as plantar fasciitis without any second thoughts. However, the calf trigger points can produce such type of pain, in addition to the trigger points of the foot muscles.
Furthermore, heel pain is caused mainly by the calf trigger points. Although heel pain is commonly attributed to heel spur, the bone spurs itself does not usually produce pain. But the truth is that most heel spurs develop due to chronic calf trigger points.
CALF TRIGGER POINT MUSCLES
So, which muscles contain these trigger points?
These muscles are:
- Gastrocnemius muscle
- Soleus muscle
- Peroneus muscle
- Tibialis anterior muscle
GASTROCNEMIUS TRIGGER POINTS
The gastrocnemius muscle is the larger calf muscle, and the trigger points in this muscle may cause calf pain and cramps, but also foot pain. Due to its anatomical characteristics and relationship with the Achilles tendon, gastrocnemius trigger points can cause pain on the sole (bottom of the foot), commonly being misdiagnosed as plantar fasciitis.
The cramps caused by these trigger points typically occur at night.
Patients can also complain of pain in the posterior of the knee and difficulty walking uphill and upstairs.
SOLEUS TRIGGER POINTS
The soleus is the muscle lying beneath the gastrocnemius muscle. Soleus trigger points usually cause pain in the posterior of the lower leg and in the Achilles tendon. The pain is often extending down the calf to the heel.
The Achilles tendon may become tender, especially after jogging or running. As it may become overloaded by the body weight during the day, it is not uncommon that it aches at night. Furthermore, calf swelling can develop as a result of soleus trigger points.
Interestingly, calf trigger point pain is usually referred to as feet to get a person “off their feet” and allow rest and muscle recovery.
PERONEUS TRIGGER POINTS
Peroneus trigger points usually cause ankle pain but also weakness and instability. Because of its complex anatomy, patients with active peroneus trigger points can complain of the tenderness and pain of the ankle and the inability to lift their feet properly during walking.
History of ankle sprains or fractures is also a common complaint in patients with active peroneus trigger points.
TIBIALIS ANTERIOR TRIGGER POINTS
Tibialis anterior trigger points can cause the top of the foot and ankle pain. Furthermore, the pain may refer to the big toe. The main action of the tibialis anterior muscle is to lift the foot and stabilize it during walking. Therefore, the patients may also complain of difficulty walking.
Active tibialis anterior trigger points can often be misdiagnosed with foot drop or foot slap.
TREATMENT
Calf trigger points can be treated by professional massage, self-massage and trigger point therapy. Trigger point therapy implicates applying direct pressure to these spots, which interrupts circulation to the tissues. Interrupted circulation causes a nitric oxide build-up, which signals the micro capillaries to open. In this way, blood flow to the tissue is improved, and the muscle knot breaks up.
These treatment options have been shown to provide pain relief but also have benefits in increasing mobility and flexibility, improving balance, reducing pain and muscle cramps, as well as post-exercise soreness. o
So, when experiencing pain in the calf, ankle, or foot, calf trigger points should always be carefully assessed and treated accordingly.
MD, PhD. Physical Medicine & Rehabilitation Physician from São Paulo - Brazil. Pain Fellowship in University of São Paulo.