Injuries that can cause calf muscle cramps and foot numbness while running include chronic exertional compartment syndrome and deep vein thrombosis. Poor conditioning, obesity and muscle tightness can increase your risk of experiencing an injury along with muscle cramps and foot numbness. The first line of treatment may include rest, calf stretches and ice. Consult your physician for further treatment options because these symptoms may indicate a serious underlying condition.
When you experience a cramp, or an uncontrollable contraction, in your calf muscles, it can compress the blood vessels and nerves running through your calf. The decreased blood flow and irritation to your nerves may result in foot numbness or tingling. Muscle fatigue, dehydration, low sodium and heat exhaustion can all lead to muscle cramps in your calf. Hot and humid weather conditions, shoes with inadequate arch support and poor running mechanics such as overstriding can increase your risk of experiencing muscle cramps and foot numbness as well.
A thin layer of tissue surrounds your calf muscles, creating a compartment. When swelling and pressure build up within this compartment, it is called chronic exertional compartment syndrome, or CECS. According to a 2010 "Current Review of Musculoskeletal Medicine" article, runners are susceptible to CECS, especially if they overpronate or run flatfooted. The pressure and swelling around your muscles lead to pain, tightness and weakness that may mimic that of a muscle cramp. The pressure also decreases blood flow and compresses nerves, causing numbness and tingling from your calf to your foot.
Calf muscle cramps and foot numbness may also be the symptoms of ankle impingement syndrome, a herniated disk in your low back or deep vein thrombosis, or DVT. Ankle impingement syndrome is when nerves and tendons around your ankle become pinched. This can lead to foot numbness and cause you to limp or alter your running mechanics, which may eventually lead to muscle cramps. A herniated disk in your low back can cause referred pain and muscle dysfunction in your calf and foot, including numbness and muscle cramps. DVT is a blood clot that can occur in your leg, reducing blood flow. Symptoms include muscle cramps, pain, swelling and possibly numbness.
First, immediately stop running to avoid further discomfort and damage. With CECS, your symptoms should dissipate relatively quickly following rest. For muscle cramps, lightly massage or stretch your calf muscles, move into a cooler location, ice your calf and drink sports beverages to rehydrate. Consult your physician immediately if you have a herniated disk or a DVT. Additional treatments include corticosteroid injections, orthotics, physical therapy and surgery.