Aerobic exercises like jumping jacks, step aerobics or side-to-side steps can place stress on the balls of the feet as you land on these first to prevent knee muscle strain. While the balls of your feet contain protective tissue to support impact, an aerobics session may place too great a strain, resulting in symptoms like foot numbness. Although this condition is not typically cause for concern, taking preventive measures and seeing a physician if discomfort worsens can help resolve foot numbness issues.
Fascia Pain and Pressure
During an aerobics session, you are varying the pressures on the foot through transitioning to different exercises that place demands on the ball of your foot. While this area has a tough, protective band that extends to the heel known as the fascia. This band surrounds the muscles in the foot. These muscles can expand as much as 20 percent during your exercise routine, according to Running Times. Although the muscles may enlarge, the fascia may not enlarge with them. This causes the fascia to put pressure on the blood vessels and nerves on the foot, which can result in pain. If your feet appear slightly swollen or pain subsides when you rest or elevate your feet after an aerobics session, fascia swelling could be the cause.
Artery Compression
The back of your knee also is known as the popliteal region, named for the artery that runs to your foot. When you perform an aerobics session, particularly one that places extra demands on the calf muscles through jumping and/or calf raises, the calf muscles can compress the popliteal artery. The result can be impeded blood flow to your foot. If you stop performing aerobic activities and sensation returns to the foot, pressure on the popliteal artery can be to blame. While this condition is not necessarily cause for concern, chronic swelling in the artery can affect your circulation and lead to nerve tissue damage. In this severe instance, surgery to restore blood flow to the artery may be necessary.
Neurologic Causes
If your aerobics session is particularly high-impact, the numbness in the balls of your feet may be simply due to repeated trauma to the nerve endings in the foot. Just like your legs or buttocks can go "to sleep" from the pressure of sitting too long, you feet can experience a similar effect during an aerobics session. However, sometimes tingling in the foot can be related to a nerve condition in another part of the body, such as sciatica in the lower back, in which a slipped or ruptured disc presses on the sciatic nerve and causes tingling and numbness in the nerves. If lower back pain and pressure accompanies your foot numbness or the tingling reappears when you are not exercising, this can be an indicator that a condition like sciatica is to blame.
Physician Evaluation
If numbness in the balls of your feet is affecting your ability to exercise, seeking a physician's evaluation can help you learn more about what is causing your problems to occur. In addition to a physical examination, your physician may recommend imaging scans or exercise testing to evaluate your blood vessels and nerves before and after exercise. If the numbness turns into pain, cease exercising and seek medical attention to rule out a more serious condition, such as a blood clot in the leg.
References
- MedlinePlus: Numbness and Tingling
- Running Times: Ask the Coaches: Tingling and Numbness in Feet
- Spine-Health; Leg Pain and Numbness: What Might These Symptoms Mean?; Dr. Grant Cooper; July 2010
- Gaiam Life: Restorative Exercise for Foot Pain
- Sports Injury Clinic: Foot Injuries, Toe Pain and Heel Pain
