A number of interrelated factors, including muscular overuse, knee injuries, joint disorders and back injuries, may trigger pain and soreness in the upper, outer portion of one or both of your thighs.
Before you attempt to alleviate sore outer thigh muscles, ask a doctor to diagnose the source of the pain.
Overusing Your Muscles
Despite evidence to the contrary, the myth of spot reduction exercise still prevails. If you tend toward outer thigh fat accumulation, which is common among women, performing 100 repetitions on the outer thigh machine, or performing hundreds of side leg raises, will not reduce the fat content in your legs.
The burning sensation in your sore outer thigh muscles results from overuse, not the fat-burning process. If you perform more exercises for your outer thighs than you do for your inner thighs, you could trigger a muscular imbalance, which, in turn, may distort your movement mechanics and lead to postural misalignment and chronic pain.
Read more: How to Relieve Tired Muscles
Thigh Pain Causes
Bursitis is inflammation of the fluid-filled sacs that sit at the upper outer portion of your thigh bone. These sacs, called bursae, cushion the spaces between muscles, tendons, and bones of your hips and thighs.
Irritation of these bursae cause inflammation and pain, which may start in your hip and radiate down the outer portion of your thigh. The pain makes it difficult to climb stairs or sleep on the affected side. Abnormal walking and standing patterns may cause bursitis.
Is It Meralgia Paresthetica?
Tingling, numbness and burning sensations in one of your outer thighs characterizes a condition called meralgia paresthetica. Compression of the nerve that supplies sensation to your outer thigh causes this condition. Common causes of meralgia paresthetica include weight gain, pregnancy and wearing overly tight clothing, says Mayo Clinic.
Using a heavy tool belt or wearing a tight girdle makes you more susceptible to this condition, warns the American Academy of Orthopaedic Surgeons. Treatment usually involves removing the cause of the compression. Your doctor may recommend weight loss, wearing looser clothing or using a tool box in lieu of a tool belt.
Iliotibial Band Syndrome
Your iliotibial band, called the IT band, runs down the outer part of your thigh, and takes responsibility for pelvic stability. Excessive running or hill climbing may trigger a condition called iliotibial band syndrome.
Cedars-Sinai says that researchers are still not sure of the exact cause of iliotibial band syndrome, but what they do know is that friction from the IT band rubbing against the lower edge of the thigh bone accounts for the pain. The pain often begins in the lateral side of your knee, when your IT band pulls against your outer knee, inflaming the bursa sac located in your knee and causing the sides of your thighs to hurt.
The pain may start in your outer knee and radiate upward along your entire outer thigh. Lying sideways on a foam roller and gently rolling back and forth help address the source of the pain. Adjusting your training schedule should prevent its recurrence.