The lower limb is the area from the hip to the tip of the toes – pelvis, hip joints, buttocks, thighs, knees, lower legs, ankles, feet and toes . It is mainly composed of muscle and bone with a network of blood vessels, lymphatics and nerves supplying the area. The lower limbs bear most of the body weight with the feet carrying all of this weight and distributing the force to the ground. The force is multiplied with walking and even running and it is fair to say that with regards to mobility and weight bearing functions, it is the lower limbs that are the hardest working parts of the body especially in an active person. Soreness is therefore common and often associated with strain and overuse of the muscles.
Meaning of sore feet
Sore feet is any discomfort, ache or pain in the ankles, top of the foot, soles and/or the toes. It is more common after a period of long walking, running or other physical activity leading to overuse of the lower limbs. This may vary from person to person where a fit person is able to tolerate greater exertion. In most of these cases, the pain is muscular and may sometimes involve the muscle tendons and ligaments. However, discomfort or pain in the feet and legs may also arise from the overlying skin and subcutaneous tissue, blood vessels (arteries and veins), lymphatics (lymph nodes and vessels), nerves and bones.
There are several common mechanisms by which one would experience pain in the feet. It is often difficult to isolate the exact cause, structure that is affected or mechanism that is causing the pain or discomfort without taking other symptoms into consideration.
- Skin, subcutaneous fat or connective tissue –impetigo, cellulitis or fasciitis.
- Arteries – peripheral arterial disease (PAD).
- Veins – vascular insufficiency, varicose veins or deep vein thrombosis.
- Nerves – neuropathy, neuritis or nerve root compression.
- Joint lining or joint cartilage – arthritis or arthrosis.
- Muscles and tendons – strain, tendinitis.
- Ligaments – sprain.
- Lymph nodes or lymphatic vessels – lymphadenitis or lymphangitis.
- Bone – osteitis, osteomyelitis, osteoporosis or fractures.
Sore Feet Causes
Some of the common causes of generalized foot soreness includes :
- Bruises arise with injury to the foot. It can affect the outer lying parts like the skin, subcutaneous tissue or even the muscles but may sometimes extend deeper to the bone. It may arise from overexertion of the legs and feet, banging into a hard object, dropping a heavy object on the foot or pressure from tight shoes or high heels. There are several other causes of foot injury which may lead to bruising.
- Muscle strain associated with overuse like standing for long periods or walking and running for long distances often causes generalized soreness through most of the feet. The tendons may also be involved thereby leading to tendinitis. Although any tendon can be involved, the large Achilles tendon is commonly affected.
- Peripheral arterial disease (PAD) is the narrowing of the arteries supplying the legs and feet. There is less oxygenated blood supplying the feet leading to pain particularly during activity when the oxygen demands are greater. If a blood clot occludes the the already narrowed artery then there may be severe injury to the tissue of the feet. This is known as ischemia.
- Nerve problems may be associated with compression of the nerve roots as it emerges from the spine (pinched nerve), inflammation of the nerve (neuritis) with injury or damage of the nerve as is commonly seen in diseases like diabetes mellitus (diabetic neuropathy).
- Bone problems may arise when there is injury of the bone, fractures or bone spurs. Stress fractures of the feet are not uncommon in a very active person where tiny cracks form in the bones from high impact activities. Bony spurs are outgrowths of bone tissue that can arise from any bone. In the feet, it more commonly arises from the calcaneus and is known as a heel spur.
- Calluses are thickening of the skin on the feet, usually on the areas exposed to pressure like the soles with prolonged standing or walking, or the sides of the feet and toes with wearing tight shoes. Calluses on the top of the toes are known as corns.
Soreness of certain areas of the feet may be due to more specific causes.
- Gout is an inflammatory condition of the small joints due to an accumulation of urate crystals. It is a form of arthritis although other types of arthritis may also affect the toe joints.
- Hammer toe is a toe joint deformity causing it to be permanently bent, curling downwards in a claw-like orientation. A similar condition is mallet toe affecting the upper toe joint whereas hammer toe affects the middle joint.
- Bunion is a bump at the base of the toe which can become inflamed. It arises with wearing tight shoes that pushes the big toe against the other toes.
Common causes of soreness on the soles of the feet, which may involve the ball of the feet and heels, includes :
- Plantar warts are growths on the soles of the feet due to the presence of the human papilloma virus (HPV). It tends to arise on areas of the skin which have been injured like with cuts or where calluses have formed.
- Plantar fasciitis is the inflammation of the connective tissue sheath that lines the bottom of the feet from the toes to the heel. The inflammation is often a result of stretching or tearing of the fascia.
- Flat feet is where the normal arches of the feet are absent when standing. This arch is formed by the firm pulling of the muscle tendons of the feet. It becomes loose with age or injury.
Picture from Wikimedia Commons
The heel may be affected by the same conditions that can occur on the entire sole, particularly plantar fasciitis and warts. Another common cause of heel pain is using high-heeled shoes which causes muscle strain, tendinitis and bruising of the bone and soft tissue of the heel.
- Calcaneal spur is a bony outgrowth on the large foot bone, the calcaneus, that makes up the heel of the foot. It may arise with prolonged and severe impact on the heel associated with running, certain sports and may also occur in overweight or obese individuals.
- Bursitis is inflammation of the small fluid filled pads that reduce friction and thereby help with movement at different parts of the body where the bone and tendons may rub against each other. It may become inflamed with prolonged overuse or in arthritis.
- Achille’s tendinitis is inflammation of the thick band of tendons felt at the back of the foot. This tendon connects the calf muscles to the heel. It may become strained with overuse of the calf muscles like running, walking up stairs or up an incline for long periods, inappropriate footwear during physical activity, flat feet and trauma to the calf muscles or tendon.
Sore Ball of Foot
The ball of the foot may be affected by the conditions that afflict the toes and sole of the foot. Conditions that may cause soreness on the balls of the feet includes :
- Morton’s neuroma is a thickening of the nerve tissue between the toes most commonly occurring between the third and fourth toes. It often occurs with wearing tight footwear and high-heeled shoes.
- Metatarsalgia is inflammation of the foot bones (metatarsals), particularly at the head of the these bones. It is associated with prolonged walking, running, wearing tight shoes, bunions, hammertoe, obesity, Morton’s neuroma and stress fractures.
Sore Top of Foot
The top of the foot, or dorsal surface, does not bear weight as is the case with the toes, ball of the foot, sole and heel. Nevertheless it may be affected with conditions that arise in these areas thereby leading to soreness. Tight fitting shoes, dropping objects on the feet, poor circulation to the feet particularly if the dorsalis pedis artery is affected, and dorsal midfoot interosseus compression syndrome (DICS) may cause soreness on the top of the foot.