Rising from a squatting position or stepping onto a chair tests proximal leg strength; walking on the heels and on tiptoe tests distal strength. Pushing with the arms to get out of a chair indicates quadriceps weakness. Swinging the body to move the arms indicates shoulder girdle weakness.
Physicians must distinguish true muscle weakness from subjective fatigue or pain-related motor impairment with normal motor strength. This requires a history and physical examination, which guide laboratory testing, imaging, electrodiagnostic testing, and muscle biopsy.
Strength testing often involves your doctor asking you to move in a certain way while the doctor applies resistance to your movement. For a leg or hip condition, for example, you may be asked to sit on a table and extend your knees open, pressing as hard as you can while the doctor presses back against the movement.
An EMG measures the response of muscles to electrical activity and how much electrical activity a muscle contraction produces. Your healthcare provider may recommend an EMG if you have symptoms such as muscle weakness or numbness and tingling.
Muscle weakness in the legs may indicate a neuromuscular disease is present. These diseases lead to a loss of functioning in nerves and muscles throughout the body. They include muscular dystrophy, amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), myasthenia gravis and fibromyalgia.
Leg weakness can be caused by a variety of medical conditions, some of which are serious. Possible causes include stroke, systemic diseases, inflammatory conditions, nerve damage, muscle disorders, and medication side effects.
Sudden weakness in the legs may be a sign of a medical emergency such as stroke or cauda equina syndrome and any sudden or unexplained leg weakness should warrant immediate medical attention.
A blood test will let your doctor know if you have elevated levels of muscle enzymes, which can indicate muscle damage. A blood test can also detect specific autoantibodies associated with different symptoms of polymyositis, which can help in determining the best medication and treatment.
Doctors use a blood test to look for elevated levels of a substance called creatine kinase, which is released into the bloodstream when muscle fibers deteriorate. Elevated levels may mean you have an inflammatory myopathy.
Symptoms of muscle weakness include difficulty rising from a chair, brushing your hair, lifting an object off a high shelf, or dropping things. It might cause drooping of an eyelid or difficulty smiling, depending on which muscles are weak.
Drop Jump — a test of leg strength and power which requires the athlete to drop off a box and immediately jump as high as they can. Also see the Incremental Drop Jump, used for measuring the Reactive Strength Index. Standing Long (Broad) Jump Test — jump off two legs for maximal distance, a measure of leg power.
Medical Imaging Tests for Leg Pain
MRI Scan of the Spine, Computerized Tomography (CT) Scan, ultrasound, or plain x-rays are typically used while diagnosing leg pain. Imaging tests help identify herniated discs, abnormal bone growths (bone spurs), bone fractures, and tumors among others.
Muscle weakness is commonly due to lack of exercise, ageing, muscle injury or pregnancy. It can also occur with long-term conditions such as diabetes or heart disease. There are many other possible causes, which include stroke, multiple sclerosis, depression, fibromyalgia and chronic fatigue syndrome (ME).
The weakness can make your legs feel heavy, as if they are being weighed down by something. They may also ache and hurt. Some people with MS describe it as like having bags of sand attached to their legs. This muscle weakness combined with MS fatigue can be upsetting.
MRI scan – a test that uses a strong magnetic field and radio waves to produce detailed pictures of the inside of your body. This can help to identify the affected muscles and will also show the extent of any muscle damage.
Even if you can identify a cause, you still might need to see a doctor if you aren't getting better. “If you have muscle weakness or fatigue that persists for more than two weeks, it can be something else going on in your system,” Scott said. Another red flag is if healthy changes don't bring relief.
A nerve conduction velocity (NCV) test — also called a nerve conduction study (NCS) — measures how fast an electrical impulse moves through your nerve. NCV can identify nerve damage.
Vitamin D helps your body use calcium. But when you're deficient in this vitamin, your legs may feel weak, sore and heavy. A vitamin E deficiency may be another reason your legs feel heavy after a run.
Is there a loss of muscle strength, or is the problem a vague loss of energy, weariness, or lassitude? True weakness usually indicates a medical disorder. Fatigue, in contrast, may result from medical, psychiatric, or physiologic causes. Other symptoms should not be confused with weakness.
Summary. Weakness in the legs is a common symptom of many health conditions and injuries, including autoimmune diseases, spinal conditions and injuries, and stroke. Often, leg weakness will resolve over time, but in some cases, it can be a medical emergency, especially if the weakness comes on suddenly.
As a result, people with heart failure often feel weak (especially in their arms and legs), tired and have difficulty performing ordinary activities such as walking, climbing stairs or carrying groceries.