Muscle Weakness: Causes, Symptoms and Supplements

Muscle weakness can result from various factors, such as poor movements or inadequate physical activity. To address muscle weakness, consider taking supplements. This guide is designed to help you understand muscle weakness by explaining its definition, causes, and symptoms, and recommending supplements that can help reduce or alleviate these symptoms.

What Is Muscle Weakness?

Muscle weakness occurs when normal muscle contractions or movements cannot be produced despite one's best efforts. It is also known as weak muscles, diminished muscle strength, or muscular weakness.

Generally, the brain sends impulses to the muscles through the spinal cord and nerves, causing voluntary muscle contractions. However, accidents or illnesses affecting the brain, neurological system, muscles, or their connections can disrupt this process, leading to abnormal muscle contractions and eventual muscle weakness.

What Causes Muscle Weakness?

Muscle weakness can result from various factors, including infections, traumas, electrolyte imbalances, neuromuscular disorders, autoimmune diseases, and other systemic inflammatory ailments. 

Sarcopenia

As age increases muscle mass and strength decrease. This causes muscle weakness. It mainly affects the elderly population and reduces the quality of life as one cannot do daily tasks. It affects the musculoskeletal system and is responsible for falls, and fractures. A decrease in the number and size of muscle fibres makes the muscle thin and weak. The body undergoes certain changes while developing sarcopenia. Hormones like testosterone and insulin-like growth factors affect the muscle fibres leading to sarcopenia.

The causes of sarcopenia are physical inactivity, obesity, insulin resistance, malnutrition, rheumatoid arthritis, and chronic diseases like diabetes, cancer, HIV, etc., It can be treated by making healthy food choices, maintaining an active lifestyle, and taking medications.

Cellular Senescence

As we age the senescent cells or zombie cells in our body accumulate at one point or in one tissue which leads to diseases such as cancer, muscle disorders etc., The accumulation of these cells also leads to the inflammation of muscles leading to myositis. Senolytics are compounds that target the pathways and induce apoptosis in activated zombie cells. These cells produce harmful compounds such as senescence-associated secretory phenotype (SASP) which produce high levels of inflammatory cytokines, immune modulators, growth factors, and proteases.

Autoimmune, Neuromuscular, and Neurological Diseases

• Amyotrophic lateral sclerosis (ALS): A progressive neurological disorder affecting motor neurons, resulting in weakened muscles and loss of voluntary functions.
• Bell’s palsy: Sudden facial muscle weakness caused by damage to the 7th cranial nerve, often temporary with recovery spans 2 weeks to 6 months. Though no cure exists, most regain full facial strength.
• Cerebral palsy: Developmental brain damage affecting movement and posture, leading to varied motor function issues like floppy limbs, spasticity, irregular posture, uncontrolled movements, and an unstable walk, defining the condition's impact on motor function.
• Graves’ disease: Immune system disorder causing excessive thyroid hormone production, impacting muscle function. While it can affect anyone, it's more prevalent in women and those under 40. Treatment focuses on reducing hormone levels to alleviate symptoms and combat associated muscle weakness.
• Multiple sclerosis (MS): Chronic autoimmune disease affecting the central nervous system, leading to muscle weakness. It occurs when the immune system mistakenly attacks myelin, the protective tissue around nerve fibres, disrupting communication between the brain and the body. This impairment in nerve function results in muscle weakness.
• Muscular dystrophies: Genetic mutations causing progressive muscle weakness. Different types affect specific muscle groups, showcasing varied symptoms at different ages. It can be familial or spontaneous, with individuals of the same type displaying diverse symptoms due to genetic variations.

Electrolyte Imbalances

Electrolytes are crucial for the proper functioning of the heart, brain, muscles, and nerves. Muscle weakness can arise from imbalances in electrolyte levels, including calcium, potassium, sodium, and magnesium. Specific electrolyte disorders, such as hyperkalemic (High blood potassium levels) periodic paralysis, and hypokalemia (low blood potassium levels), can contribute to this. Imbalances are triggered by various risk factors, including fluid loss from vomiting, diarrhoea, or sweating. Other contributing factors encompass chemotherapy, inadequate dietary habits, and the use of immunosuppressive drugs or antibiotics.

Thyroid Disorders

Hypothyroid myopathy is a muscle disease caused by insufficient thyroid hormone production by the thyroid gland. The symptoms include muscle weakness, fatigue, and other manifestations resulting from the body's metabolism, which is impacted by low thyroid hormone levels. This condition is seen in hypothyroid patients with muscle pain and weakness in cognition, and it is also observed in acquired cases.

Viruses and Infections

Some viral infections can result in muscle weakness, including:

• Botulism: Botulism is a rare yet severe illness caused by a toxin commonly found in contaminated food. Initial symptoms include muscle weakness in the eyes, mouth, throat, and face, leading to droopy eyelids, impaired vision, slurred speech, and difficulty swallowing.
• Influenza: Influenza, commonly known as the flu virus, can lead to myositis—an inflammation of muscles resulting in weakness, pain, and difficulty walking. This condition is often associated with flu infections.
• Meningitis: Meningitis involves inflammation of the meninges surrounding the brain and spinal cord and can be caused by bacteria, viruses, fungi, or parasites. Complications may include loss of sensation, memory impairment, muscle weakness, paralysis, and seizures.
• Human Immunodeficiency Virus (HIV): HIV actively targets and weakens the immune system, potentially leading to myopathies characterised by a gradual and symmetrical decline in muscle strength.

Rare Causes of Muscle Weakness

A doctor may explore uncommon causes when diagnosing muscle weakness if it is not caused by any of the previously listed conditions or if the patient has specific risk factors.

Condition	Description
Dermatomyositis	An inflammatory condition affecting muscles that leads to weakness, pain, and tightness.
Polymyositis	Typically results in weakness in muscles surrounding the body's trunk, including the neck, shoulders, hips, and thighs.
Rheumatoid Arthritis	An inflammatory, long-term autoimmune disease targeting the joint lining. Commonly affects hands and feet.
Sarcoidosis	An inflammatory disease that typically affects lymph glands and lungs, resulting in inflamed masses of tissue.
Secondary Hyperparathyroidism	Frequently results in joint and bone discomfort in the lower limbs.
Becker Muscular Dystrophy	Hereditary condition cause rapid, increasing muscle weakening, typically affecting males and younger individuals.
Systemic Lupus Erythematosus	Often referred to as lupus, this illness can impact joints, the brain, the heart, the lungs, and other body parts. Muscle weakness is a common sign during a lupus flare-up.

 

Symptoms of Muscle weakness

The symptoms of muscle weakness include:

• Abnormal Reflexes An involuntary action produced in response to a stimulus is called an abnormal reflex. A lesion in the motor pathway, nerve compression, or a neurological condition causes it.
• Balance Problems- The person cannot balance their centre of gravity and posture. 
• Cramps- Involuntary contraction of a muscle lasts from seconds to minutes. It causes severe pain.
• Deformity- This occurs due to pain, discomfort, and restriction of movement. It is caused due to arthritis, amputation, sarcoma removal, neurological conditions etc., 
• Inflammation- The body uses inflammation as a natural healing process, which can result in swelling and heat that lasts for several weeks. Pain and a restricted range of motion may result from this swelling and heat.
• Falls- These occur in people above 65+ years as their bones degenerate and the risk of fractures increases. Certain factors like environment, clothing, and poor balance will lead to falls.
• Fatigue-Feeling of extreme tiredness and abnormal functioning in normal levels. It can be either mental or physical. Less physical activity leads to reduced mobility and reduced mobility causes muscle weakness.
• Immobility- Here an individual cannot move and some movement also causes pain because the muscles are weak. This may lead to cardiovascular diseases. 
• Numbness-Suddenly the foot or hands of an individual become numb due to nerve irritation, stroke, diabetes, hyperventilation, nerve entrapment, and neurological conditions. 
• Movement Disorders- Any abnormality in movement is referred to as a movement disorder. Either a musculoskeletal injury or issue or a neurological illness could be the cause of this. Movement disorders can arise from a variety of causes, including acute traumatic injuries that result in structural damage such as fractures or contusions, as well as overuse or repetitive sprains.
• Pain- Abnormalities in the sympathetic nervous system, damage in the peripheral nerve, falls, fractures, etc., make the muscle weak and cause pain.
• Tingling / Pins & Needles-This condition is known as paresthesia. It occurs for a short period when the blood supply to a nerve is cut off and reduced. It results in swelling and inflammation of the muscles. 

Diagnosis and Treatment for Muscle Weakness

Diagnosis involves a medical history, physical exam, and tests. Treatments address underlying causes, including physical therapy, occupational therapy, supplements (SeneVit, Ca-AKG, and NMN), dietary changes, and surgical intervention.

Physical Therapy

A physical therapist can help strengthen weak muscles, restore muscle imbalances, and improve muscle movement. One gets the ability to complete their daily activities which were challenging due to muscle weakness like climbing stairs, standing up from a chair, walking, etc., Individuals with autoimmune, neuromuscular, and neurological diseases should go for physical therapy. Therapies like acupuncture, hydrotherapy, massage, electrotherapy etc., are examples of physical therapy.

Occupational Therapy

Children, adults, or elderly people who cannot meet their daily needs due to muscle issues should go for occupational therapy. This therapy strengthens muscles, increases muscle tone, and enhances muscle endurance. The therapist assists you with various stretching techniques and heat therapy which help in loosening the tight and stiff muscles. Mainly posture and joint mobility are improved.

Supplements

SeneVit, Ca-AKG, and NMN show promise in reducing muscle weakness and improving muscle health through anti-inflammatory, antioxidant, and endurance-promoting properties.

SeneVit- Senolytics are compounds that target the pathways and induce apoptosis in activated zombie cells. These cells produce harmful compounds such as senescence-associated secretory phenotype (SASP) which produce high levels of inflammatory cytokines, immune modulators, growth factors, and proteases. Fisetin in SeneVit is a senolytic activator that helps in eliminating the senescent cells. It also improves the proliferation and function of myogenic progenitor cells. It also induces apoptosis and reduces oxidative stress.

Ca-AKG, a metabolite generated during endurance exercise, effectively reduces muscle weakness by inhibiting corticosterone-induced protein degradation. It rescues muscle atrophy in a muscular dystrophy mouse model by suppressing proline hydroxylase 3 (PHD3) and enhancing β2 adrenergic receptor (ADRB2) stability, revealing a mechanism for AKG's protective effects against muscle wasting and protein degradation (Cai et al., 2017).

NMN- Nicotinamide Mononucleotide helps in reducing muscle weakness and improves muscle endurance. NMN, a precursor to NAD+, supports muscle health by enhancing mitochondrial and muscle stem cell function. NAD+ repletion, facilitated by NMN, ameliorates muscular dystrophy, extending lifespan in mice. NMN's role in energy metabolism and its antioxidant properties contribute to improved skeletal muscle pathophysiology, offering the potential to reduce muscle weakness, especially during ageing and associated metabolic diseases (Wagner et al., 2022).

Dietary Changes

Eating protein and nutrient-rich foods, maintaining fluid intake, and balanced nutrition contribute to overall muscle health.

Surgical Intervention

Addresses underlying anatomical issues, such as nerve compression or structural defects, to enhance musculoskeletal performance. Procedures like decompression surgeries or repairs to injured tissues aim to alleviate nerve pressure, enhance muscle stability, and restore proper function, ultimately promoting improved strength and overall musculoskeletal performance.

Conclusion

Addressing muscle weakness requires a comprehensive approach, considering various causes. Therapies, medications, lifestyle adjustments, and supplements play key roles, along with dietary changes and surgical interventions, in promoting muscle health and mitigating weakness.

 

FAQs

1) What is the reason for muscle weakness?

Muscle weakness may stem from various causes, including nerve damage, nutritional deficiencies, overexertion, diseases, or medical conditions affecting muscle function.

2) How do you strengthen weak muscles?

Strengthen weak muscles through targeted exercises, resistance training, and gradual progression under professional guidance for improved muscle tone and function.

3) Which deficiency causes muscle weakness?

Vitamin D deficiency can lead to muscle weakness due to its crucial role in maintaining muscle function and overall health.

4) What are the signs of muscle weakness?

Fatigue, difficulty lifting or holding objects, unexplained falls, reduced grip strength, and limited endurance are indicative signs of muscle weakness.

5) What vitamins are good for muscle weakness?

Vitamins D, B-complex (especially B12), and E are beneficial for muscle weakness, promoting strength, repair, and nerve function.

6) Which food is good for muscle weakness?

Protein-rich foods like lean meats, fish, eggs, and legumes, along with fruits and vegetables, aid muscle strength and recovery.

 

References

Lin, W., Zhao, Y., Liu, C., Yan, Y., & Ou, Q. (2022). Quercetin supplementation and muscular atrophy in animal models: A systematic review and meta-analysis. International Journal of Food Properties, 25(1), 2166-2183.

https://doi.org/10.1080/10942912.2022.2127764 

Cai, X., Yuan, Y., Liao, Z., Xing, K., Zhu, C., Xu, Y., ... & Shu, G. (2018). α-Ketoglutarate prevents skeletal muscle protein degradation and muscle atrophy through PHD3/ADRB2 pathway. The FASEB Journal, 32(1), 488.

https://doi.org/10.1096%2Ffj.201700670R 

Wagner, S., Manickam, R., Brotto, M., & Tipparaju, S. M. (2022). NAD+ centric mechanisms and molecular determinants of skeletal muscle disease and aging. Molecular and cellular biochemistry, 477(6), 1829-1848.

https://doi.org/10.1007/s11010-022-04408-1