Ohio University researchers have pinpointed a critical factor in age-related leg weakness: reduced motor neuron firing rates. This groundbreaking discovery offers new avenues for interventions and treatments, potentially improving the quality of life for older adults by addressing a major public health concern.
The Core Discovery: Motor Neuron Firing Rates
Researchers at the Ohio University Heritage College of Osteopathic Medicine found that older adults experiencing leg extensor weakness exhibit significantly reduced motor neuron firing rates. Motor neurons are essential for transmitting signals from the brain and spinal cord to muscles, enabling movement. When these signals are diminished, muscle contractions weaken, leading to overall muscle weakness.
- The study specifically focused on the vastus lateralis muscle, part of the quadriceps in the upper thigh.
- A computer model predicted that decreased motor neuron signaling could reduce muscle strength by up to 26 percent.
Implications for Future Interventions
This novel finding highlights the crucial role of motor unit firing rates in maintaining muscle health and function. Understanding this relationship opens doors for targeted therapies aimed at preserving and improving muscle function in the aging population.
Brian Clark, Ph.D., executive director of the Ohio Musculoskeletal and Neurological Institute (OMNI) and co-author, emphasized the importance of this discovery: “Understanding what causes muscle weakness is essential if we want to develop effective interventions. Now that this link has been identified, we can begin to focus on strategies to maintain muscle health in aging patients. These strategies may include specific types of exercise training as well as neurotherapeutics to enhance firing rates.”
Maintaining Muscle Health as You Age
While decreased motor nerve firing can occur naturally with age, certain lifestyle choices can help mitigate its effects. The National Institute of Arthritis and Musculoskeletal and Skin Diseases recommends:
- Engaging in regular physical activity, particularly strength training.
- Maintaining a nutritious diet.
These practices can help maintain or improve muscle function as individuals age.
The Research Team
The study was led by Nathan Wages, Ph.D., a former post-doctoral fellow at Ohio University and now an assistant professor at Rutgers University. Key co-authors from the Heritage College include Brian Clark, Ph.D., Leatha Clark, D.P.T., and Dallin Tavoian, Ph.D. Additional collaborators came from Wright State University and the University of Missouri.
Sources
- Heritage College of Osteopathic Medicine study reveals key insights into leg weakness in older adults, Ohio University.