Motor control week 12 quiz

Understanding Fatigue: Components, Modulators, and Sense of Effort

• Fatigue is a self-reported feeling of tiredness that results in decreased performance of a task and difficulty in initiating or sustaining voluntary activities.
• Fatigue has been historically attributed to both peripheral and central factors, including lactic acid build-up, lack of oxygen, failure of muscle contraction, and responses in the central nervous system.
• Fatigue is derived from two interdependent attributes: perceived fatigability and performance fatigability, which are specific to the person and their traits, capacity, and experiences.
• Performance fatigability is the decline in an objective measure of performance over a discrete period and is measured only during activity.
• Perceived fatigability is the change in sensations, homeostasis, and the psychological state of the individual and can be measured at rest or during activity.
• Factors that modulate fatiguability include psychological, homeostatic, and environmental factors, as well as muscle spindle input, motoneuron firing, and contractile function.
• Sense of effort is the conscious perception of the intensity of physical activity and can be measured by the Rate of Perceived Exertion (RPE) using the Borg Scale.
• A lack of psychological monitoring and intervention can contribute to perceived fatiguability, as seen in the case of the 2004 Olympic Games women's eights rowing final.
• Motor unit recruitment and rate coding, muscle spindle input, and cortical drive can influence motoneuron firing and contribute to fatigue.
• A decrease in ATP and increased ADP disrupts excitation-contraction coupling, which can decrease graded potentials, Ca2+ release, and sliding filament.
• Reduced blood flow to muscles can decrease oxygen and glucose necessary for aerobic ATP production and the removal of metabolic by-products.
• Understanding the components, modulators, and sense of effort of fatigue can aid in managing and preventing fatigue in clinical and athletic settings.

Understanding Concussion and Traumatic Brain Injury

• Concussion is a mild traumatic brain injury caused by a direct blow to the head, face, neck, or elsewhere on the body with an impulsive force transmitted to the head.
• Sports-related concussions make up about 20% of all concussions, with women athletes being more likely to suffer and experience more severe symptoms.
• The most common symptoms of a concussion include headache, difficulty concentrating, neck pain, nausea or vomiting, dizziness, confusion, blurred vision, and sensitivity to light and noise.
• The pathophysiology of a concussion involves neuronal cell membrane disruption and axonal stretching that causes a cascade of events, including dysregulation of the flow of ions across the membrane, depletion of cell energy, and excess calcium into the neuronal cell body.
• The most serious signs of a concussion include loss of consciousness, tonic posturing (such as the fencing response), balance disturbance and ataxia, and cerebellar signs.
• The Sport Concussion Assessment Tool (SCAT 5) is the gold standard for evaluating concussions, including balance tests and vestibular/ocular-motor screening.
• Post-concussion syndrome is a condition where symptoms of a concussion persist beyond 7-10 days, and can include cognitive, sleep, mood, and physical symptoms.
• Risk factors for poorer recovery from a concussion include a history of past concussions, severity of initial symptoms, migraine headaches or depression, and being a child or adolescent, especially female.
• Treatment for a concussion involves 1-2 days of cognitive and physical rest, followed by gradual activity increase.
• Subconcussive impacts are enough force to injure axonal or neuronal integrity, but not result in clinical symptoms at the time of injury, and may lead to chronic traumatic encephalopathy (CTE).
• CTE is a long-term brain damage that can result from exposure to head acceleration events, even in the absence of a diagnosis of concussion, and is associated with Alzheimer's disease/dementia, Parkinson's disease, and motor neuron disease.
• Understanding the signs, symptoms, and treatment of concussion and traumatic brain injury is crucial, especially for individuals participating in high-risk sports or activities.