Skeletal Muscle and Joint Diseases

Vocabulary flashcards covering skeletal muscle and joint diseases, including sarcopenia metrics, osteoarthritis diagnostic standards, imaging modalities, age-related muscle physiology changes, and exercise intervention recommendations.

Sarcopenia

The age-related loss of skeletal muscle mass and function.

Osteoarthritis

A joint disease characterized by the wearing down of protective articular cartilage on bone, serving as a leading cause of disability worldwide.

Anabolic Resistance

The concept describing how older adults display a blunted or reduced skeletal muscle protein synthesis and strength building response to resistance exercise compared to younger individuals.

NICE Criteria for Osteoarthritis

Consensus-based diagnostic criteria from the National Institute for Health and Care Excellence allowing peripheral joint OA diagnosis on clinical grounds if persistent usage-related joint pain is present, age is $\ge 45\,\text{years}$, and morning stiffness lasts $\le 30\,\text{min}$ (or is absent).

Grim Reaper's Preferred Walking Speed

The walking speed of Death under working conditions identified as $0.82\,\text{m/s}$ (2 miles or about $3\,\text{km}$ per hour) in a 2011 study of healthy men aged 70 and over.

Grim Reaper's Most Likely Maximum Speed

The advised walking speed threshold of $1.36\,\text{m/s}$ (3 miles or about $5\,\text{km}$ per hour) or greater to avoid contact with Death, based on study observations in healthy older men.

Muscle Mass vs. Strength Variance ($R^2$)

The finding that skeletal muscle mass accounts for only $49\%$ ($R^2 = 0.49$) of muscle strength, demonstrating that mass alone does not dictate strength.

Age-Related Fiber Type Shift

The change in muscle composition with aging marked by a decrease in the percentage of Type II fast-twitch fibers and a relative increase/preservation in the proportion of Type I slow-twitch fibers.

Age-Related Myofiber Size Redistribution

The shift in muscle myofiber diameter distribution in older adults toward a higher percentage of smaller myofiber sizes ($2000\text{--}5000\,\mu\text{m}^2$) compared to young adults.

Skeletal Muscle Inflammation in Aging

The increase in skeletal muscle C-reactive protein levels seen in older sedentary individuals compared to young adults.

Tokyo 1964 Olympic Athlete Cohort Study Findings

A comparative study showing former Olympic athletes had lower sarcopenia prevalence (odds ratio $0.49$) but higher prevalence of low physical function (odds ratio $2.60$) and musculoskeletal pain (odds ratio $2.22$) than general older adults, especially those who competed in contact sports.

Economic Cost of Sarcopenia

The annual healthcare burden associated with sarcopenia, estimated at $\$40.4\,\text{billion/year}$.

Sarcopenia Prevalence in Adults Over 80

The prevalence rate of sarcopenia in individuals older than 80 years, affecting $88\%$ of men and $53\%$ of women.

Resistance Exercise Prescription for Sarcopenia

Intervention protocol involving 8–10 exercises targeting major muscle groups, progressive up to $80\%$ 1RM, performed 2–3 times per week for $10\text{--}60\,\text{min}$ per session.

Multicomponent Exercise Modality

An exercise program combining Resistance (R), Endurance (E), Balance (B), and Flexibility (F) performed 2–3 times per week for $45\text{--}60\,\text{min}$, strongly indicated ($+++$) for both sarcopenia and frailty.

Bone Marrow Edema Imaging Detection

An osteoarthritis tissue feature undetectable by Radiograph (X-ray) or Ultrasound, but detectable using Magnetic Resonance Imaging (MRI).

Cartilage Imaging Detection in Osteoarthritis

Joint cartilage degeneration features that are not visible on conventional Radiographs (X-ray), but detectable via MRI and Ultrasound.