The musculoskeletal system performs four major and basic functions:
- It forms the structural framework of the body
- It helps in mobility
- It protects the soft tissues in the body like lungs, heart, brain, etc.
- It works as a storehouse of calcium for maintaining internal equilibrium (homeostasis)
The first two of these functions become jeopardized in the elderly very frequently; musculoskeletal pain is a major cause of physical pain and disability in most of the elderly.
Several factors contribute to the aging of the musculoskeletal system:
- Aging of individual components of the musculo-skeletal system like joint capsule, cartilage, etc.
- Aging and degeneration of joints (osteoarthritis)
- Loss of muscle mass (sarcopenia) and reduced movement
- Rise of age related falls and morbidity due to other chronic diseases
- High incidence of age related diseases like polymyalgia rheumatica, Paget’s disease and crystal related arthropathies in the elderly
What are the reasons behind high prevalence of bone and muscle aging in elderly?
- Increased lifespan and life expectancies leads to longer duration of wear and tear of muscles and bones
- As the age advances, the repair system lacks behind, leading to permanent tissue damage
- Evolutionarily the human Skeleton is not designed to take the kind of stresses it is subjected to. Human spine specifically gets strained in the upright position and the discomfort only gets worse with the added years.
- Sedentary life style leads to decreased usage of muscles and underused muscles suffer a lot of disuse atrophy (decreased muscle mass)
- Decreased capacity of wound healing and delayed repair in case of an injury
Articular Cartilage: This is the cartilage that lines the joint surfaces and hence helps in preventing friction when there is a movement at the joint. It also releases the synovial fluid that fills the joint cavity so that the articulating surfaces of bones and cartilage do not touch each other.
In old age however, the articular cartilage wears off causing a painful condition of the joints called osteoarthritis. The synovial fluid also decreases as the age advances. These structural changes in the cartilage lead to inflammation of the underlying bone-ends, causing osteoarthritis.
With diabetes and obesity the chances of osteoarthritis increase by manifold.
Skeleton: The skeleton consists of bones articulated with each other. Weight bearing bones like spine and knee joints are the ones which suffer the most wear and tear.
Once middle age is reached, the total amount of calcium in the bones starts reducing. This change is far more evident in females as the metabolism of bone-calcium is dependent on their sex-hormones like estrogen and progesterone. Decreased bone mineral density (BMD) is a common problem in women approaching menopause and post-menopause. The bones start thinning, and even material strength of bones starts declining, leading to micro-fractures.
Besides hormones, nutrients play an important role in the bone metabolism. Vitamin D and calcium are adequately available but absorption and metabolism is poor in old age. Vitamin D is available from the sunlight. But in elderly the generation of Vitamin D on sun exposure is less.
Bone growth is largely dependent on the movement. Physical activity attenuates the aging of bone, whereas, immobilization is known to cause bone loss.
Soft Tissues: Age related change occur in muscles, which can be summarized as follows:
- Reduced tensile strength
- Reduced elasticity
- Reduced muscle mass
Consequences of bone and joint aging can be listed as:
- Loss of muscle strength
- Reduced range of movement of individual joints
- Joint stiffness and pain
- Difficulty in initiating movement
- Fractures to trivial trauma
- Reduced capacity to move and forced immobilisation
Active lifestyle with regular exercising routine along with healthy nutrition decreases the process of aging of bones and muscles. So it is recommended to continue regular exercises to remain fit throughout the life. It also helps in preventing falls and fractures by keeping bones and muscles strong and sturdy. However, it is best to consult your physician for choosing the exercises that will best suit your body type.
Ask a question regarding Aging of Bones and Joints