Age Related Changes to the Musculoskeletal System
The musculoskeletal system is made up of skeletal muscle, bones and joints that work together to produce movement to the human body. Age related changes fall under two categories namely, Structural and Functional.
Being aware of such changes to your body as we age may help influence your training methods and assist in the fight against the battle of ageing.
It is believed with age the loss of muscle mass, size and strength is likely to be due to a reduction in physical activity. However, those physically active maintain fibre size until roughly the age of 60. Regardless of activity levels the composition of skeletal muscle changes significantly and the two primary types of Fibre (Type I and Type II) exhibit specific characteristics resulting in a decrease of the whole muscle size. Type I relates to aerobic endurance performance (marathon runners) whilst Type II fibres relate more so to power / resistance (sprinters). Research shows the size of Type II fibres decrease with age along with a decrease in the Type II to Type I fibre ratio.
Bone mass declines with age similar to muscle mass and it is believed that bones peak around the age of 30 thereafter gradually declining. The cause of bone loss is believed to be inactivity, changes to hormone levels and improper nutrition.
Furthermore, there is a significant risk of osteoporosis to those individuals inactive which is characterised by a thinning and weakening of the bones.
Structural changes and weakening of joints with age include microtears, calcification (brittle bones) and an increase in cross linking within joint collagen. Tendons and ligaments shorten which result in a reduction to joint range of motion up to 25% and cross linking results in stiffness. In addition, any weakening leading to injury may result in a decrease in joint stability due to lack of blood supply to cartilage, tendons and ligaments.
In light of the above, it is vital that stability training is taken into consideration and cannot emphasis enough the importance of good core management to fight chronic pain issues. Poor core stability increases the risks of axial an appendicular conditions in older adults.
A loss of structural integrity usually leads to a decrease in functional capacity. This may result in a decrement to muscular strength, power and endurance. Furthermore, joints may be weakened resulting in a loss of mobility and independence.
Potential fitness considerations to be considered in relation to the musculoskeletal system are as follows:-
Reduced mucular strength
Reduced muscular power
Reduced muscular endurance
Reduced flexibility and range of motion
Reduced balance and coordination
Reduced postural stability
Bones less resilient to stress and more susceptible to fracture
Stiffer, less mobile joints
Reduced shock absorption in the joints
Fortunately, the positive effects of physical activity for the musculoskeletal system is simple...it dramatically reduces the effects of ageing by allowing muscle mass, strength and power to be maintained.
Further, training significantly affects the health of bones by retaining bone mass and it is recommended that weight bearing and strength training be utilised in order to add mechanical force to stress the bone. Of course, it is to be noted that diet and hormonal considerations for postmenopausal women play a role in maintenance also.
With regards to joint health, there is a debate as to whether physical activity prevents osteoarthritis or overuse may cause osteoarthritis. Either way, it is recommended that aerobic, muscular strengthening and water-based exercise be used as therapy for osteoarthritis.
In conclusion, physical activity plays a vital role in reducing the effects of ageing on all components of musculoskeletal health.