How are Flexibility and Mobility defined and what are their differences
Flexibility and mobility play a very important role in injury prevention as well as injury rehabilitation. Flexibility is simply defined as the ability of the musculotendinous unit (relating to both muscular and tendinous tissues) to lengthen. While mobility is defined as the ability to actively move a joint or a series of joints through a full, unrestricted, pain-free range of motion.
Flexibility is defined by the ability of the muscle to lengthen and return to its original length after. More often than not, we require an external force to help us with elongating our muscles in a stretch further than what our muscles are accustomed to. This action causes the muscle spindle to send impulses to the central nervous system to force our muscles to contract as a response to protect the body from injury – this is why stretching hurts sometimes. Prolonged stretching will habituate the muscle spindle to the new length of muscle, thus reducing its signals to the brain and improving our flexibility.
Mobility is based on the combination of the joint(s) range of motion, which may be limited by the shape of the articulating surface, and the capsular and ligamentous structures surrounding that joint. It also depends on the neuromuscular ability of the joint top move through the range of motion.
Flexibility and mobility can be reviewed in relation to movement of only one joint, such as the knee, or movements involving a whole series of joints, such as the spinal vertebral joints, that must all move together to allow smooth bending or rotation of the trunk. Lack of flexibility and mobility in one joint or movement can affect the entire kinetic chain.
Importance of flexibility and mobility in ADL and roles in sports
In most people, it is important to have “normal” flexibility and mobility (within normal range of motion) for the “activity of daily living (ADL)”. Being flexible and having full joint mobility can significantly improve the quality of living life including reducing day-to-day pain and increasing vascular health.
In comparison, sports persons or athletes require increased flexibility and mobility to perform at an enhanced level. Examples of athletes requiring high flexibility and mobility are those competing in gymnastics, ballet, diving, karate and, especially, dance. That is not to say that many other sports do not also require a high level of flexibility for superior performance.
It is also widely accepted that flexibility is fundamental for improving performance in physical activities. Numerous studies show that regular stretching and maintaining good flexibility and mobility helps in reducing injury and preventing from injury to occur.
Anatomical factors that limit flexibility and mobility
There are several anatomical factors that can limit a person’s flexibility and/or mobility. Muscles and their tendon, along with their surrounding facial sheath, are most responsible for limiting range of motion. Connective tissue surrounding the joint such as ligament on the joint capsule has some elasticity, but it can often suffer from contracture due to prolonged immobilization.
In most cases we rely on bony prominences to stop movements at normal end points in the range. However, if we look at the example of a fractured elbow, this might lay down excess calcium in the joint space, causing the joint to lose its ability to fully extend. Fat also can limit the to movement, such as in obese people, where underlying fat in the abdominal can restrict them from bending and touching their toes. Skin contracture due to laceration or burning scars can limit flexibility due to inelasticity of the scar tissue formed at the site.
Hyper or Hypo mobility and flexibility
Hyper-mobility / -flexibility simply refers to joints that stretch further than normal. For instance, a person with hypermobility or flexibility may be able to extent their thumb backward to their wrist or extend their elbow or knee beyond than normal range of motion. This condition can affect one or multiple joints and is named joint hypermobility syndrome (JHS). Hypermobility syndrome results from very weak connective tissue, meaning the tissues that holding a joint together, mainly ligament and joint capsule, are too loose. In some cases, weak muscles around the joint also can contribute to hypermobility.
Benign hypermobility syndrome appears without any underlying health condition. It can be caused by bone shape or depth of the joint sockets, muscle tone or strength, poor joint sense or simply from a family history of hypermobility. In strange cases, the hypermobility can occur due to an underlying medical condition. These include:
- Down syndrome, which is developmental disability;
- Cleidocranial dysostosis, which is an inherited bone development disorder;
- Ehlers-danlos syndrome, an inherited condition which affects the elasticity;and,
- Marfan syndrome, which is a connective tissue disorder
Hypermobility or flexibility can be diagnosed by few test, Beighton score is a quick measure of the flexibility which we will discuss in later paragraph.
Hypomobility or hypoflexible joints are a condition in which the joints are too tight and cause a decrease range of motion. In this condition, the ligament and tissue structure around the joints are too short and tight which results in limited range of movement of the joint. Over time, the connective tissue around the joint becomes stiff due to lack of motion, which can adversely affect the surrounding bones, muscles, or joints. Untreated hypomobility or hypoflexibility condition may lead to severe adhesive and may cause degeneration to the joint. The sign and symptoms of hypomobile syndrome are joint pain, inability to stretch in the normal range of motion, and pain due to lack of movement/stiffness. The lack of mobility and flexibility can also lead to muscular contracture.
How to improve flexibility and mobility
In general, people can lose their ability to be flexible and mobile through prolonged inactivity. Musculoskeletal injuries also can be the cause of immobility. Thus, improving or regaining any lost flexibility and mobility is crucial.
There are many possible ways to improve flexibility of the muscle and the joints. The flexibility can be improved by incorporating exercises into your daily routine. The most common exercises given in order to improve flexibility and mobility are various type of stretches. Unfortunately, a repetitive routine of stretching can become demotivating, hence there are other activities that can be merged with the stretching routine for better benefits.
For example, activities such as Yoga, Pilates, Tai Chi are highly recommended to improve stretching.
- Pilates helps to build strength and flexibility;
- Yoga focuses mainly on increasing the joint range of motion; while,
- Tai chi loosens and stretches the whole-body muscles.
The goal of any effective stretching program should be to improve the range of motion, at a given articulation by altering the extensibility of the neuromusculo-tendinous units that produce movement at that joint.
When injuries occur, soft tissues will lose some of their ability to tolerate the demands of functional loading. Applying manual therapy techniques can help in injury rehabilitation to improve mobility and range of motion. In addition, soft-tissue mobilization involves specific, graded and progressive application of force using physiologic, accessory, or combined techniques. This helps to promote collagen synthesis, orientation, and bonding in early phase of healing process.
Further techniques that can be applied are myofascial release, which helps in relieving soft tissue from the abnormal grip of tight fascia. This technique is used to correct soft-tissue problems in muscle, tendon and fascia caused by the formation of fibrotic adhesions that result from acute injury, repetitive and/or overuse injuries.
Flexibility and mobility for injury prevention
In general, a normal range of flexibility and mobility can prevent a person from getting injured. In the case of an athlete who lacks mobility, they are more likely to have muscle imbalance or muscle weakness: Oftentimes the primary reason for an athlete to get injured is muscular weakness or tightness because the tight muscle will restrict the joint to move along the range of movement. Thus, practicing good flexibility and mobility training in a daily training routine is crucial. Stretching before and after working out or sports specific training will help the muscles to maintain their extensibility andelasticity. When the muscle and joint are able to move in normal range, it can prevent from the injury to occur.
Flexibility and mobility with aging
As we get older, we become less mobile, and the physical activities will be reduced. Due to immobility we often lose the strength which is required to maintain heathy range of motion. Besides that, the connective tissues lose their collagen, causing the elasticity to also degrade. Ultimately, age related loss of muscle may decrease mobility.
In fact, the whole aging process affects the flexibility and mobility due to our body’s physiological changes. To prevent t getting worse, practicing stretching is vital to mobility and muscle recovery. Continued stretching helps our body to stay flexible, helps release the fascia tissue, which connects the muscles, bones, tendons, and blood. When the fascia is healthy, it allows the muscles to glide easily against each other, thus directly helping to prevent injuries.
Does lack of or excessive flexibility and mobility have long term effects?
Indeed, yes, it can have a long term effect. In both hypo or hyperflexibility/mobility cases muscles and joints and the structures around will suffer from wear and tear in long run. Lack of mobility/flexibility will lead to stiffness and degeneration, especially on the spine. In particular for hypermobility or flexibility, the chances to dislocate joints will be high and can also lead to joint arthritis due to overuse.
Reference: Beighton score
The Beighton score is a commonly used screening technique to assess hypermobility or laxity. This is a nine-point scale and requires the performance of 5 manoeuvres, four passive bilateral and one active unilateral performance. Below stated the figure on how to test your hypermobility/flexibility. You also can assess yourself by clicking on this link.