According to the definition Flexibility is the quality of muscles to bend easily without breaking. Humans are born with flexibility and that lose with time. According to Yoga, a stiff body is the result of toxins accumulated in the joints of the body which blocks the flow of prana or vital source that leads to the terminal illness. Being limber provides a better flow of prana, supple joints and conducive to good health. As the coronavirus COVID-19 is the majorly spread disease all over the world and the comorbidity is the major risk factor of the disease, a healthy immunity becomes the essential part of lifestyle evidently. Due to the pandemic, people are now becoming more cautious towards fitness and following many online Yoga programs for their mental and physical health.

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“How long will it take to be flexible and open up my splits?” is one of the common questions I have been asked from many of my clients at the beginner level. With factors like genes, previous training and age, gender and hormones are also major factors to decide the efforts and duration of training for opening of muscles. I always answer them while keeping all factors in mind.

How Flexibility Works?

The nerve endings that relay all the information about the musculoskeletal system to the central nervous system are called Proprioceptors. The proprioceptor detects any changes in physical displacement (movement or position) and any changes in tension or force, within the body. Though there are many proprioceptors in the body, those related to stretching are found in tendons and in muscle fibers and are called Muscle Spindles and Golgi tendon organ (GTO)

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When there is stretch in the muscle, the muscle spindle also stretches. Now the muscle spindle records the change in length of the muscle due to stretching and sends a signal to the brain through the spine. Now the brain comes to know that stretch is going out of the usual range of the muscle, so it sends a signal of Stretch Reflex (contract a stretched muscle) to your stretched muscle to prevent injury. Due to which the muscle follows the order of the brain and causing muscles to contract. That is why you feel this shaking of legs in deep stretches of your splits. The basic function of muscle spindle is to help maintain muscle tone and to protect the body from injury.

The Golgi tendon organ records the change in tension, and the rate of change in the tension, and sends signals to the spine to convey this information.’ When this tension exceeds a certain threshold it triggers a lengthening reaction that inhibits the muscles from contracting and causes relaxation, also called Autogenic Inhibition.

Both of the proprioceptors work perfectly with muscle lengthening and prevent injury during stretching of muscles. One of the reasons for holding a stretch for a prolonged period of time is that we hold the muscle in a stretched position, the muscle spindle habituates and reduces its signaling and register new length of muscles. This improves the flexibility and holding capacity of the stretch.

When the same process is working out in both male and female for muscle lengthening then why does everybody have this statement in their mind, that girls are more flexible than boys. Is this training or girls naturally bendy? Why do splits take less time for girls than boys, even though both are going through the same immense pain of stretching? All these questions have answers, let me explain this through science, research and experience.

How Gender Affects Flexibility?

1. Pelvic Anatomy

Previous study suggests that Females are more flexible than male because of Anatomical and Physiological differences in both sexes. According to Micheal J Alter, Author of Science of flexibility, the pelvic area allows women to have a greater range of motion than man. “Man’s pelvic bones are generally heavier and rougher the cavity is less spacious, and the pubic arch and sacrum are narrower and the acetabula are closer together than women’s. Women have broader and shallower hips than men, this shallowness of the female pelvis permits a greater degree of joint range of motion than man”, said M. Alter.

2. Elbow Hyperextension

Micheal described that “Women usually have a greater range of extension in the elbow. This hyperextension ability is sometimes linked to olecranon”.

At the bottom of the back of humerus is a notch, called the olecranon fossa. At the top, front of the ulna, is a knob of bone called the olecranon, which just happens to fit into the fossa of the humerus. It’s got a little hook on it.

Elbow Hyperextension is limited by contact of the olecranon process of ulna with the olecranon fossa of the humerus. When you reach the limit of maximum ROM, you may feel compression where the two bones are pressed into each other and tension, where the muscles and the joints capsules are under stress. That disrupts the hyperextension ability of the elbow.

If an olecranon is small or the groove is deep, you’ll be able to move it 180 degrees. People who can hyperextend their elbows can do that simply because their bones are different in structure. The ability of Hyperextension in the women is simply due to the  shorter upper curve of the olecranon process of the elbow than men.

3. Muscle Mass

Stiffness is correlated to muscle mass and thickness. Women have less resistance to stretch then man which is a result of their lower muscle mass than men. According to M. Alter, each type of tissue plays a specific role in joint stiffness: "The joint capsule and ligaments are the most important factors, accounting for 47 percent of the stiffness, followed by the muscle's fascia (41 percent), the tendons (10 percent), and skin (2 percent)". He said that “the efforts to increase flexibility should be directed at the muscle's fascia rather than tendons and ligaments because it has the most elastic tissue, and tendons & ligaments are less elastic and does not support prolonged stretching movement.

4. Relaxin Hormone

Relaxin is the hormone which plays an important part to increase laxity (looseness) in ligaments during pregnancy. In females, it is secreted in blood circulation by corpus luteum in the ovary, during pregnancy it is also released from placenta. In men, relaxin is secreted from the prostate gland and can be found in the semen, but is not generally found in the blood circulation. Role of relaxin can be understood better during female menstrual cycle and pregnancy whereas relaxin in men is not yet completely cleared. However, there is evidence that it may increase the movement of sperm cells in the semen. The relaxin hormone is lauded for its function in pregnancy, parturition and other aspects of female reproduction. At the same time, the role of relaxin in male is still debated.

5. Spine Structure

With the great responsibility of nature to be a mother, pregnancy presents immense challenges for the female body. The body adapts some changes naturally to provide a comfortable environment for the fetus inside the womb. This includes several changes in hormones, mental thoughts, frequent mood swings along with body posture and joint stability.

According to the study 19 percent women when standing, they lean back and increase the curvature of spine by 60 percent. Due to this degree of bendiness the curvature takes place in the lower spine, or lumbar region, over three vertebrae in women - compared with only two in men. The change in posture provides an enhanced curvature and bolstering of the lower spine to maintain the activities during pregnancy.

What is The Best Time For Women to Improve Flexibility?

Females have this opportunity to improve their training skills according to their cycle. That’s why it is important for women to get trained and workout according to their menstrual cycle.

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Estrogen has an immense effect on musculoskeletal function. It directly affects the structure and function of musculoskeletal tissues such as muscle, tendon, and ligament. In these musculoskeletal tissues, estrogen improves muscle mass and strength, and is also responsible for new bone formation. There are some days in the cycle when estrogen is at its peak and a woman can feel more strength in her bones. During these days she can be surprised by herself that she can lift more weights than usual. These estrogen boosted days are important for strength training and muscle building.

Similarly, Relaxin levels in the circulation rise after ovulation, during the second half of the menstrual cycle. At this stage it is used to relax the wall of the uterus by inhibiting contractions, and it also prepares the lining of the uterus for pregnancy. If pregnancy does not happen, relaxin levels drop again. So, these are the days when relaxin is high and can provide laxity in ligaments. These days will support female’s bodies to extend their limit and to stretch more.

What Are The Factors That Limits Flexibility?

The most common factors of limiting flexibility are bone structure, muscle mass, excess fatty tissue, connective tissue, physical injury or disability.

Bone Structure

The bone structure of a joint places some limits on flexibility, depending on its type and its current condition. According to which age can also be a factor limiting flexibility since older joints tend not to be as healthy as younger ones.

Muscle Mass

Muscle mass can be a factor when the muscle is so heavily developed that it interrupts the joint’s complete range of motion for example, large hamstrings limit the ability to fully bend the knees). Excess fatty tissue also imposes a similar restriction.

Age

Age is a limiting factor as we can see adults are generally more flexible than older ones, kids are more flexible than adults. After adolescence flexibility level off and then decreases. Although flexibility decreases with age, the loss is minimal in individuals who remain active.

Gender

As we have already discussed how gender plays an important role in flexibility. It's not a myth that females are more flexible than males, if we consider differences in joint structures, hormones and muscle mass. Practice as a key, helps both sexes to achieve great mobility of joints sooner or later.

Temperature

Summers are more supportive to flexibility than winters. Even many people feel much better stretching in the afternoon rather than in the morning. A good warm up is also responsible for a good stretching. The nature of the warm up should be intense enough to cause some sweating but not fatigue. Warm-up is necessary to raise the temperature of the body because joints and muscles offer better flexibility at the body temperature of 1 to 2 degree higher than normal. Stretching without warm-up limits flexibility and can increase the risk of injury.

Training Programs

People under training programs like yoga, gymnastics and dancing seem to be more flexible than those who follow resistance training programs or body building. People in weight training programs majorly focus on large muscles like trapezius, pectoralis major, biceps-triceps, latissimus dorsi and posterior deltoids but only few of them exercise to strengthen rotator cuff muscles like supraspinatus, infraspinatus, subscapularis and teres minor, which are majorly responsible for the external rotation of shoulders. Spending less time with stretching muscles and connective tissues promotes muscle imbalance and reduced range of motion.

Lifestyle

Less active joints can cause chemical changes in connective tissue which restrict flexibility. When connective tissues are unused, it provides significant resistance and limits flexibility. According to the study the stiffness in the hamstring area is due to prolonged sitting. People who spend most of time while sitting or following a sedentary lifestyle are facing more issues of stiffness and reduced flexibility than others who are active physically throughout the day.

5 Important Advantages of Flexibility

• Delays physical deterioration associated with aging
• Decreased risk of injuries and helps muscle to relax after workout.
• Decrease pain and aches in muscles happen due to DOMS.
• Improve range of motion, hence enhanced ability to move joints freely and easily.
• Improve posture and appearance.

Where flexibility is enriched with so many benefits, hypermobility leads to many disadvantages. When connective tissues have too much elasticity then there is increased risk of injury. Too much laxity in the body responsible for unstable joints that demands more control around joints. Muscles or fascia follow elasticity where the elongated muscle can come back to its original resting length again after a passive stretch, whereas ligaments follow the principle of plasticity where it assumes a new and greater length always after a passive stretch. Hypermobility puts a lot of strain on tendons, and ligaments, that occur micro traumas, which can lead to more serious injury, such as joint dislocation, ligament strains and tears, or tendon inflammation. Hypermobility is not bad until and unless following strength training for joints. Strength training is always important with flexibility to provide a better strengthening to muscles, tendons and ligaments and prevent instability of joints.

According to M.Alter, “Flexibility can be developed at any age, through appropriate training. However, the rate of improvement will not be the same at every age nor will the potential for improvement”.

Though Gender is one of the important factors of flexibility, still there is a story of immense pain and struggle behind every flexible human. We all have to go through that tolerance of pain to perform a beautiful shape of Scorpion Bend or a Forearm Wheel. Practice is the only key for both sexes to improve the range of motion and joint mobility, sooner or later. Quarantine is the best time to improve your bends and to build your immunity while staying at home due to COVID-19.

Follow these simple 20 minutes stretching exercises for your splits flexibility at beginner level.

Keep ON your practice and stay safe at home.

Thank You :)

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