Factors Affecting Flexibility and Joint Mobility [ UPDATED 12/23/2019 ]
As a professional personal trainer or certified coach, it’s vital that you consider all factors affecting flexibility and joint mobility prior to designing a comprehensive performance training program.
Joint structure and connective tissue play a significant role in a muscle’s ability to lengthen and in joint range of motion. Factors that cannot be changed such as age and sex of the athlete should be considered when assessing and designing a flexibility program.
Other factors affecting flexibility and joint mobility that can be modified to improve flexibility include injury, tissue bulk, quality of movement, and activity level.
What Affects Flexibility and Joint Mobility
Excessive muscle or adipose tissue bulk impedes normal joint range of motion. When adding muscle bulk or considering an athlete’s mass, the sport and position should be taken into consideration in the design of their strength and conditioning program. For example, large biceps and deltoids may make it difficult for an athlete to stretch their triceps.
Quality of Movement
Although a comprehensive strength training program has a positive effect on flexibility gains, heavy strength training through a limited range of motion during an exercise can decrease range of motion.
To prevent a range of motion loss the agonist and antagonist muscle groups should be strengthened through the full available range of motion. Lifting technique also contributes to the development of over and underactive muscle groups. For example, if an athlete’s knee moves inward (valgus knee) they are likely to develop overactive adductors, tensor fascia latte, vastus lateralis, and underactive gluteus medius, gluteus maximus and vastus medialis oblique weakness.
Active individuals are generally more flexible than inactive individuals. This is true for individuals who participate in regular flexibility routines and for individuals participating in other physical activity. Men and women have proven more flexible in participating in functional activities and/or strength training regimens.
A study by Simao concluded strength training alone increased flexibility in previously untrained women; however, when strength and flexibility training is combined flexibility will be affected to a greater extent. Although physical activity leads to better mobility and flexibility than in untrained individuals, a stretching routine should be incorporated into a fitness program if increase joint motion is to be maintained or increased.
Injury or Dysfunction
Injury often occurs when a muscle or joint is forced beyond its normal active limits. If the muscle does not have enough elasticity to compensate for the additional stretch, the musculotendinous unit will likely be injured resulting in a muscle strain. Hamstring and hip flexor strains are common in sports requiring short explosive bursts of speed.
Joint sprains are forceful wrenching or twisting of a joint that stretches or tears its ligaments but does not dislocate the bones. In this case, the ligaments are forced beyond their normal capacity. Ankle sprains are common and often result in a range of motion loss when not managed effectively.
When muscle tissue is injured or degenerates over time fibrosis occurs. Fibrosis is the replacement of muscle fibers by fibrous scar tissue. Due to this process muscle tissue regeneration can occur only to a limited extent. Through the formation of fibrous tissue, these adhesions can compromise tissue flexibility if not managed effectively.
Furthermore, injury can affect the body’s ability to function through the kinetic chain. For example, if an athlete with a history of ankle sprains and decrease dorsiflexion attempts an overhead squat their technique will be compromised and compensations will be noted through the movement.
Age & Sex
Younger individuals tend to be more flexible than older individuals. With aging, humans undergo a slow, progressive loss of skeletal muscle mass that is replaced by fibrous connective tissue and adipose tissue. This increase in fibrous connective tissue may make it necessary for individuals 65 years and older to hold static stretches for up to 60 seconds compared to the standard 10-30 seconds.
This decline in muscle mass is also linked to decreased levels of physical activity and thus impaired flexibility. Nevertheless, aerobic activities, flexibility, and strength training programs are effective in slowing and even reversing the age-associated decline in muscular performance.
Females tend to be more flexible than males however, both men and women have successfully increased flexibility as a result of a properly designed resistance training program.
How to Measure Flexibility & Joint Mobility
Base can be defined as “the lowest part or foundation of anything.” A baseline is defined as “an observation or value that represents the normal background level of measurable quality.” The operative words in these two accepted definitions are the foundation, the fundamental or essential components of a system or structure, and quality, a range, degree, or grade of excellence. The purpose of baseline testing is to demonstrate the fundamental building blocks of athleticism and preparedness for sport.
Function or functional training is another popular term used to represent movements that are specific to physical activity or sport. The word function is used in nationally recognized movement assessments such as the Functional Movement Screen and Selective Functional Movement Assessment.
Baseline testing data should be taken into consideration with an athlete’s medical history (previous injuries) and sport-specific data (performance and skills) during the goal setting and program design period.
Baseline testing should be specific to the demands of the sport and activity as well as assess or screen the athlete’s functional movement patterns. It identifies an athlete’s attributes of and detriments to athletic performance and competition.
Baseline testing or movement screening predicts an athlete’s predisposition for injury and performance tests provide measurable times and scores to predict skill and ability. Weakness or compensations ultimately cannot be identified without proper screening measures.
What’s the Difference Between a Screen, Test, and Assessment of Flexibility and Mobility?
Many people use these words interchangeably however each has a very different meaning. A functional screen assesses risk for injury. The single-leg squat is a functional screening tool used to identify unilateral compensation. If the knee moves inward that athlete is at an increased risk for injury. A test uses objective measurements to determine an athlete’s performance or ability.
The 20-yard dash would be an example of an objective performance test. This test measures the time it took for the athlete to cross the finish line. It does not take into account the athlete’s technique to complete the task. An assessment examines an athlete’s inability to complete a task. An assessment would identify the dysfunctional movement patterns contributing to the poor running technique.
Baseline Movement Definition
- Screen: A screen measures risk.
- Test: A test measures an athlete’s ability with no interpretation.
- Assessment: An assessment examines or judges an athletes inability or dysfunction.
Baseline Testing Formats
Baseline testing can be best described using the performance pyramid. The pyramid of function or performance pyramid demonstrates how each level of baseline testing builds on the other. Consider the skill necessary to pitch a baseball:
- The pitcher must first possess mobility through the shoulder, neck, and back. Next, the pitcher must have stability in the lower body to shift weight from one foot to the other to generate rotary movement while maintaining balance.
- When the athlete adds speed and power to the weight shift, he or she is able to generate greater ball speed. The athlete will transfer power from the hips to the trunk to the arm, a process known as kinetic linking.
- Last, the athlete will learn control and skill. This will improve his pitch accuracy, conserve energy, and allow the motion to become natural and consistent.
Full joint mobility should be obtained prior to strengthening the surrounding muscles. The mobility allows the body to withstand the eccentric loads that generate power. Without a normal joint range, athletes are at an athletic disadvantage and place themselves at a higher risk for injury.
Your Personal Training Career
Check out what it takes to start a career in personal fitness training. This is your most affordable and fastest way to become a highly qualified personal trainer.
There is always something exciting about earning a new training or coaching certification and applying that new knowledge of how you train your clients. This also helps you hit the reset button.
NESTA coaching programs are open to anyone with a desire to learn and help others. There are no prerequisites.
That’s it for now.