is the range of motion possible around a specific joint or series
of articulations. Flexibility is specific to a given joint or
movement. A person may not be able to function normally if a
joint lacks normal movement. The ability to move a joint through
an adequate range of movement is important for daily activities
in general as well a sports performance. For example, a sprinter
may be handicapped by tight, inelastic hamstring muscles since
the ability to flex the hip joint will be limited, thus shortening
stride length. Activities such as gymnastics, ballet, diving,
karate, and yoga require improved flexibility or even the ability
to hyperextend some joints for superior performance.
On the other hand, most leisure or recreational activities
require only normal amounts of flexibility. The idea that
good flexibility is essential for successful performance is based
on anecdotal rather than scientific evidence.
Adequate range of movement may be more important for long
term injury prevention. Individuals involved with physical activity
who have poor flexibility (specific or general) risks exceeding
the extensibility limits of the musculoskeletal unit. Once flexibility
is assessed and flexibility insufficiency are identified, a stretching
program can be customized, emphasizing those areas in need of
improvement. See flexibility assessments
and Joint Ranges of Motion.
Four basic types of stretch techniques include ballistic,
dynamic, static, and proprioceptive neuromuscular facilitation
The oldest technique is the ballistic stretch which makes
use of repetitive bouncing movements. It has been virtually abandoned
by almost all experts in the field due to safety concerns.
Dynamic stretching incorporates movements that mimic a specific
sport or exercise in an exaggerated yet controlled manner; often
include during the warm-up or in preparation for a sports event.
The static technique involves passively stretching a muscle
to the point of mild discomfort by holding it in a maximal stretch
for an extended period. It remains a very effective, relatively
safe, and popular method of stretching. Recommendations for the
optimal holding time are varied, ranging from 10 seconds to 60
seconds. See stretches in the Exercise
PNF (proprioceptive neuromuscular facilitation) techniques
involve a partner actively stretching the participant by some
combination of altering contraction and relaxation of both agonist and antagonist
muscles. Some of the different PNF techniques used include slow
reversal hold, contract relax, and hold relax. PNF stretching
usually involves a 10 second push phase followed by a 10 second
relaxation phase, typically repeated a few times. PNF stretching
is capable of producing greater improvement in flexibility compared
to other techniques. Its disadvantage is that, it typically requires
a partner, although stretching with a partner may have some motivational
advantage for some individuals. Examples include:
Ninos J (2001) has proposed particular PNF stretches that
can be performed by an individual when a partner is unavailable
(eg: modified versions of the standing
single leg hamstring stretch and standing
Contrary to popular belief, stretching before a workout
does not appear to decrease the occurrence of injury. The
risk of injury seems to be about equal to those who stretch and
those who do not stretch before exercise. The warm-up,
not stretching, seems to be the important deterrent for injury,
performed before an exercise bout. Stretching seems to offer
more long term benefit such as maintaining functional flexibility
and correcting particular muscular
(1999) review of the literature found three articles that suggested
stretching was beneficial included a co-intervention of warm-up.
One study found stretching was associated with less groin/buttock
problems in cyclists, but only in women. Five studies suggesting
no difference in injury rates between stretchers and non-stretchers
and three suggesting stretching was detrimental. One reason stretching
is thought to be ineffective in reducing the risk of injury is
the fact that most muscle injuries occur when the muscle is eccentrically
contracted within the normal range of motion (Shrier 1999). It
seems more flexible individuals do not necessarily have less
incidence of injury (Gleim 1997). In some cases, those with greater
flexibility may actually experience more injury, particularly
if the excessive flexibility compromises joint integrity (Surberg
1983; Jones 1997). Although excessive flexibility may contribute
to joint laxity, flexibility and joint integrity are not necessarily
mutually exclusive. It may be possible for a joint to possess
a combination of exceptional flexibility and excellent joint
Greater flexibility may impair performance in sports that
do not require a high degree of flexibility such as running.
Runners with less flexibility are actually more efficient at
running (Jones 2002). Intense static stretching may also reduce
maximum force production. The loss of voluntary strength and
muscular power may last up to one hour after the static stretch
(Evetovich 2003, Young 2003). People who participate in activities
that require more than average flexibility (eg: gymnasts, dancers,
figure skaters) may still find stretching beneficial to their
The ACSM recommends flexibility training a minimum 2 to 3
days per week holding each stretch for 10 to 30 seconds to mild
discomfort; 3 to 4 repetitions per stretch. On PNF stretches,
ACSM suggests a contract 6 seconds followed by a 10 to 30 second
McCallister et. al. (2004) found that longer recovery days
between stretching seemed to enhance stand and reach measurements:
Stand & Reach (cm)
This data suggests it may not be
necessary to stretch daily, but instead take a few days recovery
Weight training and stretching exercises have been considered
complimentary. Resistance training can increase the stiffness
of the tendon structures as well as strengthen the muscles, whereas
static stretching changes the viscosity of tendon structures,
but not its elasticity (Kubo et. al 2002).
Many full range weight training exercises could be considered
a kind of dynamic stretch under a load. These types of weight
training exercises can improve and maintain a degree of flexibility
depending on their movement, range of motion in which they are
performed, and existing levels of flexibility.
Although stretching does not seem to offer many short term
benefits when performed before exercise, stretching does seem
to offer other long term benefits. Improved flexibility may help
alleviate and help prevent back and other orthopedic problems.
Individuals with certain muscular imbalances or postural problems
can benefit from stretching. Stretching can help maintain flexibility
which may otherwise decline with age or inactivity due to an
injury. Stretching may be more safely performed after dynamic
exercise, when muscles are warm. Unless an activity requires
extreme flexibility, stretching before is probably unnecessary.
And even then, stretches should be performed after a warmup.
American College of Sports Medicine, (2000) ACSM's Guidelines
for Exercise Testing and Prescription, 6; 158.
Bracko, MR (2002). Can stretching prior to exercise and
sports improve performance and prevent injury? ACSM's Health
& Fitness Journal, 6(5), 17-22.
Evetovich TK, Nauman NJ, Conley DS, Todd JB (2003). Effect
of static stretching of the biceps brachii on torque, electromyography,
and mechanomyography during concentric isokinetic muscle actions.
J Strength Cond Res. 17(3):484-8.
Gleim, GW & McHugh, MP (1997). Flexibility and its
effects on sports injury and performance. Sports Medicine, 24(5),
Hedrick A (2000). Dynamic flexibility training. Strength
and Conditioning Journal 22, 33-38.
Herbert, RD & Gabriel, M (2002). Effects of stretching
before and after exercising on muscle soreness an risk of injury:
Systematic review. British Medical Journal, 325 (7362), 468-470.
Jones AM (2002). Running economy is negatively related
to sit-and-reach test performance in international-standard distance
runners. Int J Sports Med. 23(1):40-3.
Jones BH (1997). The role of medical surveillance and research
in army injury prevention. American College of Sports Medicine
Conference abstract, Denver.
Kubo K , Kanehisa H, and Fukunaga T (2002). Effects of
resistance and stretching training programmes o the viscoelastic
properties of human tendon structures in vivo. Journal of Physiology
McCallister TL, et. al. (2004). Days of rest between stretching
bouts increased hamstring flexibility. Journal of Athletic Training.
Supplement 39(2), 99-100.
Ninos J (2001). PNF-Self Stretching Techniques, Strength
and Conditioning Journal 23(4); 28-29.
Shellock, FG & Prentice, WE,(1985). Warming-Up and
Stretching for Improved Physical Performance and Prevention of
Sports-Related Injuries, Sports Medicine, 2: 267-278.
Shrier I (1999). Stretching before exercise does not reduce
the risk of local muscle injury: a critical review of the clinical
and basic science literature. Clin J Sport Med. 9(4): 221-7.
Surberg PR (1983) flexibility exercise re-examined. Athl
Young WB, Behm DG (2003) Effects of running, static stretching
and practice jumps on explosive force production and jumping
performance. J Sports Med Phys Fitness. 43(1):21-7.