Static stretching:

• Static stretching involves moving the muscle or joint into an elongated position and holding the position for an extended period.

• Historically, this type of stretching has been used to prepare the muscle for exercise.

Dynamic stretching:

• Dynamic or ballistic stretching is when the muscles and joints are taken through their range of motion during movement. This type of practice is more specific to preparation for exercise and sports in particular

• During the rehabilitation process care should be taken to not ‘bounce’ the muscle that is recovering from injury

• Dynamic stretches have been shown to significantly increase tendon flexibility and elasticity and have been promoted for end-stage rehabilitation for tendon injuries

• However, ballistic stretching involves eccentric contractions during the stretch phase, which may results in soreness or injury and therefore care should be taken when incorporating such stretches

Static stretching does NOT improve muscle length

• Static stretching changes the muscle-tendon functions (range of motion and maximum voluntary contraction), which are related to mechanical changes of the muscle but not the actual tendon structure

• In a 2019 study there was a decrease in muscle-tendon stiffness after static stretching observed immediately, but not 5 or 10min after stretching

Static stretching does NOT prevent injury

• Warm-ups are typically composed of a submaximal aerobic activity, stretching and a sport-specific activity

• The stretching portion traditionally incorporated static stretching

• However, there are numerous of studies demonstrating static stretching induced performance impairments

• A number of researches have concluded that stretching has no effect on injury prevention (Gleim and McHugh 1997; Herbert and Gabriel 2002; Small et al. 2008).

• Sustained static stretching can impair subsequent performance;

• Maximal voluntary contraction

• Isometric force and isokinetic torque

• Training-related strength measures such as one repetition maximum lifts

• Power-related performance measured such as vertical jump (jump height)

• Sprints running economy (reaction, movement time and balance)

• Agility

• The acute negative effects of stretching seem to be associated with stretches at a duration of 60 seconds, while stretches of shorter duration may have less significant deficits

• The most powerful injury prevention tool available is strength training, at increasing loads over a 6-8 week period.

What is safe stretching? When Should I be stretching?

• It is important to differentiate between pre-exercise stretching (where stretching does not appear to prevent injury) and regular stretching outside periods of exercise (where there is some clinical and basic science evidence suggesting stretching may prevent injury)

• Additionally, stretching does not seem to reduce the effects of DOMS (Delayed onset of Muscle Soreness)

• Dynamic stretching which involves controlled movement through the active range of motion should be the choice pre-exercise.

The effect of stretching after exercise

• Athletes often stretch after exercise in an attempt to improve range of motion and reduce the perception of musculotendinous stiffness. While it is a regular component of post-exercise regimens, there is limited evidence of the effect of stretching on various aspects of recovery

• Lund et al. suggested that stretching following bouts of eccentric exercise may delay recovery. In a study investigating the effect of static stretching on DOMS following eccentric quadriceps of seven untrained females, they reported that recovery of strength was impaired in the group who stretched their quadriceps for three repetitions of 30 seconds each day after exercise caused further mechanical disruption and exacerbated muscle damage

• In contrast, Torres et al. reported no effect of daily stretching on maximum voluntary contraction of the quadriceps following eccentric exercise in healthy untrained men .

Key messages

1. Perform dynamic stretching before exercise.
2. You can perform static stretches after exercise or at any other time to give you temporary relief of stiffness or pain.