What is stretching?
A maneuver used to lengthen shortened soft tissue structures.
Some kinds of stretching:
- Static: Subject not moving
- Passive static: no voluntary or reflex muscular resistance
- Active static: force produced by an opposing muscle action (ie using quad ext to stretch ham)
- Dynamic: How much resistance to active mvt. – Limb repeatedly taken through ROM actively individual.
- Good for high velocity exercises (static sometimes is not beneficial for high velocity).
- Ie: stretch kicks
- Ballistic: Rapid lengthening of the muscle by use of jerking or bouncing movements. Usually not recommended
- Don’t want to set off the primary nerve endings (will cause contraction)
- Too forceful: may cause microtrauma May cause more elastic than plastic changes
- Resistance to Stretch:
- Neurophysical constraints: want to minimize the active contraction of muscle being stretched
- Biomechanical stiffness:
- Stiffness of tissue
- Compliance of tissue: compliant tissue will have good change in length w/ little force required
- Stretch tolerance: Feel less pain for the same force applied to the muscle
- Flexibility: an intrinsic property of body tissues that determines the range of motion that can be achieved without injury at a jt or group of jts.
- Flexibility = stiffness + stretch tolerance -> You go farther because you don’t feel the pain as much (stiffness usually doesn’t change)
- Dependent on the viscoelasticity of muscles, ligaments, and CT.
- Elastic: Permits recovery from deformation or elastic deformation (like a rubber band)
- Viscoelastic deformation: increased muscle length can occur with sufficient duration and magnitude of stretch, but the muscle’s elastic property limits magnitude and duration of the increased length (must stretch for a long time to get permanent changes: plastic deformation)
What is the goal?
- Increase ROM/flexibility
- Improve performance
- Decrease soreness
- Decrease risk of injury
What does the literature say about stretching?
- Stretching to increase jt flexibility: Not due to decrease in muscle stiffness
- Due to indirect decrease of reflex inhibition, therefore changes in viscoelasticity from decreased actin-myosin crossbridges
- Most likely due to stretch tolerance o Duration of increased flexibility after stretching is from 6-90 minutes (hard to maintain because of elasticity)
- Extensive stretching program for several weeks duration has produced increased flexibility lasting for several weeks (ie why ballerinas have to stretch all the time)
- Adverse effects of stretching:
- Stretching before exercise is more likely to cause injury than to prevent it
- Increased compliance decreases amount of energy that can be absorbed
- Muscles can be injured during eccentric activity even though they are not stretched beyond end range
- Mild stretching can cause damage at the cytoskeleton level
- Stretching masks muscle pain (increase stretch tolerance à overstretch)
- Decreased jt stability making jt motion less efficient
- Body positions with dangerous loading effects that can stretch ligaments too far.
- Decreased soreness (DOMS): Evidence doesn’t support stretching to reduce DOMS
- Improved performance: Advantageous for stretch-shortening cycle activity but disadvantage for isometric and concentric performance
- Shown to decrease leg strength, jump height, and peak jump force
- WARM UP PRIOR TO STRETCHING!
- 5-10 minutes aerobic warm-up: You should never stretch a cold muscle
- Stretch to the point of discomfort, not pain. Relax during stretch and you can go farther.
- Must stretch both the agonist and antagonist muscle to avoid muscle imbalances.
- Flexibility is specific to each joint, so you need to include all jts that will be involved the exercise/activity.
- Dosage: 15-60 seconds static (research suggests 30s), 2-3x/week (ACSM rec.)
- Force and duration:
- Plastic deformation: Low force, long duration *
- Elastic deformation: High force, low duration o Must strengthen muscle in the new range!
- Direction of the stretch is applied parallel to the direction of the muscle fibers (in UE/LE usually parallel to the bone, palpate)
Key principles and considerations:
- Posture: Start and end postures based on the proper posture of the associated joints based on physiologic and kinesiologic factors (osteo/arthrokinematics of the jointt)
- Osteo and arthrokinematics: limited motion at the jointt will lead to substitutions and faulty mvt patterns
- Stabilize the origin of the muscle to the insertion. (Usually proximal stabilized on distal)
- Put the muscle opposite of its function to lengthen (ie. All quads cause ext at the knee and hip flexion [rectus only]; so to stretch all you would flex the knee and go into hip ext)
Brody, Lori Thein, and Carrie M. Hall. Therapeutic exercise: moving toward function. 3rd ed.
Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins Health, 2011. Print.
Frese, Ethel. Stretching. DPT 414 Exercise Physiology. Saint Louis University. 10 Feb.
Sample Stretching Workout:
Warm-up: 5-10 min (dynamics are also warm-up like) – aerobic
- Jumping jacks (100)
- Run in place (ideally would be running somewhere…) o Increase HR, warm up muscles for the rest o High knees, butt kickers; vary speeds o Incorporate arm swings: Eye socket/hip socket – through ROM, elbow 90 deg flex (can do slow, med, fast)
- Shoulders: (all directions – abd/add done during jumping jacks, flex/ext with running)
- Horizontal flex/ext: alternate crossing o Small, medium, large Rotations – Fwd/bwd
- Holding onto something for support (wall/pole) o Hip flex/ext (neutral spine, avoid trunk flex/ext) o Hip abd/add (neutral spine, avoid Lat. SB)
- Moving in lines: (across room 2-3 times – obs resp.) o Running: keep running form
- High knees: slower w/ distance, fast reps decrease distance § Butt kickers: slower w/ distance, fast reps decrease distance § Karaoke/grapevine: longer stride, quick step, hip skip.
- Skips (PF and ext; working on contra knee drive)
- Drive up ipsi knee, contra LE ext and PF – UE like running swing
- Vertical height o Straight leg kicks: stretch hams, strength of hip and core stability
- Knee ext, ankle DF – Reach for toes if can, keep eyes forward
- No trunk flex/ext, knee flex o Lunge: hip flex (rectus) – and strengthening other components of LE
- Ipsi step, contra stretch rectus – keep neutral spine, head straight
(hands at hips, heads, or arm swing)
- No SB, hip flex/ext o That football stretch…
- hip flex, horiz abd, ankle DF
- Keep hip neutral, no SB
Static stretching (30 seconds, 3 sets, at least 2-3x/wk) *simplified O/I
- Deltoid (post): Origin from the clavicle and spine of scapula, insert on deltoid tuberosity. Action: shoulder abd, ext o Flex shoulder, Add shoulder, horizontal flexion
- Keep neutral spine, stabilize shoulder/like scapular pinch (no trunk rot., sb, scap protraction)
- Triceps (2jt – long head): Origin scapula and radial sulcus, insert on the olecranon of ulna (action: forearm and shoulder ext) o Shoulder flex, elbow flex
- Reach for either spine or clavicle, look straight – increase stretch by increase elbow flex
- Against wall: Pectoralis major – sternal (Y) and clavicular (T) fibers – Action: Add and MR humerus… will get some ant deltoid stretch too o Clavicular: Origin clavicle, insert bicipial groove on humerus
- T position: Abd, LR o Sternal: Origin sternum, 6 costal cartilage, aponeurosis of ext oblique; insert bicipital groove on humerus
- Y position: Abd, LR o Ideally done in doorway (better stretch than using wall), bent elbows decrease the strain on elbow
- Calf stretch (Gastrocnemius and soleus): “runner stretch” – we have a lot of stances that require significant amounts of DF, but we tend to neglect stretching our PF) o Gastrocsoleus:
- Runner’s Strech: 2 hands push against wall. Contra foot in front, ipsi foot in back. Lean forward into the wall until you feel stretch in the calf. Make sure that your feet are pointed straight in front (lat rot of foot, pronation is subst for short gastrocsoleus)
- OR can do foot up on wall – watch for same subst
- Or can do mountain climbers – watch for same stubst o Soleus (1 jt muscle): put the gastroc in a short-short position to isolate the soleus
- Same stretch as above, but with the knee bent
- Quadriceps stretch (emphasize the rectus femoris – 2 jt): “flamingoes” o Stand on contra leg, ipsi leg is bent making sure knee is facing down toward the ground; go into a PPT. Do not abd the leg or hyper ext at the hip.
- Hip flexors (illiospoas – 1 jt):
- Similar positioning like a front stance. Contra foot in front, ipsi foot in back, go into a PPT
- Substitution: APT, trunk rot., hip flex
- TFL (tensor fasciae latae): Origin iliac crest, insert IT (action: hip flex, MR, abd) o Cross leg (ipsi in back): Hip ext, add, SB away (push hip out lat) o Avoid trunk flex/ext
- Hamstring stretch: origin: tuberosity of ischium, linea aspera; insertion: tibia/fibula (action: flex knee, ext hip)
- Ext knee, flex hip
- Stabilize the L-spine and pelvis (no stabilization will result in T-spine flexion, PPT, hamstring origin gets closer to insertion à minimize the stretch) [2 legs in front, modified hurdles, standing]
- Adductors: Adductor brevis/longus/magnus/minimus, pectinius, gracilis, obturator externus (O: pubis, I: femur – except for gracilis on trochanteric fossa/tiba 2jt) o Butterflies (stretches adductors and MR): flex from hip not T-spine o Side lunge
- Splits (sitting) – keep neutral spine (R/L, Center)