- Observe a demonstration of static and PNF stretching techniques.
- Static
(Slow elongation of muscle, holding in stretched state for 10 to 30 seconds, then returning muscle to resting length. Repeat 4 times.)
- PNF (Proprioceptive neuromuscular facilitation)
(PNF techniques for stretching involve alternating isometric muscle action and passive elongation of the agonist.)
- hold/relax (also called contract/relax) involves six-second periods of isometric activation of the agonist, alternating with 10- to 30-second periods of passive elongation. Repeat four times.)
- slow reversal/hold/relax (concentric, then isometric activation of antagonist, followed by a six-second isometric activation of agonist, followed finally by 10- to 30-second passive elongation of agonist. Repeat four times.)
- Obtain and record baseline measures of the left and right hamstring muscle groups' lengths:
- Position your subject in supine with the hips and knees flexed and the pelvis tilted posteriorly so the back is flattened against the supporting surface.
- On the side of the muscle you wish to measure, position the hip in 90 degrees of flexion, then passively extend the knee to the end of its available range. Use the goniometer to measure this knee angle.
- Record in the table below the measurements of baseline hamstring (HS) length, in degrees of knee flexion, for the right and left limbs. Use the same table to record all hamstring length measurements for your group as you follow the lab procedure. Add your group's obserations to the Excel database that the class is constructing on the lab computer.
Subject ID | Sex
| Baseline HS length
(deg. of knee flexion)
| technique
(PNF, static)
| post-stretching HS length
(deg. of knee flexion)
| HS length post-30 min. delay
(deg. of knee flexion)
|
|---|
left | right | left | right | left | right | time | left | right | time
|
|---|
- Flip a coin, then perform the stretching techniques that you witnessed during the demonstration:
- Heads: perform a static stretching technique on the left, and a PNF technique of your choosing on the right.
- tails: perform a static stretching technique on the right, and a PNF technique of your choosing on the left.
Obtain and record measurements of post-stretching hamstring lengths, including the time that you record these measurements.
- Apply the static and PNF stretching techniques to at least four of the listed muscles. To help you develop an exercise that elongates the muscle's fibers, use the skin pencil to draw representative lines of application on your lab partner.
You need not limit yourself to techniques that require a therapist or partner to apply resistance. In some situations, you can can position the person so that gravity (the person's own body weight) provides the necessary force. The person can also activate antagonist muscles to elongate the target muscle.
- levator scapulae
- pectoralis major
- rhomboideus major and minor
- teres major
- upper trapezius
|
- pectoralis minor
- latissimus dorsi
- pronator teres
- extensor carpi radialis longus
|
|---|
- Consider a patient whose right upper extremity has been immobilized in a sling for three weeks, and whose glenohumeral range of motion is consequently limited in external rotation and abduction. Discuss and be prepared to demonstrate activities that incorporate either the static or PNF techniques into a home program to help this person regain glenohumeral range of motion.
At least one half hour after measuring and recording post-stretching hamstring lengths, repeat the measurements. Record these measurements in the table's post-30 min. delay column, note the time that you obtained them, and add your group's measurements to the Excel database.