Introduction Assessment

The assessment of length tension in muscle involves the use of clinical reasoning and interpretation of the subjective and objective assessment findings. These findings include:

- the referral pattern of pain;
- positional findings on observation;
- changes in active and passive range of motion;
- findings on palpation; and
- activation of the muscle and the flexibility of the muscle during the length tension assessment of the myofascial structures.

Differentiation must also be made in the tension and barrier that are palpated in order to determine whether this is due to the myofascial tissue or the neuromeningeal tissue. Conclusions are then based on these combined tests and the muscle is determined to be normal, hypertonic, shortened or lengthened.

The therapist may incorporate principles of neuromeningeal assessment in order to assess whether the tension and barrier present is due to the myofascial tissues or due to the neuromeningeal structures. Excellent resources are available on the assessment of neuromeningeal tissue, and readers are advised to refer to these for further information and more details. Therapists must have an appreciation for the uniqueness of our anatomy. All tension testing described in this book may have to be slightly altered to accommodate the examiner’s or the patient’s anatomy.

End feel

The different sensations imparted to the hand of the therapist at the extremes of the passive range of motion is termed the end feel. The end feel caused by changes in the myofascial system will be different from some of the end feels associated with a joint restriction.

Normal muscle at rest, and preferably with gravity eliminated, will feel soft. It will have the same feel as palpating raw steak or soft tofu. The length and tension will be as expected for the age of the patient. The contralateral muscle can be tested to confirm this. A normal muscle will contract with voluntary electromyographic ( EMG ) activity.

Hypertonic muscle has increased elastic and viscoelastic stiffness in the absence of contractile activity. Palpation of the hypertonic muscle will feel similar to palpating well done steak and it will have decreased length on testing. Muscle spasm is an abnormal muscle contraction and is often painful. The EMG activity is not under voluntary control. This strong contraction will limit movement significantly. A muscle spasm is velocity dependent. If the muscle is lengthened or moved quickly, an increase in muscle tone is evident.

Truly shortened muscle, or a muscle contracture, is often present post trauma and will feel gristly, tight and short on testing. The muscle contractile unit is shortened in the absence of EMG activity. When the muscle is lengthened or moved, the response is velocity independent. It does not matter if the movement is performed quickly or slowly, the response and length remains unchanged.

The therapist must recognize the different sensations imparted to the hands at the end of the available passive range of motion and gently sense the point at which the range of motion stops. It is with our palpation skills that we determine that it is in fact the muscle being tested that is felt to be tense and that is providing the resistance to the passive movement. Both the hand providing stabilization and the hand moving the body part must together sense the tension in the muscle and the barrier present.

Clinical reasoning

Length tension test findings may be unrelated to the palpation findings found in muscle at rest. As previously explained, the therapist must base their conclusions on a clinical reasoning approach to rule out other problems or tissues at fault. Length tension testing should preferably be performed in supine lying or prone lying to unload the muscle and neutralize the effect of gravity. This cannot always be done, however, and thus alternative test positions are also described.