Page 107 - Canine Lameness

5.4 Flexibility Testing 79

5.3.2 How to Interpret Joint Play Testing
Joint play testing determines the quality and quantity of joint surface gliding motion. In addition
to PROM testing, this information can be helpful in determining appropriate subsequent
diagnostic steps. For example, if shoulder flexion PROM is restricted with a capsular end feel, joint
play evaluation is indicated. If joint play in the medial direction is increased, disruption of the
medial shoulder stabilizers (i.e. the medial glenohumeral ligament and subscapularis muscle) is
suspected. If joint play in the cranial direction is abnormal, then pathology of the cranial structures
is suspected (e.g. the supraspinatus and biceps brachii muscles). A decrease in cranial glide may
indicate adaptive shortening of the biceps brachii muscle. On the other hand, an increase in cra-
nial glide may be noted with complete disruption of the biceps brachii muscle. These observations
may aid in selecting appropriate further diagnostics (e.g. sedated examination, MRI and/or ultra-
sound). This concept can be applied to any joint; knowledge of the common diseases affecting the
region helps dictate the most appropriate next diagnostic step. For example, if carpus extension
PROM end‐feel is elastic (i.e. normal) but the goniometric measurement is 215° (i.e. increased),
further evaluation with joint play testing is indicated. If the amount of glide is excessive, indicating
the carpal bones move beyond normal arthrokinematic motion, the observer may consider diag-
nostics for joint hypermobility (e.g. stress radiographs of the carpus).

5.4 Flexibility Testing

Flexibility testing is evaluation of muscle extensibility, in other words, the ability of the muscle to
stretch or passively elongate when an external manual force is applied. This flexibility testing is
generally combined with the myofascial exam (Chapter 6). Flexibility testing is an evaluation of
the passive extensibility of the contractile and connective tissue components of the muscle. The
purpose of flexibility testing is to determine whether flexibility is increased (e.g. indicating a rup-
ture), decreased (e.g. indicating a contracture), or normal and whether it is painful (e.g. indicating
inflammation). The answer to these questions may lead the tester to determine that further diag-
nostics of a specific muscle or muscle groups may be needed (e.g. ultrasound).
Flexibility testing is frequently confused with PROM testing. The difference between the two
tests lies in the positioning of the entire limb. For PROM, the goal is to put muscles on slack (to
isolate the joint), whereas for flexibility testing the goal is to stretch the muscles to isolate them.
Unfortunately, this is not possible for single‐joint muscles; however, the concept becomes clear
with the example of two‐joint muscles (Figure 5.4).
During the rehabilitation evaluation, flexibility testing is indicated in three instances: (i) PROM
is normal; (ii) PROM is limited with an elastic or muscle spasm end‐feel; or (iii) PROM is excessive
with an elastic or muscle spasm end‐feel.
If PROM is normal, flexibility testing is completed to determine if a muscle is contributing to the
lameness and if so, to what extent the muscle may be injured. An example is lameness due to acute
tenosynovitis of the biceps brachii muscle for which PROM of shoulder flexion may be normal (i.e.
shoulder flexion with the elbow flexed to place the biceps brachii on slack), but flexibility testing
of the biceps brachii (i.e. shoulder flexion with elbow extension placing the bicep brachii on taut)
is decreased and painful.
In the second instance, if PROM is limited with an elastic or muscle spasm end‐feel, flexibility
testing is completed to determine which muscle is contributing to the abnormal PROM. An exam-
ple is supraspinatus tendinopathy for which PROM shoulder flexion has an elastic end‐feel (the