Front Matter

Chapter 13 Evaluation and Rehabilitation Options for Orthopedic Disorders of the Canine Thoracic Limb 347

stance (isometric), and push‐up (eccentric) to
observe if increasing muscle tension increases
pain. Close observation of pain response during
this test is essential. Passive muscle extensibility is
tested as it helps differentiate whether contractile
or elastic components are painful. For example,
beginning the biceps stretch with the gleno-
humeral joint in neutral and very slowly stretch-
ing the biceps allows the therapist to note quality
of extensibility and onset of pain response.
Further assessment with palpation is then needed
to determine the precise location of injury.
Treatment of strain injuries must follow a pre-
cise course of treatment to promote tissue healing
and prevent muscle cells from adaptive shorten-
ing, predisposing the patient to chronic tendino-
sis injuries. Acute injuries require immediate
resolution of edema with modalities and pain‐
free active contractions to prevent collagen mis-
alignment and disuse atrophy. The subacute
phase of healing requires pain‐free increases in
strength training intensity while preventing

re‐exacerbation of the primary injury, which is best

achieved with concentric contractions. The chronic

phase of healing demands return of strength

using eccentric contractions, which promote tis-

sue extensibility while producing the highest

loads through the muscle tissues (Verrall et al.,

2011). Throughout the course of treatment, reas-

sessment is required to determine whether tissues

are following a normal course of healing. Patients

that do not follow a normal course of healing are

reassessed to determine the correct rehabilitation

diagnosis and/or the treatment plan is modified

to promote healing and to avoid re‐exacerbation.

The underlying mechanism of chronic mus-

cle extensibility injuries is adaptive cellular

changes in both contractile and elastic fibers

that histologically have little or no evidence of

inflammation (Khan et al., 1999). Unlike tend-

initis injuries, where the acute treatment regime

goal is to decrease inflammation, treatment of

chronic adaptive shortening requires instigating

an inflammatory response to coax the tissues

Case Study 13.1 Acute‐on‐chronic biceps tendinopathy

Signalment: 10‐y.o. F/S Labrador Retriever.

Diagnosis: Radiographic right glenohumeral joint OA.

Subjective findings: Acute onset of right thoracic

limb (RTL) head‐bobbing lameness 3/5, significantly

worse upon waking, improves throughout the day,

but worse after play and 30‐minute walks. Five‐year

history of intermittent RTL lameness.

Objective findings: Posture: right scapula craniodorsal

positioning on thorax.

Function: refusal to maintain sternal position,

lameness increases down stairs.

Strength: <3/5 (poor) strength RTL isometric

contraction.

Gait: RTL decreased stride length end of stance

phase.

Palpation: heat and pain on medial glenohumeral

joint line, discomfort on supraspinatus muscle belly,

pain at origin of biceps brachii tendon, pain and spasm

in latissimus dorsi and teres major.

Range of motion: glenohumeral joint flexion 70

degrees with empty end‐feel, extension 150 degrees

with hard capsular end‐feel, abduction 40 degrees

with hard capsular end‐feel.

Flexibility: biceps decreased flexibility and pain,

supraspinatus decreased flexibility, omotransversarius

decreased flexibility.

Joint play: 2/6 cranial glide of humerus on glenoid

fossa.

Assessment: From a rehabilitation perspective, the

primary limiting factors to highest level of function

include right biceps brachii pain and decreased

flexibility with compensatory supraspinatus muscle

overuse and shortening. Chronicity of injury leads

therapist to suspect this is an acute‐on‐chronic biceps

tendinopathy with adaptive shortening of the cranial

joint capsule exacerbating the underlying gleno-

humeral joint OA with compensatory overuse pain

and tightness in the supraspinatus, latissimus dorsi,

and teres major.

Plan of care:

Acute phase:

(1) Decrease edema: laser 4.0 J/cm^2 to target tis-

sues including glenohumeral joint and biceps

tendon.

(2) Decrease acute pain: TENS 5 Hz, 160 μs pulse

width, 20 minutes, nerve roots of musculocu-

taneous nerve (C6, C7, C8).

(3) Begin reversal of adaptive shortening of gleno-

humeral joint capsule: grade I–IV cranial joint

glides.

(4) Begin reversal of decreased extensibility of

muscle tissue: soft tissue mobilization and

stretching.

(5) Implement home exercise program: slow

walking daily for 10 minutes followed by

biceps and supraspinatus pain‐free stretches

held for 30 seconds (Table 13.3).