Spasticity assessment includes both identifying which muscles or muscle groups are overactive, and also determining the effect of spasticity on all aspects of patient function, including mobility, employment, and activities of daily living. Physical and occupational therapists are critical members of the team approach to assessment of and treatment planning for spasticity, in both adults and children.
Abstract: An upper motor neuron syndrome often leads to the development of stereotypical patterns of deformity secondary to agonist muscle weakness, antagonist muscle spasticity and changes in the rheologic (stiffness) properties of spastic muscles. Identification of the spastic muscles that contribute to deformity across a joint allows therapeutic denervation to be implemented with the maximum likelihood of success. Identifying responsible muscles can be complex, since many muscles may cross the joint involved, and not all muscles with the potential to cause deformity will be spastic. Strategies including polyelectromyography and diagnostic blocks with local anesthetics can be used to test hypotheses regarding the deformity, providing information for more long-term denervation. In this review, we discuss frequently observed patterns of deformity associated with problematic spasticity, paresis, contracture, and impaired voluntary motor control.
The Adducted/Internally Rotated Shoulder: This patient with head injury demonstrates an adducted/internally rotated shoulder, flexed elbow, pronated forearm, bent wrist, and clenched fist. The patient also has a thumb-in-palm deformity. See Muscles.
The Flexed Elbow: This patient would often drive his fist into his throat because of severe elbow flexor spasticity. See Muscles.
The Pronated Forearm: Pronator quadratus and/or pronator teres may contribute to the pronated forearm deformity. See Muscles.
The Flexed Wrist: Severe spastic wrist flexion may sometimes lead to wrist subluxation and carpal tunnel syndrome. See Muscles.
The Clinched Fist: Two years after head injury, this patient illustrates a clenched fist with likely involvement of flexor digitorum sublimis. Flexor pollicis longus contributes to the thumb-in-palm deformity. See Muscles.
The Thumb-in-Palm Deformity: Eleven months after head injury, this patient illustrates thumb-in-palm deformity when he tries to open his hand. Dynamic EMG studies reveal that flexor pollicis longus, adductor pollicis, and the thenar muscles all contributed. A parallelogram type of finger electrogoniometer records motion across the third finger PIP joint. See Muscles.
Equinovarus: Varus posture may be seen in this patient from the anterior view. Excessive pressure typically occurs under the fifth metatarsal head. See Muscles.
Striatal Toe: Striatal toe (hitchhiker's great toe) caused by an overactive extensor hallucis longus. See Muscles.
Stiff Knee: Persistent knee extension of the "stiff knee," shown here with marked equinus. Note that the heel is not in contact with the foot pedal of the wheelchair. See Muscles.
Adducted Thighs: The "scissoring thighs" caused by spastic adductors produce a narrow base of support at the feet. See Muscles.
Key Points:
An upper motor neuron syndrome often produces stereotypic patterns of spasticity, paresis, contracture, and impaired voluntary motor control
Dynamic EMG studies and temporary diagnostic motor point blocks may be used to determine involvement of specific muscles
Muscles that often contribute to spastic adduction/internal rotation dysfunction of the shoulder include latissimus dorsi, teres major, the clavicular and sternal heads of pectoralis major, and subscapularis
In the flexed elbow, brachioradialis is spastic more often than biceps and brachialis
In the flexed wrist, carpal tunnel symptoms may occur secondary to compression of the median nerve
Flexion with radial deviation implicates flexor carpi radialis
In the clenched fist, if the PIP joints flex while the DIP joints remain extended, spasticity of FDS rather than FDP may be suspected
An intrinsic plus posture is a combined metacarpophalangeal flexion and PIP extension
The extrinsics may show spasticity, contracture, and some degree of volitional control
A patient may be spastic in only one or two muscle slips of either FDP or FDS
BTX is an excellent treatment for spasticity of the intrinsics because of their size and accessability
Spastic deformities of the lower limbs affect ambulation, bed positioning, sitting balance, chair level activities, transfers, and standing up
Equinovarus is the most common pathologic posture seen in the lower extremity
Equinovarus is a key deformity that can prevent even limited functional ambulation or unassisted transfers
Chemodenervation of EHL for striatal toe may reveal co-contraction of FHL, which also requires treatment
Overactivity of the hamstrings may indicate that knee stiffness is a defense against knee flexion collapse
Diagnostic motor point block may reveal whether weakening strategies are indicated for reducing knee stiffness
In the flexed knee, overactivity in the hamstrings is more often medial than lateral
Hamstring contracture is likely to occur from chronic overactivity
Adductor and hip flexor spasticity often coexist and may lead to pelvic obliquity
Complex hip and knee deformities may require a combination of neurolytic and chemodenervation agents
The role of chemodenervation and neurolytic agents necessarily becomes more limited when large numbers of muscles are involved
