Examination of the Child with Cereb ral Palsy

This article describes the balanced combination of medical history, detailed physical examination, functional assessment, imaging, observational gait analysis, computerized gait analysis, and assessment of patient and family goals that are necessary to prepare treatment plans and accurately assess outcomes of treatment of children with cerebral palsy.

Clinical evaluation

To prepare treatment plans and accurately assess outcomes of treatment of children with cerebral palsy (CP), a balanced combination of medical history, detailed physical examination, functional assessment, imaging, observational gait analysis, computerized gait analysis, and assessment of patient and family goals must be interpreted.

The medical history

The medical history should include a collection of information regarding birth history, developmental milestones, medical problems, surgical history, current physical therapy treatment, and current medication. Treatment plans depend on parent report of current functional walking level at home, school, and in the community, as well as other functional skills such as stair climbing, jumping, and running.

Birth history and other medical problems are important pieces of information for accurate diagnosis, future prognosis, treatment, and goal setting. Developmental milestones give information regarding the maturity of a skill such as walking and provide insight into the child’s future capacity. When considering surgical treatment, it is important to obtain the operative reports of previous surgeries to accurately assess current deformities and compensations. For example, iatrogenic weakness of the soleus muscle caused by heel cord lengthening may require a different treatment plan than primary soleus weakness.

Besides the medical history, the reason for referral and current surgical or treatment considerations are helpful. Complaints of pain, and behavior or learning issues assist the clinician in performing a good evaluation.

The medical history

Functional outcome measures

Current level of function can be assessed using tools such as the Functional Assessment Questionnaire (FAQ), the Pediatric Orthopaedic Society of North America (Pediatric) Outcomes Data Collection Instruments (PODCI), or the evaluative Functional Mobility Scale (FMS). The FAQ is a validated 10-level parent report of ambulation. A child who is typically able to keep up with peers is scored at level 10; the scale decreases with decreasing ability for community ambulation. A companion FAQ-22 can be used to report other functional skills related to ambulation such as stair climbing, running, and encountering obstacles in the community such as curbs. The PODCI is also a validated parent report instrument designed to be used across ages and musculoskeletal disorders to assess functional health outcomes. It measures outcomes that can be affected by orthopedic treatment, and includes measures of upper and lower extremity motor skills, relief of pain, and restoration of activity. Correlations have been found between the FAQ, PODCI, and gait measures in children. When used in conjunction with gait data, they provide a more complete survey of change. The FMS is an evaluative measure of functional mobility in children with CP aged 4 to 18 years. It quantifies functional mobility at both the activity level and participation domains of the International Classification of Functioning, Disability and Health. A unique feature of the FMS is reporting assistive device use in various environmental settings. The FMS has been shown to have adequate sensitivity to measure change after orthopedic intervention in children with CP.

Physical examination

The standard physical assessment form used in the motion analysis laboratory at Gillette Children’s Specialty Healthcare provides a useful reference to a comprehensive physical examination ( Fig. 1 ).

The physical examination can be separated into 7 broad categories:

1.

Strength and selective motor control of isolated muscle groups
2.

Degree and type of muscle tone
3.

Degree of static muscle and joint contracture
4.

Torsional and other bone deformities
5.

Fixed and mobile foot deformities
6.

Balance, equilibrium responses, and standing posture
7.

Gait by observation.

Of course, physical examination is crucial, but its limitations in developing a plan for intervention must be recognized. The information collected during a physical examination is based on static responses, whereas functional activities, such as walking, are dynamic. Gait analysis data cannot be predicted by any combination of physical examination measurements either passive or active; however, there is a moderate correlation between time and distance parameters and strength and selectivity measures. The independence of gait analysis and physical examination measures supports the notion that each provides information that is important in the delineation of problems of children with CP. Numerous investigators have reported the lack of correlation between crouch gait and hamstring contracture identified by popliteal angle, for example. The method of assessment, the skill of the examiner, and the participation of the child can all affect the validity and reliability of the examination. The degree of tone can change with the position of the child, whether they are moving or at rest, the level of excitement or irritability, or the time or day of the assessment. Objective evaluation of muscle strength is difficult in small children and children with neurologic impairments. In addition, motor control and the assessment of movement dysfunction are subjective and rely heavily on the experience and expertise of the examiner.

Muscle strength

Strength evaluation is necessary to assess appropriateness for interventions such as selective dorsal rhizotomy or lower extremity surgery. Children with CP are weak. Motor function and strength are directly related. Manual muscle testing (MMT) using the Kendall scale is the typical method for measuring muscle strength in children with CP. Isometric assessment with a dynamometer is becoming more common in the clinic, and is often used in research and outcome studies. Isokinetic evaluations are used when evaluating strength throughout the range of motion (ROM).

The 5-point Kendall scale provides an easy and quick way to assess a child for significant weakness or muscle imbalance, and requires only a table and standardized positioning. However; it does rely heavily on the examiner’s judgment, experience, the amount of force generated by the examiner, and the accuracy of the positioning of the patient. Small yet clinically significant differences in strength may not be detected using this method. It is subjective and prone to examiner bias. However, under strict evaluation protocols, this method is useful. For children who are less than the age of 5 years, and who cannot follow complex directions for maximal force production, the MMT method, as well as any other method of strength assessment, should be considered a screening tool at best.

Because of the wide variation that is seen with manual muscle assessment of isometric strength, the use of a hand-held dynamometry (HHD) has increased in the clinic and in research protocols to better quantify strength variation. The HHD approach has been shown to be a valid and reliable tool to measure isometric strength in patients with brain lesions and in children with CP. However, it has an upper limit, and exceeds that limit when used with stronger patients. Strength profiles for children with CP and normative data for young children have been published. Validity of this examination still depends on appropriate positioning, whether stabilization is used, and the experience of the tester. Normalization is required for body weight and lever length for strength comparisons.

Isokinetic strength assessment is used to measure torque generated continuously through an arc of movement. The length of time required for this assessment, the expense and lack of portability of the equipment, and the difficulties young children have complying with this test modality have limited the incorporation of isokinetic strength testing in the pediatric clinical setting.

Selective motor control

Impaired ability to isolate and control movements confounds strength assessment and contributes to ambulatory and functional motor deficits. Assessment of selective motor control involves isolating movements on request, appropriate timing, and maximal voluntary contraction without overflow movement. A typical scale for muscle selectivity reports 3 grades of control: 0, no ability; 1, partial ability; and 2, complete ability to isolate movement. The detailed definitions and descriptions for the lower extremity muscles groups assist in accurately describing a patient’s motor control and are always reported together with strength ( Table 1 ).

Table 1

Selective motor control grading scale description

Definitions of Selective Motor Control
Hip Flexion
Position: patient seated supported or unsupported with hips at a 90° angle, legs over the side of the table. Arms folded across chest or resting in lap (not on the able or hanging on to the edge)
2: hip flexion in a superior direction without evidence of adduction, medial or lateral rotation, or trunk extension
1: hip flexion associated with adduction, medial or lateral rotation, or trunk extension that is not obligatory but occurs in conjunction with the desired motion through at least a portion of the ROM
0: hip flexion that occurs only with obligatory knee flexion, ankle dorsiflexion, and adduction
Hip Extension (Hamstrings plus Gluteus Maximus)
Position: patient lying prone, head resting on pillow (prone on elbows not allowed). Knees in maximum possible extension. Pelvis stabilized as necessary
2: hip extension in a superior direction without evidence of medial or lateral rotation, trunk extension, or abduction
1: hip extension associated with medial or lateral rotation, trunk extension, or abduction that is not obligatory but occurs in conjunction with the desired motion through at least a. portion of the ROM
0: hip extension that occurs only with obligatory trunk extension, arm extension, or neck extension. May also include medial or lateral rotation, or abduction
Hip Extension (Gluteus Maximus)
Position: patient lying prone, head resting on pillow (prone on elbows not allowed). Knees in 90° or more flexion, hips in neutral extension, pelvis flat on table. Pelvis stabilized as necessary
2: hip extension in a superior direction without evidence of medial or lateral rotation, knee extension, or hip abduction
1: hip extension associated with knee extension, trunk extension, medial or lateral rotation, or abduction that is not obligatory but occurs in conjunction with the desired motion through at least a portion of the ROM
0: hip extension that occurs only with obligatory knee extension, trunk extension, medial or lateral rotation, or abduction
Hip Abduction
Position: side-lying, the hip in neutral or slight hip extension, neutral medial or lateral rotation, knee in maximum possible extension. Pelvis stabilized as necessary
2: hip abduction in a superior direction without evidence of medial or lateral rotation or hip flexion
1: hip abduction in a superior direction associated with hip flexion, or medial or lateral rotation that is not obligatory but occurs in conjunction with the desired motion through at least a portion of the ROM
0: hip abduction that occurs with obligatory hip flexion, or medial or lateral rotation
Hip Adduction
Position: side-lying body in straight line with legs, the hip in neutral or slight hip extension, neutral medial or lateral rotation, knee in maximum possible extension, opposite limb supported in alight abduction. Pelvis stabilized as necessary
2: hip adduction in a superior direction without evidence of hip flexion, medial or lateral rotation, or tilting/rotation of the pelvis
1: hip adduction in a superior direction associated with hip flexion, or medial or lateral rotation, pelvis tilting/rotation that is not obligatory but occurs in conjunction with the desired motion through at least a portion of the ROM
0: hip adduction that occurs with obligatory hip flexion, or medial or lateral rotation
Knee Extension
Position: patient seated supported or unsupported with hips at a 90° angle, knees at 90° angle resting over the side of the table. Thigh stabilized as necessary
2: knee extension in a superior direction, without evidence of hip or trunk extension, medial or lateral rotation of the thigh or hip flexion
1: knee extension associated with hip or trunk extension, hip flexion, or medial or lateral rotation of the thigh that is not obligatory but occurs in conjunction with the desired motion through at least a portion of the ROM
0: knee extension that occurs with obligatory hip or trunk extension, hip flexion, or medial or lateral rotation of the thigh
Knee Flexion
Position: patient lying prone, head resting on pillow (prone on elbows not allowed). Knees in maximum possible extension. Pelvis and thigh stabilized as necessary
2: knee flexion in a superior direction without evidence of hip flexion, medial or lateral thigh rotation, or tilting, rotation of the pelvis, or ankle plantarflexion
1: knee flexion associated with a pelvic rise, hip flexion, medial or lateral rotation of the thigh, or ankle plantarflexion that is not obligatory but occurs in conjunction with the desired motion through at least a portion of the ROM
0: knee flexion that occurs with obligatory hip flexion, pelvic tilting or rotation, medial or lateral rotation of the thigh or ankle plantarflexion
Ankle Dorsiflexion (Anterior Tibialis)
Position: patient seated supported or unsupported with hips at a 90° angle, knees in extension (flexion may be allowed to achieve a range of dorsiflexion). Lower leg supported. Thigh stabilized as necessary
2: ankle dorsiflexion and inversion without evidence of increased knee flexion, subtalar eversion, or extension of the great toe
1: ankle dorsiflexion and inversion associated with increased knee flexion, subtalar eversion, or extension of the great toe that is not obligatory but occurs in conjunction with the desired motion through at least a portion of the ROM
0: ankle dorsiflexion and inversion that occurs with obligatory knee flexion, subtalar eversion, or extension of the great toe
Ankle Plantarflexion (Soleus)
Position: patient lying prone, head resting on pillow (prone on elbows not allowed). Knees in 90° of flexion. Lower leg stabilized proximal to the ankle as necessary. Ankle in neutral plantarflexion/dorsiflexion position
2: ankle plantarflexion in a superior direction without evidence of knee extension, subtalar inversion, eversion, or toe flexion
1: ankle plantarflexion associated with knee extension, subtalar inversion, eversion, or toe flexion that is not obligatory but occurs in conjunction with the desired motion through at least a portion of the ROM
0: ankle plantarflexion that occurs with obligatory knee extension, subtalar inversion, eversion, or toe flexion
Ankle Plantarflexion (Gastrocnemius)
Position: patient lying prone, head resting on pillow (prone on elbows not allowed). Knees in maximum extension, foot projecting over the end of the table. Lower leg stabilized proximal to the ankle as necessary. Ankle in neutral plantarflexion/dorsiflexion position
2: ankle plantarflexion in a superior direction without evidence of subtalar inversion, eversion, or toe flexion
1: ankle plantarflexion associated with subtalar inversion, eversion, or toe flexion that is not obligatory but occurs in conjunction with the desired motion through at least a portion of the ROM
0: ankle plantarflexion that occurs with obligatory subtalar inversion, eversion, or toe flexion
Ankle Inversion (Posterior Tibialis)
Position: patient seated supported or unsupported with hips at a 90° angle, thigh in lateral rotation, knees in flexion with lower leg stabilized proximal to the ankle. Ankle in neutral plantar/dorsiflexion
2: inversion at the STJ with plantarflexion of the ankle without evidence of toe flexion
1: inversion at the STJ with plantarflexion of the ankle associated with toe flexion that is not obligatory but occurs in conjunction with the desired motion through at least a portion of the ROM
0: inversion at the STJ with plantarflexion of the ankle that occurs with obligatory and forceful toe flexion
Ankle Eversion (Peroneus Brevis plus Peroneus Longus)
Position: patient seated supported or unsupported with hips at a 90° angle, thigh in medial rotation, knees in flexion with lower leg stabilized proximal to the ankle. Ankle in neutral plantar/dorsiflexion
2: eversion at the STJ with plantarflexion of the ankle without evidence of toe flexion. If head of first metatarsal is depressed action of the peroneus longus is indicated
1: eversion at the STJ with plantarflexion of the ankle associated with toe flexion that is not obligatory but occurs in conjunction with the desired motion through at least a portion of the ROM
0: eversion at the STJ with plantarflexion of the ankle that occurs with obligatory and forceful toe flexion
Ankle Eversion (Peroneus Tertius)
Position: patient seated supported or unsupported with hips at a 90° angle, knees in flexion with lower leg stabilized proximal to the ankle. Ankle in neutral plantar/dorsiflexion
2: eversion at the STJ with dorsiflexion of the ankle and 2- to 5-toe extension
1: not applicable
0: not applicable (peroneus tertius and extensor digitorum longus are anatomically combined; the 2 muscles always act together)
Great Toe Extension (Extensor Hallucis Longus)
Position: patient seated supported or unsupported with hips at a 90° angle, knees in flexion with lower leg supported. Ankle in neutral plantar/dorsiflexion
2: extension of the metatarsophalangeal joint of the great toe without evidence of knee flexion or ankle dorsiflexion
1: extension of the metatarsophalangeal joint of the great toe associated with knee flexion or ankle dorsiflexion that is not obligatory but occurs in conjunction with the desired motion through at least a portion of the ROM
0: extension of the metatarsophalangeal joint of the great toe with obligatory knee flexion, or ankle dorsiflexion
Great Toe Flexion (Flexor Hallucis Longus)
Position: patient seated supported or unsupported with hips at a 90° angle, knees in maximum extension with lower leg supported. Ankle in neutral plantar/dorsiflexion
2: flexion of the metatarsophalangeal joint of the great toe without evidence of knee extension or ankle plantarflexion
1: flexion of the metatarsophalangeal joint of the great toe associated with knee extension or ankle plantarflexion that is not obligatory but occurs in conjunction with the desired motion through at least a portion of the ROM
0: flexion of the metatarsophalangeal joint of the great toe with obligatory knee extension, or ankle plantarflexion

From Gage JR, Schwartz MH, Koop SE, et al, editors. The identification and treatment of gait problems in cerebral palsy. London: Mac Keith Press; 2009. p. 187; with permission.

During static physical examination, a child with hemiplegia may not be able to actively dorsiflex the ankle on the involved side without a mass flexion pattern including hip and knee flexion. On examination muscle strength of 3/5 (3 out of 5), with a selectivity grade of 0/2 (0 out of 2) is identified. While walking this child may have difficulty with clearance of their foot in early swing phase because of the inability to perform dorsiflexion with the hip in extension. However, in midswing, dorsiflexion with inversion could occur because of the child’s inability to regulate the pull of the anterior tibialis and the extensor digitorum longus. In this situation, adequate dorsiflexion occurs, but the timing is late and the motion is not controlled. No surgical treatment would be able to address the problems of timing and balance. An orthotic may be the more appropriate recommendation.

Muscle tone assessment

Tone is the resistance to passive stretch while a person is attempting to maintain a relaxed state of muscle activity. Hypertonia has been defined as abnormally increased resistance to an externally imposed movement about a joint. It can be caused by spasticity, dystonia, rigidity, or a combination of these features. Resting muscle tone can be influenced by the degree of cooperation, apprehension, or excitement present in the patient as well as the position during the assessment. Time spent playing or talking with the child before and during the examination often helps with the accuracy of the examination. Muscle tone assessment on different occasions by different practitioners may be necessary to accurately characterize the nature of the child’s muscle tone. Standardization within a facility for testing positions and the use of a grading scale are imperative. Sanger and colleagues recommend this process: start by palpating the muscle in question to determine if there is a muscle contracture at rest. Next, move the limb slowly to assess the available passive ROM. The limb can then be moved through the available range at different speeds to assess the presence or absence of a catch and how this catch varies with a variety of speeds. Next, change the direction of motion of the joint at various speeds and assess how the resistance (including timing) varies. Last, observe the limb/joint while asking the patient to move the same joint on the contralateral side. Observe and document any involuntary movement or a change in the resistance to movement on the side being assessed. By using a standard process for evaluation, the consistency and completeness of tone abnormality documentation improve.

Spastic (compared with dystonic) hypertonia causes an increase in the resistance felt at higher speeds of passive movement. Resistance to externally imposed movement rises rapidly above a speed threshold (spastic catch). The Ashworth scale, modified Ashworth scale, Tardieu scale, and an isokinetic dynamometer in conjunction with surface electromyography are methods used to assess severity of spastic hypertonia.

On the other hand, dystonic hypertonia shows an increase in muscle activity when at rest, has a tendency to return to a fixed posture, increases resistance with movement of the contralateral limb, and changes with a change in behavior or posture. There are also involuntary sustained or intermittent muscle contractions causing twisting and repetitive movements, abnormal postures, or both. The Hypertonia Assessment Tool (HAT) is a tool developed to distinguish between spasticity, dystonia, and rigidity in the pediatric clinical setting ( Fig. 2 ). The reliability and validity for spasticity and rigidity is good, but only moderate for dystonia and mixed tone. The Barry Albright Dystonia (BAD) scale, a 5-point ordinal scale, is another measure of generalized dystonia. Mixed tone is often identified with a combination of both types of hypertonicity in the same patient. Mixed tone is more difficult to diagnosis and quantify than pure spasticity. However, in children with CP, it is important to assess the degree of mixed tone present, because the outcome of surgery may be less predictable.