Differential Diagnosis of Torticollis: A Case Report : Pediatric Physical Therapy

Secondary Logo

Journal Logo

Case Report

Differential Diagnosis of Torticollis: A Case Report

Gray, Gaelan Mahina DPT; Tasso, Kay H. PT, PhD, PCS

Author Information
doi: 10.1097/PEP.0b013e3181beca44
  • Free


Torticollis is a general term used to describe a unilateral shortening or fibrosis of the sternocleiodomastoid (SCM) muscle causing lateral inclination of the head toward the tightened side. Torticollis may present at birth or shortly thereafter.1–8 The incidence of torticollis is 1 in every 250 live births,6 with plagiocephaly and developmental hip dysplasia as concomitant impairments.3,4,6,8–10

Torticollis can originate from a variety of primary etiologies such as ocular, osseous, or neurological abnormalities or because of congenital muscular or postural positioning.1,8,9,11 As a result, the initial medical evaluation of any patient with torticollis should involve a thorough history and physical examination to rule out other diagnoses and should include a thorough neurological assessment, plain radiographs, and ophthalmological consultation.3,4,6,8

The etiology of congenital muscular torticollis (CMT) is uncertain. However, research indicates that a vascular insult to the SCM muscle causes formation of fibrotic tissue that results in muscle shortening.1–8,10 Early detection of torticollis and initiation of physical therapy (PT) is associated with improved outcomes and a lower incidence of surgical lengthening of the SCM.3 If significant limitations in cervical rotation remain after 6 months of a manual stretching program, surgical treatment is recommended.12

The clinical signs of CMT include (1) unilateral fibrosis or shortening of the SCM muscle; (2) lateral flexion of the head, and deviation of the chin to the contralateral side with noted loss of active and passive range of motion of the cervical spine; (3) palpable mass or tumor in the SCM muscle during the first 3 months of life followed by restricted range of motion and fixed torticollis posturing due to a fixed or restricted SCM muscle; (4) craniomorphological changes (referred to as plagiocephaly) including flattened parietal-occipital area, an anteriorly shifted ear contralateral to the shortened SCM muscle with frontal flattening on the ipsilateral side; and (5) compensatory postures in the cervical and thoracic spines, trunk, and extremities including shoulder elevation and side bending of the trunk on the impaired side.4,8

This case report describes the differential diagnosis of CMT, its associated clinical signs, and the clinical outcomes of PT intervention for an infant who also had hydrocephalus.

Differential Diagnosis

Differential diagnosis of the cause of a patient’s torticollis is critical for the physical therapist not only to confirm that the correct diagnosis has been made but also to ensure that the patient is appropriate for PT. The therapist can assist the referring physician in determining the etiology of the torticollis by providing information regarding what the PT examination process reveals. Once the correct diagnosis has been determined, an individualized PT plan of care can be established. Thus, it is important for the therapist to actively participate in the process of differential diagnosis of torticollis.

CMT Versus Congenital Postural Torticollis (CPT).

A patient with CPT has signs resembling CMT but without a palpable mass or contracted SCM. Patients with CPT have a decreased ability to actively rotate or laterally flex their head to end range but have normal passive cervical range of motion. The SCM muscle feels taut but pliable, not fixed or restricted, and with 2 or 3 attempts at stretching into cervical rotation and lateral flexion, normal passive end range of motion can be achieved. The infant will be unable to consistently keep the head in midline. Compared with a fixed head tilt seen in CMT, infants with CPT intermittently tilt the head. As a result, the head tilt will fluctuate with a change in position.4 Infants with a persistent preferred head position without evidence of morphologic changes in the SCM may develop CPT. During the first 5 months of life, CPT can be caused by deformational plagiocephaly at birth and/or one-sided positioning after birth.12 The infant described in this case study presented with apparent tension and restriction in the left SCM muscle, limitations in passive cervical side bending to the right and rotation to the left (Table 1), and a fixed head tilt in the supine, prone, and supported sitting positions, so CPT was ruled out.

Cervical Range of Motion Measurements

Ocular Abnormalities.

Ocular abnormalities may also be a cause of torticollis. Infants with ocular torticollis tend to present with the postural signs of torticollis without restrictions in cervical range of motion.3,13 Patients with impairment of extraocular muscles in 1 eye tend to adopt an abnormal head posture, specifically a tilt or turn of the head, to achieve a clear binocular view and to avoid diplopia.6,13 Although many ophthalmic conditions may produce a compensatory change in head posture, paralytic and restrictive disorders of ocular movement, nystagmus, and defects of the visual field tend to be the most prevalent.13 In particular, paresis of the superior oblique muscle could result in head tilt away from the side of impairment and is noted as the most common source of ocular torticollis.3 Ocular torticollis tends to occur later than nonocular torticollis, after the infant has developed head control and binocular vision.13 Further, ocular abnormalities are frequently inherited. Therefore, obtaining the family history for a child with torticollis is essential to the process of differential diagnosis for torticollis.13 The infant in this case had no signs of nystagmus or visual field deficits. Instead, the infant presented with restrictions in passive cervical range of motion, which are consistent with CMT rather than ocular torticollis.

Osseous Abnormalities.

Osseous abnormalities can also cause torticollis. These abnormalities include C1–C2 subluxation, also referred to as Grisel syndrome.6,14 In the case of Grisel syndrome, an infection that causes periligamentous inflammation that results in ligamentous laxity resulting in subluxation of the atlantoaxial joint and, ultimately, torticollis.14,15 Common infections include upper respiratory infection, otitis, pharyngitis, sinusitis, cervical adenitis, and retropharyngeal abscess. Any inflammatory process in the upper cervical region that irritates the cervical muscles, nerves, or vertebrae, including trauma and surgical intervention, can produce reflex spasm resulting in torticollis.14 Computed axial tomography can be used to radiologically diagnose atlantoaxial subluxation.15 The patient in this case did not present with an underlying head or neck infection or any previous surgical procedure, and hence the physician did not request a computed axial tomography scan. Osseous abnormalities were ruled out as a possible cause of this patient’s torticollis.

Neurological Abnormalities.

Neurological abnormalities such as a posterior fossa tumor, syringomyelia, and a spinal cord tumor can cause torticollis.6,9 Associated symptoms may include headache, nausea, vomiting, and positive neurological signs.9 A neurological screen was performed during the initial PT evaluation of this patient using items from the Neonatal Behavioral Assessment Scale.16 In particular, the infant’s interactive ability, motor behavior, behavioral state organization, and physiologic organization were assessed.16 The interactive ability included response to auditory and visual animate and inanimate stimuli, consolability, and alertness. His motor ability was assessed by observation of hand-to-mouth activity, head control during pull-to-sit, response to a cloth over his face, and Landau and symmetrical tonic neck reflexes. The infant’s ability to cycle through the various states and to habituate to auditory, visual, and tactile stimuli demonstrated his behavioral state.16 The infant in this case did not present with any abnormal interactive, motor, or organizational behaviors. However, he had an abnormally broad forehead and significant gross motor delays. For these reasons, the pediatrician consulted a neurologist and requested a magnetic resonance imaging study to evaluate neurologic causes for the broad head and developmental delay. Magnetic resonance imaging results revealed the presence of hydrocephalus with no increase in intracranial pressure. The cause of the hydrocephalus was not determined. Although neurological abnormalities were not considered the most likely cause of this patient’s torticollis, the infant was monitored by a neurologist to check for any changes in his hydrocephalus.

Description of Case

A 4-month-old male infant was referred by his pediatrician for physical therapy evaluation and treatment for torticollis. The patient presented to an outpatient pediatric clinic with an asymmetrical head position and a left cervical head tilt (Fig. 1). The hydrocephalus was not yet diagnosed. The patient was born at 38 weeks by cesarean section because of breech presentation with the head turned to the right. Birth weight was 6 pounds 10 ounces. Medical history was unremarkable for vision, hearing, feeding, or reflux problems.

Fig. 1.:
Child’s posture at initial presentation to physical therapy.

The patient’s mother first noticed an asymmetrical head position at birth when the infant preferred to breastfeed on the right side. She notified the pediatrician of the infant’s preference and stated that the amount of intake of breast milk was sufficient. The pediatrician first noticed the flatness of his head and then the asymmetrical head position when he was 2½ months old. The patient’s mother reported that the flatness and the asymmetrical head position had increased since birth, and she had become quite concerned about the infant’s condition. She stated that he spent about 5 minutes in the prone position 2 to 5 times per day and averaged 1 hour per day in his car seat.

The PT examination was performed, and gross motor development was screened using the Alberta Infant Motor Scale (AIMS). The AIMS has been shown to have high levels of intrarater and interrater reliability when used on infants from birth to 18 months of age.17 The patient scored in the 10th percentile based on his chronological age. Passive cervical range of motion was measured using the cervical protractor.11 The patient had 45 degrees of passive cervical rotation range of motion on the left and 95 degrees on the right (Table 1). Passive cervical side bending was 55 degrees on the left and 30 degrees on the right. Limited extensibility was noted in the left SCM, upper trapezius, levator scapulae, and paraspinal muscles. Cranial asymmetries were noted when viewed from above with right posterior flattening of the skull and left forehead bossing. The right ear was more anterior than the left. Facial features were symmetrical.

The infant consistently positioned his head and neck in an asymmetrical posture when in prone, supine, supported sitting, and supported standing positions. Postural asymmetries noted included rotation of the chin to the right, the left shoulder elevated higher than the right, and trunk side bending to the right. Limitations of active left cervical rotation were also noted in prone, supine, and sitting positions. When in a prone position, he was able to lift his head only slightly off the supporting surface. In the prone position, he could turn his head to the right 90 degrees and to the left 15 degrees.

In the supine position with his head placed in midline, he was able to follow an object at eye level with the trunk stabilized by rotating his head to the right 90 degrees and to the left 15 degrees. When pulled slowly to the sitting position from the supine position, he did not activate his arms to assist in the transition.

The infant could not maintain his head in midline when placed in the supported sitting position. When supported in sitting, he demonstrated 90 degrees of cervical rotation to the right but only 15 degrees to the left.

Upper extremity and lower extremity passive range of motion was within normal limits. Infants with CMT have a higher incidence of developmental dysplasia of the hip.6 The infant was screened using the Ortolani maneuver, the results of which was negative. Physical therapists commonly use either the Ortolani or the Barlow maneuver to screen for developmental dysplasia of the hip.18 Although research indicates the Ortolani maneuver has poor reliability, there is no agreement on a more efficacious screening tool.19 Muscle tone was within normal limits.

Palpation of the left SCM muscle body revealed an increase in tension when placed on a slight stretch. Although there was no palpable mass in the left SCM muscle, there was a tight band in the SCM muscle, and soft tissue restrictions were noted. Tight bands of muscle were palpable in the left upper trapezius, left levator scapulae, and left paraspinal muscles. Cervical skin folds were asymmetrical with increased skin folds and redness on the left side of the neck. Passive stretching of lateral cervical flexion seemed to cause pain because of tension on the skin.

On the basis of the examination and evaluation, literature review, and differential diagnosis, the patient was found positive for a diagnosis of CMT. CMT is consistent with musculoskeletal pattern 4B from The Guide to Physical Therapy Practice.20

Plan of Care

The patient’s CMT resulted in decreased active and passive range of motion in right cervical side bending and rotation to the left and decreased strength of the cervical musculature. These primary impairments seem to have led to secondary impairments in the cervical and thoracic spine, trunk, and upper extremities because of postural compensations. The impairments were accompanied by the following functional limitations: (1) inability to track objects from midline to the left and right in supine, prone, and sitting positions; (2) inability to roll from supine to prone and prone to supine; (3) inability to maintain his head in midline while prone on his elbows; and (4) inability to sit independently with his head in midline.

The goals for PT intervention were to (1) track an object from midline to the left 90 degrees in the supine, prone, and sitting positions; (2) track an object from left to right and right to left in an arc of 180 degrees in the supine, prone, and sitting positions; (3) roll to either side independently and equally to retrieve a toy; (4) roll from supine to prone and prone to supine independently and equally using his head and upper extremities appropriately; (5) assume prone on elbows with his head in midline and lifted against gravity 90 degrees with equal weight-bearing through his trunk and without any postural compensations; and (6) sit independently with his head in midline with equal weight-bearing through his buttocks without any postural compensations or loss of balance while playing with upper extremities. These goals were designed to assist with midline head positioning without any postural compensations during all gross motor skills such as sitting, crawling, pulling to stand, cruising, and walking.

The patient had good family support. In addition, he tolerated handling well and interacted well in his environment. However, because of his hydrocephalus and other postural deviations, his prognosis was only fair.

Many factors must be weighed to determine the most efficient and effective treatment plan for an infant with CMT. The age of the infant; severity of the torticollis; the presence of plagiocephaly, neuromuscular, or orthopedic conditions; and the abilities of the parents to perform the exercises and repositioning procedures.2,3,11 In general, intervention for CMT should focus on normalizing the range of motion in the cervical region, treating SCM imbalances, and minimizing asymmetry in spontaneous positional and movement preferences.2,11,12

Description of Intervention

In general, PT seems to be the most beneficial when applied between 2 and 8 months of age.12 This patient was seen once a week for 45 to 60 minutes per treatment until 11 months of age. During the 6 months of PT, intervention consisted of passive cervical side bending and stretching techniques, cervical strengthening techniques, and neuromuscular facilitation of gross motor skills encouraging symmetry of movement and midline head position.

Gentle manual cervical stretching techniques into right cervical side bending and left cervical rotation were performed throughout his PT. Initially, the infant could only tolerate stretching for 30 seconds while distracted from the discomfort by engaging him in an entertaining activity. As the therapy progressed, he was able to tolerate prolonged stretches of 2 to 3 minutes each with a low intensity to prevent trauma to the collagen structures and without provoking pain or crying and thereby improving the range of motion.12 Low-intensity passive cervical stretching without provoking pain was used to prevent microtrauma of the soft tissue that can arise and lead to more fibrosis and decrease in range of motion.11 Active right cervical side bending and left rotation were facilitated for strengthening.

Neuromuscular facilitation techniques were used to assist the patient in developing age-appropriate gross motor skills while encouraging midline head position. Facilitation techniques were used to encourage the patient to assume and maintain a prone on elbows position with his head up to 90 degrees and in midline with his trunk. Initially, the infant could only tolerate 10 to 30 seconds but was able to progress to 2 to 3 minutes at a time. The patient was taught to roll supine to prone and prone to supine, transition from side lying to sitting, and assume quadruped with his head in midline. To entice the infant, the therapist would blow bubbles, place stickers on a mirror, and entertain him with toys to encourage attaining and maintaining different positions such as sitting and reaching activities.

Massage was also used intermittently through the course of treatment. Massage was aimed primarily at the left cervical musculature (SCM, upper trapezius, levator scapulae, and paraspinals) and subcutaneous tissue to aid pain-free range of motion.3

Because of his severe craniofacial asymmetries and misshapened head, the infant was referred for an orthotic device (a helmet) to modify his head shape through a natural remodeling process.12 The main goal of the cranial orthosis is to encourage remodeling of the misshapened head by allowing enough space in the helmet at the flattened areas and to place pressure on other areas to promote symmetry.12 The patient was fitted for a molding helmet during the first month of PT intervention (Fig. 2). The patient’s mother reported that he wore the helmet approximately 23 hours per day.

Fig. 2.:
Molding helmet used by the child early in treatment.

A home exercise program (HEP) was incorporated into the family’s routines and included ways to handle, feed, carry, and position the patient; activities to encourage midline head and trunk posture; and gentle active and passive cervical range of motion exercises.3 The HEP is crucial for infants with torticollis, and parental adherence to the home program for stretching and positioning is vital for successful outcomes. During the course of treatment, updates to the HEP and plan of care were reviewed with the patient’s parents and modified based on gross motor milestones that the child had achieved.


After the first month of PT when the child was 6 months chronological age, the patient had improved passive cervical side bending and rotation (Table 1). He required maximum assistance for rolling supine to prone and prone to supine. Although he tolerated prone propping for several minutes at a time when placed, he could only lift his head slightly off the support surface. Maximum assistance was required for sitting and he tended to lean his trunk to the right with backward rotation of the left trunk/pelvis. This gross motor skill profile characterized developmental delay.

At 7 months of age after 2 months of PT, his cervical side bending and rotation continued to improve. While in the supine or sitting position, he was actively tracking toys through his full cervical rotation to the left. In the prone position, he was able to lift his head 45 degrees off the support surface. He continued to require maximum assistance to roll from the supine to prone position and from the prone to supine position, representing a developmental delay of 1 to 2 months.

By the end of the third month of therapy, his passive cervical side bending to the left side was unchanged but improved to the right. He had no gains in cervical rotation. The patient began to assume a prone on extended arm position and was able to prop sit independently for a few seconds but with unequal weight-bearing through the pelvis.

At 10 months old, he had gained additional left passive cervical rotation and right passive cervical side bending. However, he continued to have difficulty maintaining his head in midline during gross motor activities. In prone, he pushed up onto extended arms for short periods. He did not actively roll from the supine to the prone position or from the prone to supine position independently. He could maintain the quadruped position 30 to 60 seconds with minimum assistance at his hips, although his head was at a 5-degree tilt approximately 50% of time. He could sit independently when placed but could not transition into or out of the sitting position.

As a result of the continued asymmetrical posturing of the head and neck, he was fitted with a tubular orthosis for torticollis (TOT) collar to be worn 1 hour twice daily. The TOT collar is a cervical orthosis that is typically used jointly with exercise to help lateral head tilt that has not resolved with exercise alone.3,21 The TOT collar provides a noxious stimulus to the lateral side of the skull to help activate the impaired side and to achieve and ultimately maintain a neutral head position.3,21 The addition of the TOT collar meant that he wore his collar twice daily and his cranial helmet at night. A radiological examination indicated no increase in head size from the baseline measure.

Description of Outcomes

When assessing the effects of PT intervention on the outcomes of patients with CMT, it is important to consider the initial deficit in cervical rotation, age at presentation, and presence of a palpable mass. The patient was followed until he reached 11 months of age. At that time, he was reassessed using the AIMS. The patient scored between the 5th and 10th percentiles based on his chronological age of 11 months. He was able to transition into sitting and was commando crawling on his stomach 2 to 3 ft, but he primarily scooted on his buttocks for mobility. He was rolling and could maintain a quadruped position but was not creeping on hands and knees. He was not pulling up to stand or to the half-kneel position, and he did not cruise, although he could pull himself up onto his knees at a table.

The patient positioned his head in midline or in a less than 10-degree tilt 75% of the time. He wore the TOT collar 1 to 2 hours per day and his helmet at night. He lacked 5 degrees of passive rotation to left and side bending to the right and had 80 degrees of active right cervical rotation (Table 1). The patient’s head righting reactions were within 10 degrees of neutral to the right and left sides.


Intervention for torticollis should focus on positioning, normalizing range of motion in the cervical region through gentle passive range of motion, treating SCM muscle imbalances, minimizing asymmetry in spontaneous positional and movement preferences, and strengthening through activation of head and trunk muscles. These interventions are designed to foster symmetrical gross motor skills and postural alignment without range of motion or muscle function deficits.2,11,12 Follow-up at the age of 12 months is essential to assess resolution of the torticollis6,12; however, this infant was only available for follow-up until 11 months of age.

At 11 months old, this infant demonstrated significant improvements in passive and active cervical range of motions but lacked consistent midline head control position. He also had gross motor delay. This outcome may be related to his breech presentation at birth with his head turned to the right side. Research indicates that children with a birth history of CMT demonstrate a high incidence of birth trauma and intrauterine malposition,2,4,8 leading to difficulties during labor, with breech delivery being the most common.7,8 The relationship of fetal malposition and birth trauma to CMT is theorized as originating from birth trauma that results in muscle stretching and hematoma formation involving the SCM muscle and leading to fibrosis and muscle contraction.1,2,4,6,8

Another contributing factor to this child’s prolonged CMT and gross motor delay may be his hydrocephalus. There is an absence of research addressing hydrocephalus and CMT. However, research does indicate that hydrocephalus results in synaptic degeneration and negatively affects synaptic plasticity and neurological development.22

Although active and passive cervical range of motion has been shown to be effective for children with CMT, research is needed to determine the effects of hydrocephalus or other comorbidities on outcomes of PT intervention.


CMT is the most common etiology of torticollis. Although the pathophysiology and etiology of CMT are unknown, unilateral shortening and fibrosis of the SCM muscle are apparent during infancy. Plagiocephaly commonly results from CMT.

The initial PT examination should focus on differential diagnosis to assist the physician in ruling out other competing diagnoses such as CPT, ocular abnormalities, osseous abnormalities, and neurological abnormalities. Conservative PT management of infants with CMT should include positioning techniques, gentle range of motion, strengthening activities, and a HEP. One of the primary goals of PT for this population is to prevent facial and skull asymmetry, limitations in cervical range of motion, and long-term postural compensations. The severity of cervical neck rotation restrictions, the presence of a palpable mass, and age at initial treatment are variables that will affect the outcomes of PT intervention.


1.Cheng JCY, Tang SF, Chen TMK, et al. The clinical presentation and outcome of treatment of congenital muscular torticollis in infants—a study of 1,086 cases. J Pediatr Surg. 2000;35:1091–1096.
2.Emery C. The determinants of treatment duration for congenital muscular torticollis. Phys Ther. 1994;74:921–929.
3.Freed SS, Coulter-O’Berry C. Identification and treatment of congenital muscular torticollis in infants. JProsthet Orthot. 2004;16:S18–S23.
4.Golden KA, Beals SP, Littlefield TR, et al. Sternocleiodomastoid imbalance versus congenital muscular torticollis: their relationship to positional plagiocephaly. Cleft Palate Craniofac J. 1999;36:256–261.
5.Kuhns LR, Loder RT, Rogers E, et al. Head-wag automography of the upper cervical spine in infantile torticollis. Pediatr Radiol. 1998;28:464–467.
6.Luther BL. Congenital muscular torticollis. Orthop Nurs. 2002;21:21–28.
7.Ohman A, Beckung E. Functional and cosmetic status in children treated for congenital muscular torticollis as infants. Adv Physiother. 2005;7:135–140.
8.Sonmez K, Turkyilmaz Z, Demirogullari B, et al. Congenital muscular torticollis in children. ORLJ Otorhinolaryngol Relat Spec. 2005;67:344–347.
9.Parikh SN, Crawford AH, Choudhury S. Magnetic resonance imaging in the evaluation of infantile torticollis. Orthopaedics. 2004;27:509–515.
10.Persing J, James H, Swanson J, et al. Prevention and management of positional skull deformities in infants. Pediatrics. 2003;112:199–202.
11.Klackenberg EP, Elfving B, Haglund-Akerlind Y, et al. Inter-rater reliability in measuring range of motion in infants with congenital muscular torticollis. Adv Physiother. 2005;7:84–91.
12.Van Vlimmeren LA, Hekders PJM, Van Adichem LN, et al. Torticollis and plagiocephaly in infancy: therapeutic strategies. Pediatr Rehabil. 2006;9:40–46.
13.Williams CRP, O’Flynn E, Clarke NMP, et al. Torticollis secondary to ocular pathology. J Bone Joint SurgBr. 1996;78B:620–624.
14.Berry DS, Moriarty RA. Atlantoaxial subluxation related to pharyngitis: Grisel’s syndrome. Clin Pediatr (Phila). 1999;38:673–676.
15.Mezue WC, Taha ZM, Bashir EM. Fever and acquired torticollis in hospitalized children. J Laryngol Otol. 2002;116:280–284.
16.D’Angelo LK, Rose RAU. The special care nursery. In: Campbell SK, Vander Linden DW, Palisano RJ, eds. Physical Therapy for Children. Philadelphia, PA: W.B. Saunders Company; 2006:1053–1097.
17.Jeng S, Yau KT, Chen L, et al. Alberta Infant Motor Scale: reliability and validity when used on preterm infants in Taiwan. Phys Ther. 2000;80:168–178.
18.Leach J. Orthopedic conditions. In: Campbell SK, Vander Linden DW, Palisano RJ, eds. Physical Therapy for Children. Philadelphia, PA: W.B. Saunders Company; 2006:481–515.
19.Baronciani D, Atti G, Andiloro F, et al. Screening for developmental dysplasia of the hip: from theory to practice. Pediatrics. 1997;99:E5.
20.American Physical Therapy Association. Guide to Physical Therpist Practice. 2nd ed. Alexandria, VA: American Physical Therapy Association; 2003;145–160.
21.Symmetric Designs. TOT collar web page. Available at: http://www.symmetric-designs.com/TOT_collar.html. Accessed June 2009.
22.Castejon OJ. Synaptic plasticity and synaptic degeneration in human congenital hydrocephalus. J Pediatr Neurol. 2008;6:99–107.
23.Ohman AM, Beckung ERE. Reference values for range of motion and muscle function of the neck in infants. Pediatr Phys Ther. 2008;20:53–57.

differential diagnosis; human movement system; infant; physical therapy; torticollis

© 2009 Lippincott Williams & Wilkins, Inc.