Congenital muscular torticollis (CMT) is a musculoskeletal deformity, observed in infancy, characterized by unilateral contracture of the sternocleidomastoid (SCM) muscle.1–4 Clinical presentation consists of persistent head tilt toward the involved side with the chin rotated toward the contralateral shoulder.5–7 CMT is further subdivided into 3 groups on the basis of clinical presentation: infants with sternomastoid tumor (SMT), muscular torticollis (MT), and postural torticollis (POST).5–7 Infants in the SMT group present with a palpable fibrotic mass in the substance of the affected SCM and cervical range of motion (ROM) limitations. Muscular torticollis (MT) is defined as the presence of limitations in active and passive cervical ROM because of tightness in the SCM without a mass. Infants with POST have an appearance of CMT without the presence of a mass or passive ROM limitation.2,5,7 The majority of infants and children with CMT achieve good to excellent outcomes with conservative physical therapy.7–9 Prognosis for full resolution of MT and length of intervention varies depending on the age at onset of intervention, severity of ROM restrictions, and presence of a mass in the SCM muscle. Surgical intervention is necessary in 1% to 9.1% cases of infants with CMT.2,3,10–12
The Academy of Pediatric Physical Therapy of the American Physical Therapy Association published an evidence-based clinical practice guideline (CPG) on Physical Therapy Management of Congenital Muscular Torticollis.5 The guideline provides instructions for screening, monitoring, optimal treatment approach, and discharge criteria. Surgery is identified as a traditional approach for treatment of children with CMT who have failed conservative management, but is otherwise not described in the guidelines.
Surgical management of CMT typically involves children with severely involved SCM.2,6,7,10–14 Ultrasonography is the preferred type of diagnostic imaging for CMT.13 CMT is classified according to the severity of fibrosis within the SCM, which has correlated with clinical presentation, duration of treatment, and clinical outcomes.14,15 Infants with severe fibrosis in the entire SCM muscle typically require longer treatment duration and are more likely to need surgical intervention than infants with mild fibrosis. Ultrasound findings of SCM fibrosis in CMT have been classified into 4 types. Type 4 is the most severe and defined as a fibrotic tight cord in the entire SCM.11,16 Children with type 4 fibrosis are 13.4 times more likely to require surgery than those with type 1 fibrosis.14 Understanding CMT classification on the basis of ultrasonographic images clarifies why some infants, despite consistent therapeutic intervention, have slow improvement in passive and active ROM.
Although accounts of surgical techniques and outcomes are reported, description of postoperative physical therapy guidelines and the potential challenges encountered during rehabilitation are limited.14–23 Children who require surgery have prolonged experience in atypical postures, resulting in potential asymmetrical development of the visual, vestibular, and proprioceptive systems.24,25 This presentation of 2 postsurgical cases includes examination before surgery, surgical methods, physical therapy intervention with specific treatment techniques, and discharge criteria. In addition to first-choice interventions for CMT as outlined in the CPG,5 this article describes physical therapy-specific treatment techniques aimed at reestablishing perception of midline by integration of visual, vestibular, and proprioceptive stimuli. The resulting criterion-based guidelines may be used as a reference for physicians and clinicians working with this population.
This 2-year-old boy with right CMT diagnosed at 4 weeks of age had an unremarkable birth history except for suction-assisted delivery. Parents noted a head tilt soon after delivery and at the 4-week checkup the pediatrician prescribed “stretches.” By 2 months of age, the child was receiving physical therapy several times per week as an outpatient and then transitioned to early intervention 3 times per week at home and continued therapy up to the time of surgery. A cranial molding helmet was worn from age 6 to 9 months. His parents noted an increased head tilt when wearing the helmet and chose to discontinue use. All developmental milestones were achieved within the lower limits of normal range as reported by the parents. The child presented to the authors' institution for a presurgical evaluation at 29 months of age. Examination demonstrated resting head tilt varying between 10° and 20° in sitting and 15° in supine positions. Cervical passive and active rotations were within normal limits and symmetrical. Limited passive cervical lateral flexion to the left was present: 40° versus 65° to the right, as measured by goniometry with a 2-person measuring technique.26 He presented with a 3-grade discrepancy in the lateral cervical flexion muscle strength, measured on the Muscle Function Scale (MFS)27 and presented as CMT severity classification grade 7.5 Pain was recorded as 0/10 on the Face, Legs, Activity, Cry, Consolability (FLACC) scale. At 29 months of age, this child underwent a bipolar release of the right SCM muscle.
This 2-year-old girl, triplet A, was diagnosed with severe left CMT; her SCM was severely fibrotic and clinically presented as type 4 fibrosis. She was born at 27 weeks' gestation, sustained a grade III intraventricular hemorrhage (IVH), and stayed for 3 months in the neonatal intensive care unit. The child was followed for medical visits in the clinic at the hospital where she was born. She was seen by a neurologist because of her history of prematurity and IVH. However, her neurological examination was noted to be normal within the limits of her torticollis. Her infant visual screen was normal. She received outpatient physical therapy (at our facility) 2 to 3 times per week from 5 months of age until surgical release was performed. Preoperative therapy consisted of cervical passive ROM, active ROM of the cervical spine, trunk, and upper extremities, development of symmetrical movement strategies, environmental adaptations, caregiver education, and daily home program. The child wore 2 cranial remodeling helmets to address severe plagiocephaly between ages of 7 and 12 months.
At the presurgical physical therapy examination, the child presented with a 35° head tilt to the left, 15° of passive cervical lateral flexion to the right versus 70° to the left; 60° of passive cervical rotation to the left versus 90° to the right as measured by goniometry with a 2-person measuring technique (Table 1).26 A 3-grade discrepancy was found in muscle strength between right and left cervical lateral flexors on the MFS.27 Pain was recorded as 0/10 on the FLACC scale.
The child presented with a marked resting head tilt to the left with rotation to the right, compensatory trunk rotation to the left, severely limited active cervical lateral flexion and rotation, end-range left shoulder tightness, decreased left hand use, and left upper and lower extremity weakness. Other impairments were left upper extremity visual neglect, movement asymmetry, asymmetrical transitions, vestibular deficits, and impaired body awareness. It is possible that because of this child's history of prematurity and IVH, her visual and sensory impairments may have had a neurological component that was amplified by the physical restriction of a severely fibrotic SCM. At 25 months of age, this child underwent a bipolar release of her left SCM.
There is no established agreement among surgeons on the optimal timing and technique of SCM muscle releases.12,17,18,20–23,28–31 Although results in children younger than 3 years are excellent, children treated surgically in the first year of life often require a second surgery because of recurrence related to hematoma or failure to comply with postsurgical therapy and difficulty with effective bracing for children younger than 2 years.12 Postponement of surgery is often recommended until the patient and parents can successfully comply with a postoperative bracing and exercise program.12,17 Although the authors of these articles stated that success of surgery depends on appropriate surgical technique, intensive postoperative physical therapy, and use of a cervical brace, none of the articles described physical therapy treatment and bracing protocols in detail.
At our facility, families are encouraged to wait for surgery until the child is at least 2 years of age for several reasons; by 2 years, patients have had the opportunity to exhaust all conservative measures, the postoperative brace has better congruence when the child is older, and the families have an opportunity to reconcile themselves to the fact that the child requires surgical intervention and commit to the postoperative rehabilitation program (Table 2). The most common surgical approaches for muscular torticollis are unipolar and bipolar releases.12,17,22
TABLE 2 -
Rehabilitation Guidelines for Postoperative Management of SCM Release
|Timeframe Main Goal
Phase I POD 1-2
Pain Management and Functional Mobility
||Phase II POD 3 to wk 8 ROM, Strength, and Midline
||Phase III wk 8-24 Functional Maintenance of Midline
||Patient and caregiver education
Control postoperative pain
Restore independence with functional mobility
Patient and caregiver independent with don/doff soft collar
|Patient and caregiver education
Maximize functional strength of cervical muscles
Develop midline awareness/control
Develop active head righting reactions
Develop proprioceptive awareness
Patient and caregiver independent with don/doff pinless halo
|Independent home exercise as instructed
Equal active and passive range of motion
Symmetrical head righting in all positions
Maintain head in midline in all developmental positions ≥95% of time
Symmetrical gross motor skills
||Monitor pain level
Maintain spinal precaution
Observe skin for signs of breakdown from orthosis
|Perform gentle stretching
Monitor signs of discomfort during therapeutic exercise, ADLs, and functional mobility
Avoid irritating incision
Avoid compensatory movement patterns, and postures
|Recurrence of tilt upon discharge of pinless halo
Compensatory movement patterns
||Functional mobility: bed mobility, log rolling, transfers, gait, stair training
Education about skin management
Donning/doffing the orthosis
Home exercise program
Home exercise program instructions
A/AA/PROM of cervical spine and UE
Facilitate midline head orientation
Cervical and core strengthening
Head righting reactions
Therapeutic ball activities
Use tactile, visual, and vestibular feedback
Increase awareness and use of ipsilateral upper extremity:
Restricted use of contralateral UE
Weight bearing through ipsilateral UE
Reaching with ipsilateral UE
Fine motor with ipsilateral UE
Abbreviations: AAROM, active assistive range of motion; ADL, activity of daily life; AROM, active range of motion; MFR, myofascial release; POD, postoperative day; PROM, passive range of motion; ROM, range of motion; SCM, sternocleidomastoid; STM, soft tissue massage; TOT, Tubular Orthosis for Torticollis; UE, upper extremity.
Phase I: Inpatient Acute Care
Postoperative Days 1 to 2. Physical therapy begins in the hospital with emphasis on basic postoperative spinal care. The therapist provides the patient and caregiver education about body mechanics and bed mobility with log rolling to protect the operative site and minimize pain. The patient may initially experience unsteadiness because of altered center of mass. The therapist therefore reviews safe transfers, gait, and stair climbing. The patient is usually discharged from the hospital on postoperative day 1 when the patient and caregivers are independent with all mobility and orthotic management, and pain is well controlled. Before discharge, the therapist reviews the outpatient plan of care, emphasizing the importance of compliance with therapy, and daily home exercise program (HEP).
Upon discharge from the hospital or at the first postoperative visit with the surgeon, the child is transitioned from a soft cervical collar to a pinless halo (Figures 1B and 1C). The child's head and neck are immobilized in an overcorrected position, slightly laterally flexed (∼5°) toward the unaffected side, and slightly rotated toward the involved side to elongate the soft tissues as they heal. The halo is always removed during physical therapy and HEP.
Phase II: Outpatient Rehabilitation: ROM, Strength, and Midline
Postoperative Day 3 to Week 8. The subacute phase of rehabilitation begins on postoperative day 3 or 4 at follow-up with the physician. Initially physical therapy is recommended 3 times per week with a daily HEP. The goals of this phase are to optimize cervical passive and active ROM, maximize functional strength of the cervical musculature, and develop midline awareness and control. The therapist works to advance active head righting reactions and improve the patient's proprioceptive awareness. It is important that all stretching is performed gently and the child is monitored for signs of discomfort during therapeutic exercise and functional mobility. In addition, the therapist needs to be aware of compensatory movement patterns and postures.
Education should be incorporated into each treatment session. It is important that the caregivers carry over the cervical exercises at home. The therapist should demonstrate appropriate gentle stretching and have the caregivers perform the exercises in the therapy session to ensure appropriate technique. The family should be instructed to monitor the incision site for signs of irritation or infection. The child's HEP consists of active and passive cervical rotation and lateral flexion, active strengthening of the uninvolved cervical lateral flexors, and scar massage (once incision is healed). It should be performed 4 to 6 times per day.
Therapeutic treatment recommendations include the same 5 first-choice interventions recommended by the CPG: neck passive range of motion (PROM), neck and trunk active range of motion, development of symmetrical movement, environmental adaptations, and caregiver education.5 In addition, active assistive ROM and cervical and core-strengthening therapeutic exercises are important (Figure 2A). Development of symmetrical movement in older children with well-established compensations may be challenging. Visual-motor activities, therapeutic ball activities, scapula stabilization, upper extremity weight bearing, and bimanual activities are used with a focus on the child incorporating tactile, visual, and vestibular feedback. Additional intervention strategies focus on facilitation of midline head orientation, affected upper extremity strength and fine motor skills, bimanual activities, and visual-motor exercises combined with vestibular activity (Figures 2B-2E).
Criteria for Advancement
At 6 to 8 weeks postsurgery, the child is reexamined by the physician. If progress is satisfactory, the wearing schedule of the brace is decreased to night use. The child is ready to progress to phase 3 of rehabilitation when his or her active and passive ROM measures are within 5° bilaterally and cervical lateral flexion strength is within 1 grade bilaterally on the MFS.
Phase III: Outpatient Rehabilitation: Functional Maintenance of Midline Weeks 8 to 24
The goals for phase III are to achieve equal active and passive ROM bilaterally, establish symmetrical head righting in all positions, maintain head in midline in all developmental positions at least 95% of time, demonstrate symmetrical gross motor skills, and have the child and caregivers independent with an updated HEP. Therapists must monitor for recurrence of the head tilt upon discharge of the pinless halo (typically around 10-12 weeks post-surgery) and habitual compensatory movement patterns.
Treatment recommendations include continuation of activities from phase II with the addition of kinesiotaping and a Tubular Orthosis for Torticollis (TOT) collar as needed to promote sustained midline head orientation (Figure 2F). To address persistent motor asymmetries, activities from phase II are progressed to be more challenging and complex to meet specific needs of the child.
Criteria for Discharge
The child is ready for discharge from physical therapy when he or she has achieved symmetrical active and passive cervical ROM, symmetrical head righting, and symmetrical cervical lateral flexion muscle strength. The child must demonstrate the ability to maintain head in midline in all developmental positions at least 95% of time and perform age-appropriate, symmetrical gross motor skills. Finally, the family must understand how to monitor for signs of regression and be independent with HEP.
Children with torticollis present with a variation in presentation and course that must be managed on an individual basis. That is why we propose the above physical therapy management as guidelines rather than a strict protocol. According to the CPG, a child should be referred to the primary pediatrician and a specialist when torticollis is not resolving with conservative management.5 Both children in this case study were regularly followed up by a pediatrician and pediatric orthopedist before surgery. Because of the severity of their clinical presentations, the children received physical therapy to optimize midline posture, maximize cervical ROM, and foster symmetrical developmental skills up to the time of surgery. Postoperatively, they received intensive therapy as described later to allow each child to achieve full active cervical ROM, symmetrical movement patterns, and midline posture with the newly gained cervical passive ROM.
Postsurgical, outpatient physical therapy evaluation took place 4 days after discharge. The patient had 1 to 2/10 pain scores on the FLACC scale and decreased cervical active and passive ROM in all directions because of postoperative discomfort. Without the brace, he maintained his head in midline in supine positions but demonstrated a 10° right tilt in sitting and standing positions. He demonstrated asymmetrical posturing and transitions. When standing and ambulating, the patient's weight was shifted slightly over the right side and his equilibrium and balance were challenged by the new posture.
Initial outpatient treatment frequency was 3 times per week, and decreased to 2 times per week in phase III. After 3 months of therapy, the child demonstrated full active and passive ROM and was able to achieve midline head orientation and maintain his head in less than 5° of tilt 90% of the time during therapy sessions. He continued with an increased right head tilt only when concentrating on difficult tasks. The child was discharged from outpatient PT but continued with an HEP and early intervention services at home. During follow-up visits to the surgeon, the child's father reported that the right head tilt returns when the child has a growth spurt, and the family manages it independently with cervical stretches and strengthening exercises. Four years after discharge from therapy, the child returned to therapy for 4 additional sessions to strengthen his cervical muscles, to regain midline head orientation, and establish an updated HEP. The patient was discharged maintaining midline greater than or equal to 95% of the time in all developmental positions. Parents were instructed to continue a maintenance exercise program at home.
Postsurgical, outpatient physical therapy evaluation took place 4 days after discharge. Initial outpatient physical therapy frequency was 3 times per week, with a daily HEP of gentle cervical stretches. The therapist suggested that parents use a log to track the stretches performed. The child received physical therapy at home through early intervention.
Within a few sessions, the therapist noted improvements in midline head position, with ambulation and increased attention to the right side of her visual field. Pain was 0/10 on the FLACC scale. The child was making gains with therapy, demonstrating increased cervical passive and active ROM, improved head alignment with sitting, standing, and ambulation, and increased independent use of her left hand. Despite increased cervical ROM, she had difficulty dissociating her head and neck from her trunk and continued to rotate her body when looking to the left. She presented with apparent gravitational insecurity and was hesitant to participate in vestibular activities. About 1 month after surgery, the therapist noted decreased midline orientation, decreased active rotation to the left side, and slight cervical rotation to the right without tilt with all activities. At approximately 3 months postsurgery, the child transitioned to wearing the pinless halo at night only. At about this time, the child began to demonstrate a slight tilt to the left and rotation drift to the right. The therapist applied kinesiotape in an effort to facilitate the contralateral SCM. The TOT collar was initiated at approximately 3.5 months postsurgery and used at home daily for 2 to 3 hours. The therapist modified the collar by adding an extra strut on the right side to prevent rotation drift (Figure 1D). To address decreased rotation to the left and decreased use of the left hand, the therapist constrained the right arm during therapy, with a soft strap attached to the child's waist while engaging her in activities, incorporating fine and gross motor skills (Figure 2D). Her parents were instructed to continue this at home daily. By 4 months postsurgery and 3 weeks after the TOT collar was initiated, the child began to demonstrate active midline head orientation. At 5 months, she had full cervical PROM and the frequency of outpatient physical therapy was decreased to twice per week. The child's alignment was symmetrical during all activities at 6 months postsurgery. Outpatient therapy was decreased to 1 time per week. At 9 months postsurgery, a 5° to 10° left head tilt reemerged; however, PROM was symmetrical and full. The therapist continued to focus on cervical strengthening of the right side and midline activities to address return of mild head tilt.
After 11 months of an intense rehabilitation program, the child achieved full active and passive cervical ROM, and symmetrical cervical muscle strength on MFS (5/5). She maintained her head in midline in all postures, transitioned with symmetrical head righting, and performed age-appropriate gross and fine motor skills without side preference. The therapist recommended monthly follow-up for 3 months. The child continued with early intervention at home, but the family did not attend scheduled outpatient appointments.
CMT poses a biomechanical problem for the developing infant. Infants with severe CMT learn to move their bodies by compensating for their shortened SCM. Children learn skilled movement through intense practice each day.32 Therefore, children with severe presentation of CMT practice for hours a day for many months in the tilted and rotated position of the head, learning to compensate for the mechanical limitation in their necks. Typically, cases that result in surgical management of CMT tend to be children who have prolonged experience in atypical postures, resulting in asymmetrical development of motor and sensory systems.
As an infant with CMT develops motor skills, each particular movement pattern is the result of the dynamic interaction of the participating subsystems that organize with respect to the demands of the task and environmental context. Subsystems that may be involved are postural control (delayed balance and equilibrium reactions), body constraints (tight SCM, limited cervical ROM, limited shoulder flexion and abduction, etc), muscle strength (weak contralateral SCM, weak shoulder girdle muscles on the involved side, weak abdominals, etc), perceptual processes (visual, vestibular, and proprioceptive), cognition, and motivation. At every stage of development, movement emerges from maturing subsystems.33,34 As described earlier, in an infant with CMT some of the systems are limited or delayed because of the biomechanical restrictions created by this condition.35 In the case of a child with CMT, the pattern of movement arises as dynamic interplay of biomechanical body constraints, and asymmetrical, uneven forces generated by asymmetrical movement. A child with CMT will reinforce the atypical pattern learned because of an asymmetrical head position. With every asymmetrical movement and transition, the child strengthens the motor and visual pathways in his cortex, reinforcing the asymmetry.
The CMT CPG recommends similar treatment to nonoperative management of CMT.5 However, the postoperative management of a child includes a broad repertoire of treatment techniques. This repertoire is needed because of the child's developmental level, well-established compensatory postures, and skewed perception of midline. In addition to establishing full active and passive ROM, the intervention for children with severe CMT who undergo surgical release should be directed at reestablishing perception of midline using visual, vestibular, and proprioceptive inputs and development of symmetrical muscle strength throughout the body, symmetrical transitions, improved postural control, and quality of movement. Although the CPG recommends postoperative treatment duration of 4 weeks to 4 months, we believe that a longer follow-up and extended monitoring may be indicated for some of the children for a lasting change in a child's midline posture and visual perceptual, proprioceptive, and vestibular systems. Postoperative recovery is not a linear path, but rather may be sinusoidal in nature with a series of ebbs and flows in the child's progress to maintenance of midline.
In conclusion, CMT affects young children, presenting them with biomechanical challenges that they must solve as they master motor skills. The constant head tilt and asymmetries of movement may influence development of visual, vestibular, and proprioceptive systems, resulting in challenges with postural control. When a child undergoes surgical release of the tight SCM, an intensive and extensive postsurgical physical therapy program is recommended.
1. Salter RB. Congenital abnormalities. Textbook of Disorders and Injuries of Musculoskeletal System. 3rd ed. Philadelphia, PA: Williams & Wilkins Company; 1998:171.
2. Cheng JCY, Tang SP, Chen TMK, Wong MWN, Wong EMC. The clinical presentation and outcome of treatment of congenital muscular torticollis in infants—a study of 1,086 cases. J Pediatr Surg. 2000;35(7):1091–1096.
3. Emery C. The determinants of treatment duration for congenital muscular torticollis. Phys Ther. 1994;74(10):921–929.
4. Karmel-Ross K. Congenital muscular torticollis. In: Campbell SK, ed. Physical Therapy
for Children. 4th ed. St Louis, MO: Saunders Elsevier; 2012:359–380.
5. Kaplan SL, Coulter C, Fetters L. Physical therapy
management of congenital muscular torticollis: An evidence-based clinical practice guideline: from the Section on Pediatrics of the American Physical Therapy
Association. Pediatr Phys Ther. 2013;25(4):348–394.
6. Kwon DR, Park GY. Diagnostic value of real-time sonoelastography in congenital muscular torticollis. J Ultrasound Med. 2012;31(5):721–727.
7. Cheng JCY, Wong MWN, Tang SP, Chen TMK, Shum SLF, Wong EMC. Clinical determinants of the outcome of manual stretching in the treatment of congenital muscular torticollis in infants. J Bone Joint Surg Am. 2001;83-A(5):679–687.
8. Cheng JCY, Chen TMK, Tang SP, Shum SLF, Wong MWN, Metreweli C. Snapping during manual stretching in congenital muscular torticollis. Clin Orthop Relat Res. 2001;(384):237–244.
9. Chen MM, Chang HC, Hsieh CF, Yen MF, Chen TH. Predictive model for congenital muscular torticollis: analysis of 1021 infants with sonography. Arch Phys Med Rehabil. 2005;86(11):2199–2203.
10. Petronic I, Brdar R, Cirovic D, et al. Congenital muscular torticollis in children: distribution, treatment duration and outcome. Eur J Phys Rehabil Med. 2009;45(1):6.
11. Lee YT, Yoon K, Kim YB, et al. Clinical features and outcome of physiotherapy in early presenting congenital muscular torticollis with severe fibrosis on ultrasonography: a prospective study. J Pediatr Surg. 2011;46(8):1526–1531.
12. Cheng JC, Tang SP. Outcome of surgical treatment of congenital muscular torticollis. Clin Orthop Relat Res. 1999;(362):190–200.
13. Suhr MC, Oledzka M. Considerations and intervention in congenital muscular torticollis. Curr Opin Pediatr. 2015;27(1):75–81.
14. Tang FT, Hsu KH, Hsu CC, Wong AMK, Chang CH. Longitudional follow-up study of ultrasonography in congenital muscular torticollis. Clin Orthop Relat Res. 2002;403(10):179–188.
15. Tang S, Liu Z, Quan X, Qin J, Zhang D. Sternocleidomastoid pseudotumor of infants and congenital muscular torticollis: fine-structure research. J Pediatr Orthop. 1998;18(2):214–218.
16. Lee YT, Cho SK, Yoon K, et al. Risk factors for intrauterine constraint are associated with ultrasonographically detected severe fibrosis in early congenital muscular torticollis. J Pediatr Surg. 2011;46(3):514–519.
17. Shim JS, Jang HP. Operative treatment of congenital torticollis. J Bone Joint Surg Br. 2008;90(7):934–939.
18. Kozlov Y, Yakovlev A, Novogilov V, et al. SETT—subcutaneous endoscopic transaxillary tenotomy for congenital muscular torticollis. J Laparoendosc Adv Surg Tech A. 2009;19(suppl 1):S179–S181.
19. Burstein FD, Cohen SR. Endoscopic surgical treatment for congenital muscular torticollis. Plast Reconstr Surg. 1998;101(1):20–24; discussion 25-26.
20. Burstein FD. Long-term experience with endoscopic surgical treatment for congenital muscular torticollis in infants and children: a review of 85 cases. Plast Reconstr Surg. 2004;114(2):491–493.
21. Lee IJ, Lim SY, Song HS, Park MC. Complete tight fibrous band release and resection in congenital muscular torticollis. J Plast Reconstr Aesthet Surg. 2010;63(6):947–953.
22. Jones CD, Nakhdjevani A, Lidder S. Surgical management of idiopathic torticollis secondary to a fibrotic band. Orthop Rev (Pavia). 2012;4(3):e27.
23. Shim JS, Noh KC, Park SJ. Treatment of congenital muscular torticollis in patients older than 8 years. J Pediatr Orthop. 2004;24(6):683–688.
24. Hylton N. Infants with torticollis: The relationship between asymmetric head and neck positioning and postural development. Phys Occup Ther Pediatr. 1997;17(2):91–117.
25. Schertz M, Zuk L, Zin S, Nadam L, Schwartz D, Bienkowski RS. Motor and cognitive development at one-year follow-up in infants with torticollis. Early Hum Dev. 2008;84(1):9–14.
26. Klackenberg EP, Elfving B, Haglund-Akerlind Y, Carlberg EB. Intrarater reliability in measuring range of motion in infants with congenital muscular torticollis. Adv Physiother. 2005;7(2):84–91.
27. Ohman AM, Beckung ER. Reference values for range of motion and muscle function of the neck in infants. Pediatr Phys Ther. 2008;20(1):53–58.
28. Rajput AGM. The surgical management of congenital muscular torticollis. Phys Occup Ther Pediatr. 1997;17(2):69–80.
29. Lee TG, Rah DK, Kim YO. Endoscopic-assisted surgical correction for congenital muscular torticollis. J Craniofac Surg. 2012;23(6):1832–1834.
30. Seyhan N, Jasharllari L, Keskin M, Savaci N. Efficacy of bipolar release in neglected congenital muscular torticollis patients. Musculoskelet Surg. 2012;96(1):55–57.
31. Ta JH, Krishnan M. Management of congenital muscular torticollis in a child: a case report and review. Int J Pediatr Otorhinolaryngol. 2012;76(11):1543–1546.
32. Adolph KERS. Motor development. In: Liben LS, Mueller U, eds. Handbook of Child Psychology and Developmental Science. 7th ed. New York, NY: Wiley; 2015:113–157.
33. Perry SB. Clinical implications of a dynamic systems theory. J Neurol Phys Ther. 1998;22(1):4–10.
34. Sporns O, Tononi G, Edelman GM. Connectivity and complexity: the relationship between neuroanatomy and brain dynamics. Neural Netw. 2000;13(8–9):909–922.
35. Heriza CB. Implications of a dynamical systems approach to understanding infant kicking behavior. Phys Ther. 1991;71(3):222–235.