Brachial Plexus Birth Injury and Gross Motor Function: A Scoping Review

Abstract

Purpose: Brachial plexus birth injury (BPBI) is a neonatal injury occurring in 1.24 in 1,000 live births. The result of this injury on arm function is highly variable and has been the subject of many studies. However, the effect of BPBI on the development of overall gross motor function is less well studied. We aimed to synthesize the available literature on posture, balance and coordination, and gait in children with BPBI. Method: A scoping review was conducted by searching five databases (MEDLINE, EMBASE, CINAHL, PEDro, and Web of Science) and the grey literature for all study types related to our question. Studies unrelated to birth injuries, animal studies, and literature reviews were excluded. Three researchers independently screened the studies during two rounds of review (title/abstract and full-text). Results: Of the 2,728 articles found, 16 articles were included. Overall, the average study quality was 0.90 out of 1.00. These studies suggest that observed postural deficits in BPBI are secondary to asymmetry rather than true scoliosis. Further, the asymmetrical nature of the injury results in both balance deficits and gait abnormalities when compared to healthy age-matched populations. Conclusions: The scoping review demonstrates that while there are obvious consequences to overall motor function and development in BPBI, these effects are likely under-studied. Further research should focus on understanding overall developmental differences in children with BPBI. Expanding on this information could possibly allow for earlier intervention, extended scope of physiotherapy, and better functional outcomes.

Brachial plexus birth injury (BPBI) is a condition caused by a traction injury to the brachial plexus during delivery. The reported global incidence of injury is between 0.4 and 4 out of 1,000 live births.¹ In Canada, this incidence is approximately 1.24 in 1,000 live births.² Some of these injuries will self-resolve, and as such the rate of persistent OBPP is approximately 1–2 per 10,000 live births.³ BPBI severity can range from neurapraxia to complete root avulsions with the presentation depending on whether a total or upper injury has occurred. As such, the function of sensory, motor, and autonomic nerve fibers in the affected limb varies between individuals. Upper lesions are the most common type and present with an internally rotated shoulder, pronated arm, and extended elbow. Whereas total plexus involvement results in a flaccid arm with both sensory and motor deficits to the fingers. If these injuries persist, structural changes to the shoulder, elbow, forearm, and wrist often occur during development. Patients can present with varying degrees of arm weakness and asymmetrical movements.⁴ The sequelae of the injury depend on the extent and location of the injury, but most commonly, there is some degree of functional impairment.

Most studies have narrowed their investigations to the effect of BPBI on the function of the affected arm, and few report on the global impact on development through measures such as activities of daily living (ADL) and participation in sports. For example, Butler and colleagues⁵ and van der Holst and colleagues⁶ found that adolescents and adults with BPBI report functional deficits and participation restrictions. In contrast, no participation restrictions were described by Bae and colleagues, who reported that 88% of children with BPBI between the ages of 6 and 18 participated in team and individual sports at a recreational to an elite-level, including sports requiring an upper extremity skill.⁷ Strömbeck and colleagues⁸ and Kirjavainen⁹ have also found, in their long-term follow-up studies of 70 and 112 children respectively, that by modifying some activities, most children living with BPBI can complete their ADL independently. However, it should be noted that the causal direction between better motor function and participation in sports and ADL remains unclear, and multiple factors including severity of BPBI,⁹ surgical treatment,⁷ and self-confidence¹⁰ may contribute in the long term.

Nonetheless, most adults with BPBI report pain, postural deficits, and disability with increasing age, suggesting a potential gap in the management and rehabilitation of these injuries.¹¹ Persistent limitation in overall motor function may be due to associations between BPBI and injury-related pain¹² and neurological deficits.¹³ From an early age, many children with BPBI do not bear weight or perform tasks symmetrically which can alter their postural control and result in compensatory movements. While this area is not well studied, some work has suggested that altered muscle growth and imbalance may be linked to postural and bone deformity.¹⁴ Thus, the long-term effects of these compensatory movements does remain a theory for the continued functional deficits and chronic pain in adulthood.¹¹

Overall, the long-term outcomes of overall gross motor function in people with BPBI appear to be an under-researched topic in the literature. To date, no review has been published summarizing the research in this area. This study aims to synthesize the current literature of BPBI on three domains of gross motor function: (1) posture, (2) balance and coordination, and (3) gait. We elected to pursue a scoping review, given the breadth of this topic. The results of this study will aid in identifying the spectrum of future rehabilitation needs for children with BPBI and determining areas where further investigation is required.

Methods

A population, intervention, comparison, and outcome (PICO) format was used to develop our clinical question. Scoping review methodology was informed by Arksey and O’Malley,¹⁵ with updates from Levac and colleagues.¹⁶ Eligibility criteria were decided on prior to consulting with a medical librarian to create a search strategy. Databases searched included MEDLINE, EMBASE, CINAHL, PEDro, and Web of Science. A search for ongoing studies was also conducted on ClinicalTrials.gov. Finally, the grey literature was searched using Global ETD and WorldCat resources: papersfirst, proceedingsfirst, and dissertations. The final search was completed on April 27, 2021. Appendix 1 shows the search key words in detail. The findings of this study were reported in accordance to the PRISMA Extension for Scoping Reviews (PRISMA-ScR) checklist by Tricco and colleagues.¹⁷

Eligibility

For this scoping review, inclusion criteria for article screening included: (1) discussion of BPBI at any age, and (2) results on at least one of the gross motor domains (gait, balance and coordination, and/or posture). Exclusion criteria were: (1) studies unrelated to BPBI, such as traumatic brachial plexus injuries, cerebral palsy, animal studies, or studies with unclear terminology. Of note, no studies were excluded based on comorbidities. All study types were included except for literature reviews. Thus, the studies reviewed included cohort, case-control, randomized controlled trials, case reports, dissertations, poster or oral presentations, and commentaries. Studies of any year or language were considered.

All articles were initially uploaded to CADIMA.¹⁸ After removing duplicates, three researchers screened the articles by title and abstract based on the inclusion criteria listed above. The full text of articles that passed title and abstract screening were then divided evenly and independently reviewed by two of the three authors for a second round of screening. Articles for which the full text was not readily available were obtained via an inter-library loan programme or by direct emails to the authors. Where full texts were not available, data were extracted from the available abstracts. Consensus was completed via discussion by the authors after each full text screen to resolve any conflicts.

Data extraction

Two investigators independently completed data extraction from each of the final 16 studies using COVIDENCE.¹⁹ Data were recorded on a pre-prepared template and consensus was achieved again at the end of the data extraction.

Data were collected for various categories including general information, participant characteristics, the domain(s) of gross motor function studied, functional assessment tools, and significant study findings. Study quality summary scores were calculated with the QualSyst tool (total score divided by total possible score to give a summary score ranging from 0, lowest quality, to 1, highest quality).²⁰ The data were then separated into our four domains of interest, analyzed by the reviewers, and summarized.

Results

Study characteristics

There were 16 total articles included after the screening process described in Figure 1. The included studies were published between 1984 and 2021, and were all in the English language. Eight studies were cross-sectional studies, one of which was a dissertation, and five studies were cohort studies, two of which were retrospective. There were two text and opinion pieces and one abstract included. Five of the studies were conducted in Turkey, five from other parts of Europe, and four in North America. Some studies included more than one domain of function. As such, eight studies discussed posture, six discussed balance, six discussed coordination, and four discussed gait. Sample sizes varied between 5 and 112 participants. The age range across all included studies ranged between 1 week and 32 years of age. The average study quality was 0.90 out of 1.00, and scores ranged from 0.80 to 0.95. There was almost perfect agreement between the study quality assessments of the two independent reviewers, κ = 0.834 (95% CI: 0.755, 0.913). Table 1 summarizes the characteristics and results of the 16 articles.

Figure 1. Study identification and selection process.

Table 1.

Study Characteristics and Key Findings (Organized by Publication Date)

Author	Year	Country	Study type	Sample size, n	Age range	Domains of interest	Key measurement tool(s)	Key findings	QualSyst summary score19
Strombeck et al.8	2007	Sweden	Retrospective cohort	70	7–20 y	Posture	Clinical assessment for signs of scoliosis	No study participants displayed signs of scoliosis	0.91
Grodner et al.29	2007	Poland	Text and opinion	ns	1 w–16 y	Posture	N/A	Muscle imbalance and asymmetry caused abnormal thoracic curvature and exaggerated lumbar lordosis	N/A
Kirjavainen et al.23	2009	Finland	Cross sectional	111	5–32 y	Posture, Gait, balance	Clinical measurement of coronal posture, Mallet System, Gilbert score, Raimondi score	1. Diminished or asymmetrical motion during gait was associated with Mallet System score < 3 (35% vs. 14%, p = 0.0092), Gilbert score < 3 (31% vs. 10%, p = 0.0038), and Raimondi score < 4 (38% vs. 14%, p = 0.0047). 2. Postural coronal deformity was observed in 33% of patients. 3. Two patients exhibited true scoliosis (Cobb angle >10°)	0.95
Bae et al.7	2009	United States	Cross sectional	85	6–18 y	Coordination	PODCI*	Children with BPBI ages 6–18 y showed significantly lower PODCI scores for global function compared to age-matched pediatric norms. (p ≤ 0.01). No significant differences were found with regard to mobility or sports/physical function scores.	0.86
Kirjavainen9	2010	Finland	Cross sectional	112	0.4–13.2 mo	Posture, coordination	Mallet System, Gilbert score, Raimondi score	Diminished or asymmetrical motion during gait was associated with Mallet System score < 3 (35% vs. 14%, p = 0.0092), Gilbert score < 3 (31% vs. 10%, p = 0.0038), and Raimondi score < 4 (38% vs. 14%, p = 0.0047).	0.95
Grodner et al.26	2012	Poland	Cross sectional	30 (complete upper limb damage 15, incomplete upper limb damage 15)	7–12 y	Gait	Infotronic’s Ultraflex Computer Dyno Graphy gait analysis system	1. No difference in ground reaction forces was found between patients with complete vs. incomplete upper limb damage (0.32–1.35 vs. 0.35–1.49, p > 0.05) on both the injured and unaffected side 2. No difference in timing of gait phases was found in patients with complete vs. incomplete upper limb damage (0.13–0.63 vs. 0.13–0.66, p > 0.05) on both the injured and unaffected side	0.95
Ridgway et al.4	2013	United States	Retrospective Chart Review	32	1 w–16 y	Posture, balance, coordination	Documentation of physical examination and observation of functional tasks	1. 31 (97%) children across all levels of nerve injury exhibited postural control deficits. 2. 56% of children displayed trunk asymmetry.	0.91
Basic et al.21,#	2014	Bosnia	Not stated	5	ns	Posture	Clinical observation of posture	All patients (n = 5) exhibited thoracic scoliosis under 10°.	N/A
Bellows et al.25	2015	Canada	Cohort	39 (15 no deficits, 21 only shoulder or elbow deficit, 3 wrist and hand involvement)	5–15 y	Balance, coordination	BOT-2,† MABC-2,‡ and ASKp§	1. No significant difference in BOT-2 body coordination (p = 0.13), bilateral coordination (p = 0.19), and balance (p = 0.27) was found between the three subgroups. 2. No significant difference in MABC-2 Balance score (p = 0.47) and ASKp (p = 0.76) was found between the subgroups.	0.95
Uzun et al.30,#	2015	Turkey	Cohort	82 (40 BPBI, 42 healthy)	5–12 y	Balance	Standing on One Foot Test, Pedalo Balance Device	1. Compared to healthy age matched cases, there was a significant difference in non-dominant standing on one foot test (p = 0.002) and dominant standing on one foot test (p = 0.039). 2. Using Pedalo Balance Device, the difference in balance performance and vertical performance between two groups was significant (p = 0.047, p = 0.005)	N/A
Anguelova et al.31	2016	Netherlands	Cross sectional	19	3–8 y	Balance, coordination	Video recorded tasks: (a) walking heel-to-toe; (b) walking on the heels with small steps; (c) walking heel-to toe with eyes closed; (d) the same as task (c) but with a cognitive task	Children abducted affected arm less often than healthy arm in all four balance tasks (−1.38 [95% CI: −2.22, −0.53], p = 0.001) despite being able to do so on command.	0.95
Acaroz Candan et al.22	2019	Turkey	Cross sectional	50 (25 BPBI, 25 healthy)	2–6 y	Posture	Spinal mouse measurement, Active Movement Scale	1. Thoracic kyphosis was not significantly different than that of healthy age matched peers (31.20° vs. 26.56°, p = 0.118). 2. Lumbar lordosis was not significantly different than that of healthy age matched peers (25.12° vs. 24.52°, p = 0.786) 3. Frontal curvature was higher in children with BPBI (44% vs. 8%, p = 0.0001)	0.86
Ozdemir et al.27,#	2019	Turkey	Cohort	13	Mean age 9.37 y	Gait	Digital plantar-pressure analysis system to analyze foot pressure behaviour	1. Pre-swing duration, step length were higher on affected than non-affected side (p < 0.05) 2. Single limb support duration was lower on the affected side than non-affected side (p < 0.05) 3. Arm swing range was reduced on affected side (p < 0.05)	N/A
Calhoun32	2019	United States	Text and Opinion (Commentary on Acaroz Candan et al.22)	N/A	N/A	Posture	N/A	Suggestions for application of findings in “Assessment of Spinal Curvatures in Children with Upper Trunk OBPP”22 1. Emphasize avoiding compensatory postures and include various strategies to decrease trunk deformity secondary to compensatory movements 2. Treatment plan should include multiple strategies, including parent education, to address trunk asymmetry and compensatory movements.	N/A
Ozdemir et al.28	2020	Turkey	Cross sectional	29 (BPBI 19, health 10)	7–12 y	Gait	Foot pressure behaviour, arm swing motion using a pedobarographic and video camera	1. F1¶, ST**, LR††, Psw‡‡, SL§§, and MAE¶¶ were lower in non-affected side than in controls (p < 0.05) 2. Reduced max arm flexion angle was related moderately with decreased F2*** and SL (r: 0.23, p < 0.01, r: 0.23, p < 0.01, respectively)	0.82
Celik et al.24	2021	Turkey	Cross sectional	106	10–18 mo	Balance, coordination	Active Movement Scale, Mallet System, GMFM††† Sit Dimension, Sitting Assessment Scale	1. As GMFM sitting score increased, Active Movement scale values increased (0.41 < r < 0.70, p = 0.0001). 2. As Mallet System score values increased, GMFM sitting score increased (0.45 < r < 0.59, p = 0.001). 3. As SAS‡‡‡ total score increased, Active Movement scale increased (0.48 < r < 0.65, p = 0.0001). 4. As SAS total score increased, Mallet System scores increased in the impaired arm (0.51 < r < 0.63, p = 0.0001).	0.91

^*Pediatric Outcomes Data Collection Instrument.

^†Bruininks-Oseretsky Test of Motor Proficiency, Second Edition.

^‡Movement Assessment Battery for Children, Second Edition.

^§Activities scale for kids, performance version.

^#No full text available; data were extracted from abstract only.

^¶First peak-force.

^**Stance time.

^††Loading response.

^‡‡Pre-swing.

^§§Step length.

^¶¶Maximum arm extension angle.

^***Second peak-force.

^†††Gross Motor function measure.

^‡‡‡Sitting Assessment scale.

N/A = not applicable; ns = not specified.

Posture

Of the gross motor domains reviewed, posture was one of the most studied outcomes (n = 8, 50%) in all of the studies reviewed (Table 1). This is likely due to the visible asymmetry in upper limb length and size. The average quality of studies reporting postural outcomes was 0.92. Postural abnormalities were recorded either by observing signs of trunk asymmetry or pursuing more objective measurements by assessing for scoliosis using tools such as radiography and a spinal mouse device. Overall, postural asymmetry was observed in study participants, while incidence of scoliosis was less consistently documented.

Two studies observed postural asymmetry. A case series by Basic and Bogdani that outlined the outcomes of five patients with BPBI over 15 years reported that all patients developed thoracic asymmetry under 10°.²¹ Similarly, Ridgway and colleagues documented a visible trunk asymmetry in 56% (18 of 32) of their study participants.⁴

The effect of observed truncal asymmetry on spinal development was assessed in a study by Acaröz Candan and colleagues of 25 children aged 2–6 years old with upper trunk BPBI. Spinal mouse measurements were used to measure spinal curve deviations in the frontal and sagittal planes. Using a threshold of 10° of curvature, they found a higher incidence (44% vs 8%) and a larger degree (15.3 vs 11.5) of scoliosis in children with BPBI compared to the control group.²² This contrasts with other studies that have not found an association between BPBI and scoliosis. Kirjavainen et al’s study of 111 people with BPBI between the ages of 5–32 years old visually demonstrated a postural coronal deformity in 32% (36/111) of the participants.²³ However, only 2 of the 36 patients actually met the criteria for scoliosis (Cobb angle greater than 10°) on radiographs. As such, the incidence of scoliosis found in this study matches that of the general population. Another long-term follow-up study by Strombeck and colleagues of 70 participants echoes this finding as none of the participants displayed signs of scoliosis.⁸

Balance and coordination

Of the reviewed studies, eight (50%) discussed balance (n = 4, 25%) and/or coordination (n = 4, 25%), and had an average study quality of 0.93. Balance and coordination are critical for gross motor function, and deficits were observed in patients with BPBI relative to non-BPBI age-matched populations. Measuring balance and coordination ranged from general physical examination to the use of validated clinical scoring systems. The examinations were completed by physiatrists, physical therapists, and occupational therapists. Ridgway and colleagues’s study included 32 children with an isolated BPBI, and found that all but one of the participants demonstrated at least one deficit in postural control.⁴ Furthermore the deficits with the highest prevalence included decreased weight bearing through the pelvis, trunk, and extremities on the injury side (84%), rib cage and shoulder elevation with reach (59%), and trunk asymmetry (56%). Celik and colleagues found that trunk control in this population significantly correlates with the function of the injured upper extremity.²⁴ Specifically, there was a two-way relationship; truncal control scores deteriorated as injury severity increased, but upper extremity function also declined with increasing impairment of trunk control.

Additionally, when compared to healthy age-matched children, children with BPBI, regardless of injury side, exhibited a statistically significant difference in balance activities such as bilateral one-legged balance.²⁴ Similar balance deficits were found by Bellows and colleagues using two different scoring systems: subscales of the Motor Assessment Battery for Children (MABC-2) and the Bruininks–Oseretsky Test of Motor Proficiency (BOT-2).²⁵ The MABC-2 observes balance when standing on two feet, one foot, on a balance beam, walking forward in a line, and hopping. Most of the study participants (66.7%) scored below average in these tasks, and the mean BOT-2 scores replicated this finding.

Gait

Across the selected studies, gait was discussed by four (25%) papers that had an average study quality of 0.91. Gait was generally measured through two methods. The first included a more subjective measurement through observation of gait pattern²³ and the second was a more objective method using a device that measures plantar pressure through the various gait phases.^23,26–28 All four studies agreed that the gait pattern in this population was clearly asymmetrical on an observed gait exam. One study by Grodner and colleagues, without a control group, did not find a statistically significant asymmetry in ground reaction force between the injured and non-injured sides.²⁶ However, Ozdemir and colleagues found that when comparing foot plantar pressure between children with BPBI to healthy children of similar ages, there was reduced single-leg stance duration on the injury side.²⁷ In addition to this, first peak force was increased on the affected side compared to the unaffected side. Ozdemir and colleagues also found that children with BPBI have longer single-leg and terminal stance time on both their affected and non-affected sides compared to an unaffected control group.²⁸

Discussion

The three aspects of gross motor function that were the main focus in this study were posture, coordination and balance, and gait.

Postural abnormalities

The main theory describing the cause of postural abnormalities is based on the effects of limb injury on the spinal column. Specifically, injuries may result in an imbalance in the upper trunk musculature which ultimately results in compensatory spinal positions; asymmetry causes lumbar lordosis and excessive vertebral rotation to compensate for the observed unilateral bowing in body posture.²⁹

Based on the current literature, it is more likely that people with BPBI have a visual truncal asymmetry and postural deformity secondary to upper limb imbalance rather than true scoliosis.^4,23,29 It is unclear whether there is an increased incidence of scoliosis in this population. Some researchers would argue that the rate presented by Acaröz Candan and colleagues is higher than the actual incidence when compared to the findings of other studies.²² This is also acknowledged by the authors themselves who suggest that the use of a Spinal Mouse may not be as accurate when participants have insufficient shoulder external rotation and abnormal scapular position, as is the case in many patients with BPBI.

Clinical implications of these findings suggest the need for increased awareness of scoliosis in this population which may lead to focused screening as the children age. In addition, emphasis should be placed on avoiding compensatory postures that exacerbate upper trunk imbalance. Lastly, focusing rehabilitation strategies on arm, scapular, and trunk strength should be implemented given the correlation between functional strength and trunk stability.²⁴

Balance and coordination

Balance and coordination are two complementary gross motor functions required for participation in most daily and recreational activities. Postural control is a term often used interchangeably with balance. Truly, it represents the combination of balance and coordination required for everyday movement; it is the ability to maintain a controlled midline posture while moving against gravity.

Based on our findings, children with BPBI exhibit some form of postural control deficit. BPBI often causes muscle atrophy and asymmetry, resulting in impairment of movement essential for the development of postural control: prone forearm weight-bearing and uneven weight transfer in infants learning to turn, crawl, and pull to stand.^4,29,30 Thus, we hypothesize that as children get older, postural control impairments are further exacerbated since compensatory movements to perform ADL cause asymmetric loading to the affected arm, joints, and trunk.

Another theory suggests there may be a central component to impairment. In one study, children with BPBI could abduct their affected arm to 90° on request. However, during balance tasks, they abducted their affected arm much less than their unaffected arm despite previously demonstrating their ability to do so. Hence, while upper limb asymmetry may be the leading cause of balance deficits, diminished central programming may also be a component.

Gait

Lastly, this review found that gait disorders can also present secondary to the upper limb asymmetry seen in BPBI. Arm swing motion is essential in gait as it reduces trunk rotation, providing stability in the lower limbs. However, with BPBI, arm swing is often reduced, asymmetrical, or even absent. As a result, there may be pelvic rotation differences which subsequently cause changes to the overall gait pattern.

The studies in this review indicated increased length of stance phases bilaterally for some people with BPBI compared to people without BPBI, and may reflect the added effort needed to facilitate stability against the asymmetry in arm swing motion. Moreover, the difference in first peak vertical force between the affected and unaffected sides is likely due to the reduced arm range of motion in BPBI since adequate arm extension is required to absorb the first peak vertical force. Taken together, these factors contribute to the reported relative gait instability in BPBI.

This study has limitations. Despite approaching the study with an open and broad selection method, only 16 studies matched our criteria. The authors cannot be certain that all relevant articles were identified and included. Furthermore, where full-text articles were unavailable or inaccessible, abstracts were used instead. This may have limited the thoroughness of the information reviewed. Some studies could not be translated into English for use and were not included. As such, there was limited information to draw hypotheses and recommendations from.

Conclusion

Overall, our study suggests that people with increased severity of BPBI experience significant changes to gross motor function outside of the affected arm. Postural deficits in people with significant BPBI can be prominent, and the compensatory movements required for independent function may exacerbate the deficits. Balance and coordination impairment is also seen in this population and is a result of both limb asymmetry and potentially central motor programming. Together, abnormal posturing, balance, and coordination play a role in developing an abnormal gait pattern. Asynchronous arm swing during gait is apparent; however, when this asymmetry combines with posture and balance deficits, the result is gait instability.

Children with BPBI would benefit from a broader approach to rehabilitation as their functional deficits go beyond the injured extremity. Examples of this can include: postural education and cueing, sport specific training according to the child’s interests, incorporating both arms into symmetrical arm swing when walking or running, dynamic and static balance exercises, core exercises for postural stability, and practising two-handed ball skills. Adults with BPBI have reported increasing disability with age,¹¹ which may be preventable or minimized by a more holistic approach to managing their injury throughout their lifespan.

Key Messages

What is already known on this topic

Studies have focused on the effect of brachial plexus birth injury (BPBI) on the function of the affected arm, which can present with varying degrees of weakness and asymmetrical movement. Depending on the extent and location of injury, there is commonly some degree of functional impairment.

What this study adds

This study synthesizes current literature on the effects of BPBI on posture, balance and coordination, and gait. The results suggest that people with increased severity of BPBI experience significant changes to these domains of gross motor function outside of the affected arm throughout their lifetime, demonstrating the need for a broader approach to rehabilitation.

Appendix 1.

Key words for MEDLINE search performed on April 27, 2021

1. Brachial Plexus/in [Injuries]

2. brachial plexus neuropathies/ or neonatal brachial plexus palsy/

3. Paralysis, Obstetric/

4. Erb* Palsy.tw,kf.

5. Erb* paralysis.tw,kf.

6. (brachial plexus birth adj2 (palsy or injur*)).tw,kf.

7. ((birth or obstetric) adj2 brachial plexus).tw,kf.

8. (birth related brachial plexus adj2 (palsy or injur*)).tw,kf.

9. ((birth or neonat* or obstetric or obstetrical) adj2 brachial plexus).tw,kf.

10. or/1-9

11. Gait Analysis/ or Gait/ or Gait Disorders, Neurologic/

12. ((gait or run* or walk* or arm swing*) adj2 (asymmetr* or symmetr*)).tw,kf.

13. “Range of Motion, Articular”/

14. (range of motion adj3 (articular or leg or arm)).tw,kf.

15. psychomotor performance/ or motor skills/ or “task performance and analysis”/

16. atypical movement*.tw,kf.

17. (movement or movement pattern).tw,kf.

18. ((body or upper body) adj2 kinematics).tw,kf.

19. coordination.tw,kf.

20. body coordination.tw,kf.

21. ((motor or psychomotor) adj2 (skill* or performance)).tw,kf.

22. motor proficiency.tw,kf.

23. Postural Balance/

24. Ataxia/

25. balance.tw,kf.

26. postural control.tw,kf.

27. Posture/

28. posture.tw,kf.

29. Asymmetr* posture.tw,kf.

30. postur* development.tw,kf.

31. Scoliosis/

32. scoliosis.tw,kf.

33. ((spine or spinal) adj2 (curvature or asymmetr*)).tw,kf.

34. trunk asymmetr*.tw,kf.

35. Spine/ab, gd [Abnormalities, Growth & Development]

36. ((spine or spinal) adj2 abnormalit*).tw,kf.

37. or/11-36

38. 10 and 37