Hammersmith Infant Neurological Examination clinical use to recommend therapist assessment of functional hand asymmetries

Abstract

Purpose:

To determine whether asymmetry scores derived from the Hammersmith Infant Neurological Examination (HINE) can provide cut-off scores for recommending in-depth assessment of upper extremity functional deficits by therapists using the Hand Assessment for Infants (HAI).

Methods:

Observational study in a clinical laboratory with the HINE and the HAI administered concurrently to 101 infants 3-12 months corrected age developing typically or atypically. Predictive value of HINE asymmetry scores for atypical HAI was determined.

Results:

Total HINE asymmetry score ≥4 had 100% sensitivity and ≥88% specificity for identifying infants with an asymmetric HAI score of ≥3 point difference between hands.

Conclusions:

For infants receiving a total HINE asymmetry score of 4 or greater, referral to therapists for HAI assessment may be beneficial to precisely evaluate function and determine the need for targeted upper extremity interventions.

INTRODUCTION and PURPOSE

Targeted interventions such as constraint-induced movement therapy and bimanual therapy are widely used to drive neuroplasticity and aid recovery following neurologic insult with upper extremity dysfunction, including cerebral palsy (CP).¹ These interventions are effective in children with unilateral or bilateral CP with one upper extremity more affected than the other,¹ with new trials investigating use in younger children and infants.^2–4 Infants developing typically use both hands equally during the development of reach and grasp over the first year of life, though the patterns of usage change with different stages of development,^5,6 and early hand preference or hand disregard in infants is an indicator of asymmetric upper extremity dysfunction.⁷ Evidence supports maximal neuroplasticity early in life with mechanisms unique to the developing brain.^8,9 Therefore, early identification of infants who may benefit from targeted upper extremity interventions is thought to optimize functional recovery.¹⁰ However, most infants who need motor evaluation are identified in general pediatric settings with limited access to psychometrically sound standardized assessments and specialized providers (e.g., therapists). Furthermore, functional impairments may be subtle, particularly in young infants, and the tools to identify them are currently limited.

The Hand Assessment for Infants (HAI) is a criterion-based assessment to evaluate quality and frequency of functional hand use in infants 3-12 months corrected age (CA), validated for measuring bilateral hand use and quantifying hand asymmetry in infants at risk for unilateral CP.^11,12 The HAI is a play-based assessment with unimanual and bimanual test items. Scores for the unimanual items are summed separately for right and left hands to obtain each hand sum scores, and an asymmetry index is derived as the percent difference between each hand sum scores. Overall performance incorporates bimanual items and is scored as both hands measure. Growth curves and age norms have been developed from a cohort of infants with typical development.¹²

The HAI is particularly suited for detecting and quantifying early clinical signs of hand asymmetry. The inclusion of a quality of movement assessment makes the HAI more useful for identifying early upper extremity deficits than other commonly used infant motor assessments. The Alberta Infant Motor Scale (AIMS) and the Test of Infant Motor Performance (TIMP) assess general motor development, but do not include fine motor scales. The Bayley Scales of Infant and Toddler Development, 4th Edition (Bayley-III) and the Peabody Developmental Motor Scales, Second Edition include fine motor scales, but do not measure the quality of task performance. Additionally, they do not separately assess each upper extremity, instead allowing children to use their more capable hand to complete tasks.¹³

The HAI currently has the best psychometric properties for assessing infant hand function and asymmetry, making it a useful measure for evidence-based protocols and measuring treatment effects.¹² However, required certification from infrequent training opportunities, as well as time-consuming assessment and scoring, limit its implementation in fast-paced clinical settings, where the majority of infants at high risk for developmental delays and impairments are monitored. Therefore, to optimize referrals to HAI-trained therapists, a method for identification of infants who are candidates for more in-depth assessment of upper extremity function is needed.

The Hammersmith Infant Neurological Examination (HINE) is a widely-available, easily implemented standardized exam for children 2-24 months CA, with published optimality scores for infants at different ages.^14,15 Clinicians score children on 26 observed and elicited items, many of which are elements of a general examination for high-risk infants. In addition to assessing cranial nerves, muscle tone, and deep tendon reflexes, clinicians place or move children into different positions and observe their static or reactive postures. No specialized equipment is needed. Importantly, the HINE is a low-resource tool with relative ease-of-administration and good interrater reliability, even among less-specialized clinicians.¹⁶ It requires approximately 10 minutes to perform and can easily be incorporated into standard surveillance visits or therapy evaluations without adding to the visit length, an important factor in pediatric clinics.¹⁷ Formal training and certification are not required to use the HINE in clinical practice, and self-study videos and score forms are available online at no cost.¹⁸ Free in-person training is available, and is recommended when feasible to optimize reliability, or when using the HINE for research. The HINE total score has good predictive value for CP in high-risk infants at 3 months CA, with a cut-off score of 57.^19,20 A total HINE asymmetry score (HINE AS) is calculated by summing the number of items with clinical differences between right and left sides.¹⁷ Among children with HINE total scores in the normal range, total HINE AS >5 at 9 months CA differentiates children with hemiplegia from those with typical development, but does not provide information about the quality or degree of impairment of upper extremity function.²¹

Our aim was to determine whether HINE asymmetry scores could be used by pediatric providers (including physicians, nurse practitioners, and therapists) to identify infants who may benefit from in-depth assessment of upper extremity function using the HAI. Better screening may inform clinical decision-making regarding referral to targeted developmental interventions and specialty therapists, and eventually drive improved access to specialized training for all early-intervention therapists. Infants in our hospital’s high-risk infant follow-up clinic receive the HINE as standard of care at every visit, but the resource-intensive nature of the HAI makes universal implementation impractical in this high-volume setting. We therefore investigated associations between HINE scores performed by a pediatric practitioner and HAI asymmetry scores determined by 2 trained therapists.

METHODS

Design and Participants

This was an observational study of infants aged 3-12 months (age corrected for pre-term infants, n=31) developing typically (n=50) or atypically (n=51) assessed in a clinical research laboratory setting between 6/11/2018 and 5/24/2019. Atypical development was defined by scores greater than 1 SD below the mean on a clinical motor assessment (e.g., AIMS, TIMP, Bayley-III)²² or by abnormal HINE as defined by published optimality scores for total score (<73 at 9-12 months CA, <70 at 6 months CA, and <67 at 3 months CA)^14,15 or asymmetry score (>5).²¹ These infants were recruited from the hospital-based high-risk infant follow-up clinic, stroke clinic, and outparticipant physical and occupational therapy departments. Exclusion criteria were inability to tolerate a 15-minute play session (i.e., medically fragile) or inability to visually track a brightly colored object from midline in a 45° arc to each side. A total of 116 infants developing atypically were identified as eligible during the enrollment period; of these, 55 were enrolled, 26 declined to participate, and 35 could not be contacted. 4 infants were excluded after enrollment (3 due to visual impairments, and 1 due to technical difficulties resulting in the loss of the HAI video recording). Nineteen participants had neuroimaging showing bilateral brain injury, and 11 had unilateral brain injury. Sixteen participants were diagnosed with CP (GMFCS I-IV) as of 5/29/2020 (5 with hemiplegia, 5 with asymmetric quadriplegia, 2 with symmetric quadriplegia, 1 with asymmetric diplegia, 1 with symmetric diplegia, and 2 with unspecified type). 5 participants were classified as “high-risk for CP.”²³ The remaining infants with atypical development had non-specific diagnoses, e.g., abnormal tone and/or developmental delay.

Infants with typical development were recruited from clinics and hospital employee families via convenience sampling (infants were enrolled as parents responded to our verbal or written requests for participants) and were age-matched to account for age-related changes in performance on both the HINE and the HAI. Infants in this cohort had no history of birth complications, developmental delay, neurological abnormalities, or prematurity (defined as <37 weeks gestation; 1 infant had a gestational age of 36 weeks, 6 days). The hospital’s Institutional Review Board approval was obtained for the use of human participants.

Measures

Assessments were administered on the same day with assessors blinded to each other’s scores. The HINE was administered by a general pediatrician who is a HINE trainer. The HAI was administered by 1 of 2 HAI-certified, licensed therapists (one physical therapist and one occupational therapist), both with extensive experience in pediatric therapy. Both therapists undertook additional post-certification HAI training and achieved consensus on 5 scores with experienced examiners. Therapists had excellent intra- (0.961) and inter-rater (0.98) reliability for the present study (average measure intraclass correlations determined using 2-way mixed effect models). Both HAI asymmetry index and point difference between hands (absolute value of difference between each hand sum scores) were calculated.¹¹ In addition to the conventional HINE AS (asymmetry total from all 26 items),¹⁷ we grouped HINE items into clusters to create the upper body score (10 items) and arm score (7 items) (Figure 1), from which the HINE upper asymmetry score (Upper AS) and arm asymmetry score (Arm AS) were calculated. The rationale for these item clusters was to allow comparison of the predictive value of neurological status of the whole body, versus that of the upper body or arm alone, with regard their relationship to upper extremity dysfunction. The HINE was conducted and scored per standard procedures; scores for item clusters were extracted separately for analysis.

Figure 1.

HINE item clusters

Analysis

Participant characteristics were compared by HAI asymmetry status using Wilcoxon rank sum tests, chi-square, or Fisher’s exact tests. Non-parametric statistics were used to compare cohorts as the distribution of the data was not symmetric; this was true of all variables in the study.

Neither an atypical HAI asymmetry index nor difference between each hand sum scores had been defined prior to this study.¹² One of the definitions of atypical HAI we created to test our screening tools was ≥3 points difference between hands, which was identified in only 2% of a previously studied cohort of infants developing typically.¹² We also compared ≥2 points difference between hands, a more sensitive cut-off designed to include children with very subtle asymmetries.

Univariate logistic regression with receiver operating characteristic (ROC) curve analysis was used to evaluate the association between HINE and HAI, and Youden’s J statistic (J= Sensitivity + Specificity −1) was used to derive optimal threshold values of HINE for differentiation between typical versus atypical HAI. HINE threshold performance was assessed using sensitivity, specificity, and area under the ROC curve (AUC) derived separately for the full cohort versus infants >4 months CA to account for age-dependent differences in upper extremity function in very young infants. A “combined” tool was evaluated to determine whether exceeding the threshold value for any of the 3 HINE asymmetry scores (HINE AS, Upper AS, or Arm AS) better predicted abnormal HAI than individual scores considered alone.

RESULTS

Participant characteristics

The cohort (n=101) was 49% female with a median GA at birth of 39 weeks (interquartile range, IQR [34.7-40]) and a median CA at testing of 7.6 months [IQR 5.3-9.7]. GA was significantly lower in the cohort of infants developing atypically (p<.001), but mean CA at testing did not differ between groups (p=.99). Both the HAI both hands measure and the HINE total scores were significantly lower in the cohort of infants developing atypically versus those developing typically (p<.01), whereas the HINE asymmetry scores, the HAI asymmetry index, and the HAI difference between hands were significantly higher (p<.001) (Table 1).

Table 1:

Summary of Cohort

	All (n=101)	Developing atypically (n=51)	Developing typically (n=50)	P
Female, n (%)	49 (49)	20 (39)	29 (58)	.06
GA at birth, weeks	39 (34.7,40)	34.7 (30,39)	40 (39,40.1)	<.001
CA at assessment, months	7.6 (5.3,9.7)	8.0 (5.0,10.0)	7.0 (5.3,9.4)	.33
CA at assessment, months, mean±SD	7.5±2.5	7.6±2.6	7.4±2.5	.99
HINE Total Score	69 (61.5,73)	61.5 (52,68)	71.75 (69,74)	<.001
HINE Asymmetry Score	1 (0,4)	4 (1,8)	0 (0,1)	<.001
HINE Total Upper Score	28 (24,31)	25.5 (20,28)	31 (28,32)	<.001
HINE Upper Asymmetry Score	0 (0,2)	2 (1,4)	0 (0,0)	<.001
HINE Arm Asymmetry Score	0 (0,1)	1 (0,4)	0 (0,0)	<.001
HAI Both Hands Measure	75 (62,84)	70 (45,82)	77 (72,88)	.002
HAI Sum Left Hand	22 (19,23)	21 (15,23)	23 (22,24)	<.001
HAI Sum Right Hand	22 (19,23)	20 (17,23)	23 (22,24)	.002
HAI Asymmetry Index	0 (0,5.88)	4.55 (0,25)	0 (0,4.35)	<.001
HAI Difference Between Hands	0 (0,1)	1 (0,5)	0 (0,1)	<.001
Difference ≥2, n (%)	25 (25)	21 (41)	4 (8)	<.001
Difference ≥3, n (%)	18 (18)	18 (35)	0 (0)	<.001

Data are median (IQR) unless noted. GA, gestational age; CA, corrected age; HINE, Hammersmith Infant Neurological Examination; HAI, Hand Assessment for Infants

Among the entire cohort, 25 infants (25%) had ≥2 points difference between hands, and 18 (18%) had ≥3 points difference between hands (Table 1). The point difference between hands ranged from 0-23 for infants developing atypically, and 0-2 for infants developing typically. HAI asymmetry index scores ranged from 0-100% for infants developing atypically, and 0-11.1% for those developing typically. Although the majority of infants meeting our definitions of atypical HAI were within the cohort of infants developing atypically, 4 infants in the cohort with typical development had a 2-point difference between hands, meeting our less rigorous atypical HAI definition. As expected from the design, no infants in the typically developing cohort had ≥3 points difference between hands. Summary characteristics of infants diagnosed with asymmetric CP (n=11) are in Supplemental Digital Content.

GA at birth was significantly lower among infants with an atypical HAI difference between hands (either definition) compared to those with typical scores (p<.05) (Table 2).

Table 2:

Comparison of subject characteristics by HAI cut-offs

HAI Difference Between Hands	<2 (n=76)	≥2 (n=25)	P
Female, n (%)	37 (49)	12 (48)	.95
GA at birth, weeks	39 (36.9,40)	37 (31.7,39)	.03
CA at assessment, months	7.8 (5.3,9.8)	6.9 (4.9,9.1)	.42
HINE Total Score	70 (65.25,74)	60.5 (52,67)	<.001
HINE Asymmetry Score	0 (0,2)	6 (4,9)	<.001
HINE Total Upper Score	29.3 (26,32)	25.5 (20,27.5)	<.001
HINE Upper Asymmetry Score	0 (0,1)	3 (2,5)	<.001
HINE Arm Asymmetry Score	0 (0,1)	2 (1,5)	<.001
HAI Difference Between Hands	<3 (n=83)	≥3 (n=18)
Female, n (%)	42 (51)	7 (39)	.37
GA at birth, weeks	39 (36.9,40)	35.5 (31.6,38.7)	.03
CA at assessment, months	7.4 (5.3,9.7)	7.8 (4.9,9.2)	.90
HINE Total Score	70 (65,74)	55.8 (50,62.5)	<.001
HINE Asymmetry Score	0 (0,2)	7 (5,10)	<.001
HINE Total Upper Score	29 (26,32)	21 (17,26)	<.001
HINE Upper Asymmetry Score	0 (0,1)	3.5 (2,6)	<.001
HINE Arm Asymmetry Score	0 (0,1)	3 (1,6)	<.001

Data are median (IQR) unless noted. HAI, Hand Assessment for Infants; GA, gestational age; CA, corrected age; HINE, Hammersmith Infant Neurological Examination

Forty-nine of 51 infants developing atypically were referred to physical and/or occupational therapy prior to 12 months CA by their primary care or high-risk infant follow-up clinic providers. The research team recommended physical therapy for 1 additional infant based on the results of the study assessments, but referral status could not be confirmed due to the family moving to another state.

Asymmetry score performance

HINE AS ≥4 was the optimal threshold and had the highest predictive value for both atypical HAI definitions for the entire cohort and for infants >4 months CA (Table 3). HINE AS ≥4 had 100% sensitivity, 88% specificity, and an AUC of 0.940 for the full cohort and 100% sensitivity, 90% specificity, and an AUC of 0.948 for infants >4 months CA for predicting abnormal HAI defined by point difference between hands of ≥3 (Figure 2). Sensitivity was lower (79-80%) and specificity was similar (89-91%) for predicting ≥2 points difference between hands. Compared to HINE AS, predictive values for Upper AS, Arm AS, and the combined tool (“combined”) for atypical HAI were significantly lower in the full cohort (p<.05).

Table 3:

HINE Asymmetry Score Performance

	Threshold	Sensitivity	Specificity	AUC (95% CI)	P
HAI Difference Between Hands ≥3 Points
Full cohort (n=101)
HINE Asymmetry Score	4	100	88	0.940 (0.905,0.975)	ref
HINE Upper Asymmetry Score	2	94	81	0.876 (0.807,0.945)	.04
HINE Arm Asymmetry Score	1	94	70	0.822 (0.748,0.895)	<.001
	Combined	100	67	0.837 (0.787, 0.888)	<.001
>4 months CA (n=93)
HINE Asymmetry Score	4	100	90	0.948 (0.914, 0.982)	ref
HINE Upper Asymmetry Score	2	94	83	0.886 (0.815, 0.958)	.06
HINE Arm Asymmetry Score	1	94	71	0.828 (0.751, 0.905)	.001
	Combined	100	70	0.851 (0.799, 0.902)	<.001
HAI Difference Between Hands ≥2 Points
Full cohort (n=101)
HINE Asymmetry Score	4	80	89	0.847 (0.760,0.935)	ref
HINE Upper Asymmetry Score	2	76	82	0.788 (0.692,0.884)	.02
HINE Arm Asymmetry Score	1	80	71	0.755 (0.672,0.852)	.01
	Combined	84	68	0.762 (0.672,0.852)	.01
>4 months CA (n=93)
HINE Asymmetry Score	4	79	91	0.853 (0.764, 0.942)	ref
HINE Upper Asymmetry Score	2	75	84	0.796 (0.698, 0.895)	.03
HINE Arm Asymmetry Score	1	79	73	0.760 (0.662, 0.858)	.01
	Combined	83	71	0.774 (0.681, 0.867)	.01

HINE, Hammersmith Infant Neurological Examination; HAI, Hand Assessment for Infants; AUC, area under the (ROC) curve; CI, confidence interval; CA, corrected age

Bold text denotes best asymmetry score performance for each definition of atypical HAI.

“Combined” row shows the performance when abnormality on any one of the three HINE Asymmetry Scores (HINE Asymmetry Score, HINE Upper Asymmetry Score, or HINE Arm Asymmetry Score) rather than each individually is used to identify an infant at high-risk of having an atypical HAI.

Threshold values are based on Youden’s J (J= Sensitivity + Specificity − 1).

Figure 2.

ROC curves for HINE asymmetry score performance, using HAI difference between hands ≥3 points

DISCUSSION

The HINE, a low-resource standardized neurological examination used in developmental surveillance, can identify infants needing more comprehensive assessment of upper extremity asymmetry by therapists trained in the more resource-intensive HAI. The total HINE AS may be used to identify and refer infants at risk for asymmetric upper extremity dysfunction, as defined in this study by a HAI point difference between hands of ≥3. In the study cohort, a HINE AS cut-off of 4 was highly sensitive (100%) and specific (≥88%). Among infants developing typically in a previously studied cohort, 20% had 1-2 points difference between hands and 78% had no difference.¹² Our results were in agreement, as none of the infants developing typically in our study had a point difference between hands >2.

Optimality scores for HINE total scores miss some children with hemiplegia, who may achieve scores in the normal range for their age.¹⁹ Rather, the HINE AS may be used to distinguish infants with hemiplegia from those developing typically.²¹ The present study aimed to use HINE AS to predict risk for functional impairment of the upper extremities, regardless of diagnostic outcome, and identified a lower threshold with good sensitivity and specificity for all infants 3-12 months CA. Published research on HINE AS examined only threshold at 9 months corrected age²¹; for some infants, this may mean missing a time period of opportunity for early intervention. Additionally, 4 participants in our sample who received a diagnosis of asymmetric cerebral palsy had a HINE AS ≤5, including 2 with HINE AS=4. Both of these participants were under 9 months CA and had an asymmetric HAI (difference between hands of 7), and may have been ruled out for further assessment of upper extremity asymmetries if the previously defined higher HINE AS threshold (AS >5)²¹ had been used.

Early detection of upper extremity dysfunction in infants can be particularly challenging, as early signs of asymmetry may be subtle.^7,24 Generally, infants do not develop consistent reach until approximately 4 months of age and continue to demonstrate a high degree of inaccuracy for a few months.²⁵ Infants at high risk for CP demonstrate an abnormal developmental trajectory for upper extremity function, with differences in quality of movement, kinematics, and peak performance compared to typically developing peers.⁷ Reach asymmetry appears to be one of the earliest signs of upper extremity dysfunction in high-risk infants and can be detected as early as 2-3 months of age.^7,26 Furthermore, reach development is dependent on postural stability and the ability to use anticipatory postural adjustments, which are impaired in high-risk infants.²⁷ Therefore, an infant’s overall neurological status has an impact on their ability to functionally use their upper extremity. Quantitative evaluation of hand function to determine eligibility for targeted intervention strategies is more important than ever, as the evidence base for the efficacy of interventions for young children with asymmetric upper extremity dysfunction grows.^2–4

The HAI assesses both development of hand use and presence of pathological movements and performance. Scores strongly correlate with age, with older infants expected to perform better overall.¹² In this study, HINE AS performed well in the full cohort, and also for infants >4 months CA. Unfortunately, asymmetry score performance of infants ≤4 months CA could not be evaluated separately due to the small number of infants in this age range (n=8). Further investigation is needed to determine whether the HINE is effective in discriminating atypical HAI in very young infants at 3-4 months of age.

Arm AS and Upper AS, which we initially hypothesized would be more specific measures of upper extremity neurologic function as compared to the total HINE AS, were less predictive of asymmetric HAI. This could be due in part to the small range of possible values for the Arm AS and Upper AS, making cut-off calculations less precise. Additionally, this finding may be a reflection of the role that whole-body postural control and nervous system physiology and status play in upper extremity function, particularly in the developing infant.^27,28

While many studies have focused on detection and intervention for unilateral or asymmetric CP in infants and children, early upper extremity intervention is also indicated for infants with bilateral deficits, but without significant asymmetries. Low HINE total scores indicate risk for neurologic disorders, including but not limited to CP, and may suggest the need for further assessment and monitoring of upper extremity function and referral to physical and occupational therapies. The HAI provides a measure of hand function in relation to age and is useful for more in-depth assessment following a suspect neurologic exam. Future studies could investigate the predictive value of HINE total scores for abnormal HAI each hand or both hand sum scores, using published age normative values.¹²

While this study provides a useful cut-off score for investigation of asymmetric upper extremity dysfunction, providers should continue to make referral decisions based on clinical reasoning, taking into account parent report of movement difficulties or asymmetries, neuroimaging, and other clinical observations. The Infant Motor Activity Log (IMAL), a validated parent-reported measure of hand performance (as opposed to the HAI, which measures capacity), may prove to be a useful complement to the HAI for therapists assessing how often and how well an infant uses their more-affected hand in the home environment.²⁹

The HINE AS is an accessible clinical tool to direct participants from general medical or therapy clinic settings to more in-depth assessment of upper extremity asymmetries, in combination with other assessment tools and clinical reasoning. The HINE is included in international guidelines as a first-line recommended tool (in combination with MRI) for detection of CP in infants <5 months CA.²³ The HINE has been successfully implemented as standard of care in a network of high-risk infant follow-up programs in the United States, demonstrating its feasibility and efficacy in clinical settings.^17,30 In contrast, the HAI requires specialized training and certification to administer and score, and is significantly more costly in terms of time and resources for both training and administration. Both the HINE and the HAI have established validity and reliability for use with high-risk infants.

Limitations

The cohort of infants developing atypically was recruited primarily from our hospital’s high-risk infant follow-up clinic based on atypical motor assessment or neurological examination (HINE). Therefore, this cohort is not representative of all high-risk infants, some of whom test within the normal range on motor and neurological exams. As the prevalence of delayed motor development and abnormal neurological status in our sample was likely higher than might be encountered in clinical practice, generalizability is impacted and results of this study should be interpreted with caution.

Children with more mild forms of CP, including some with hemiplegia, may score within the normal range on motor and neurological examinations, especially in early infancy; therefore, inclusion criteria for the cohort of infants developing atypically may have excluded this group. It is also possible that some of these infants were included in the cohort with typical development. The majority of infants in this study with abnormal HINE scores and functional hand differences on the HAI were diagnosed with CP at <2 years CA, consistent with efforts to lower the age at diagnosis.²³ Although not a focus of this study, the incidence of CP in the study cohort reported here may be underestimated if additional study participants are later diagnosed with CP.

CONCLUSIONS

For pediatric care providers using the HINE, a HINE AS ≥4 in infants 3-12 months CA suggests the need for a more in-depth assessment of upper extremity functional asymmetries by a specialized therapist. In contexts where HAI administration and scoring of all infants is not feasible (e.g., limited time or resources, lack of trained therapists), the HINE has value due to greater accessibility. HINE asymmetry scores can contribute to clinical decision making when determining the need for referrals for further assessment or targeted interventions.

WHAT THIS ADDS TO THE EVIDENCE.

Pediatric care providers working with young infants could consider using the total HINE asymmetry score to identify infants needing referral to therapists for more in-depth assessment of upper extremity function. In particular, infants 3-12 months corrected age with HINE asymmetry scores ≥4 may benefit from functional assessments and targeted upper extremity intervention to address asymmetries.