2 all ﬁngers around the examiner’s ﬁnger, which is composed of two phases: ﬁnger closure and clinging. The latter occurs as a reaction to the proprioceptive stimulation of the tendons of the ﬁnger muscles due to slight traction subsequent to the application of pressure to the palm [21, 22]. The plantar grasp reﬂex is elicited by pressing a thumb against the sole of a foot just behind the toes [6, 18, 23]. The state and position are the same as for eliciting the palmar grasp reﬂex. The response of the reﬂex consists of ﬂexion and adduction of all the toes. Milani-Comparetti and Gidoni [24] devised another method for eliciting the plantar grasp reﬂex. They tested for the presence of the reﬂex by placing the infant in a supported standing position, stimulating the soles of the feet by ﬂoor contact, looking for plantar ﬂexion of the toes. Determination of whether the response of the hands and feet is a true reﬂex or a voluntary grasping movement can be diﬃcult in older infants. An examiner should test several times with an appropriate interval between the tests, carefully observing the infant’s behavior [8, 25]. 2.2. Clinical Signiﬁcance 2.2.1. Responses in Normal Infants. The grasp reﬂexes of the hands and feet in normal term infants have been studied by several authors. Their results were fairly consistent regarding the times of the appearance and disappearance of the reﬂexes. The palmar grasp reﬂex and the plantar grasp reﬂex can be elicited in all infants during the ﬁrst 3 and 6 months of age, respectively. Thereafter they decrease along with the intensity of the responses, usually disappearing by 6 and 12 months of age, respectively [6, 7, 25–27]. The disappearance of the reﬂexes is signiﬁcantly related to the commencement of the voluntary use of hands or standing [28, 29]. In contrast to the studies involving term infants, those involving preterm infants have been few. Allen and Capute [1] examined 47 infants and concluded that the intensity of the primitive reﬂexes including the grasp reﬂexes of the hands and feet in the preterm infant at term (40 weeks of PCA) was similar to that in full-term newborns reported in the literature. We analyzed the data for 834 infants (332 term and 502 preterm) who were later conﬁrmed to be normal on follow-up examination between ages 3 to 9 years [6]. The primitive reﬂex responses of preterm infants were compared with those of term infants, according to corrected age as to expected birth date. No diﬀerence was evident in the changes in responses including that of the plantar grasp reﬂex between term and preterm infant groups throughout the ﬁrst year of life. 2.2.2. Abnormal Responses. In general, a primitive reﬂex in infants is regarded as abnormal when it is absent or dimin- ished during the period it should be actively elicitable or lasts beyond the normal age limit for its disappearance. An exaggerated reﬂex can also be abnormal. The response of the palmar grasp reﬂex may be less intense during the ﬁrst and second days after birth [18]. The absence of this reﬂex usually reﬂects peripheral (i.e., root, plexus, or nerve) or spinal cord involvement, especially regarding asymmetrical International Journal of Pediatrics responses [18, 30, 31]. However, lesions of the upper brain structures also can aﬀect the response. The response may be increased and retained longer, compared with that in normal infants, on the aﬀected side(s) of the upper limb(s) in infants with spastic hemiplegia or quadriplegia, whereas it is very weak in infants with cerebral palsy (CP) of the athetoid type [26, 27, 32]. The clinical value of the plantar grasp reﬂex in infants has been investigated in more detail than that of the palmar grasp reﬂex. In 1932, Brain and Curran [33] reported two cases showing no response at the age of 6 months who both suf- fered from bilateral marked spasticity and one case showing a vigorous response at the age of 2.5 years who suﬀered from congenital choreoathetosis. They also investigated the reﬂex in 59 patients with Down’s syndrome, ranging in age from 1 to 45 years. They discovered that up to age 20 years, the response was present in 25 of 42 patients and, after age 20 years, in 3 of 17. We analyzed 617 infants (291 term and 326 preterm) whose plantar grasp reﬂex was examined before 1 year of age [5]. Their diagnoses were conﬁrmed by follow-up examinations and comprised normality in 458, CP in 78, and mental retardation (MR) in 81. We obtained several results: the reﬂex reactivity in infants with CP of the spastic type was signiﬁcantly reduced; infants with CP of the athetoid type exhibited an extremely strong retention of the reﬂex; infants with MR also exhibited a tendency for prolonged retention of the reﬂex; the reﬂex proﬁle in infants with CP of the athetoid type with spasticity, or of the ataxic type, was not diﬀerent from that in normal control subjects. Other authors also reported the characteristics of the plantar grasp reﬂex in children with neurodevelopmental abnormalities of various types, and their results were well consistent with ours [26, 27, 34]. A reduced or negative plantar grasp reﬂex during early infancy can be a sensitive indicator of later development of spasticity. Of 2267 infants whose plantar grasp reﬂex had been examined before 1 year of age, we analyzed the neu- rodevelopmental outcome in 47 infants exhibiting a negative response during the ﬁrst 6 months of age and in 46 infants exhibiting a signiﬁcantly reduced response at ages 1 to 4 months [6]. The diagnoses comprised CP in 75, MR in 7, borderline intelligence in 2, motor delay in 1, and normality in 8. Of the 75 cases with CP, 69 had the spastic type and 4 the athetoid type with spasticity. The total number of patients with CP of the spastic type or the mixed type with spasticity among the entire 2267 infants in this series was 107, and 73 of these 107 patients with CP with spasticity (68.2%) exhibited a negative or reduced response during early infancy. In the remaining 34 infants with CP with spasticity who exhibited a normal response during the corresponding period, the extent of motor disturbance was signiﬁcantly milder [35]. A high concordance between the side of an abnormal plantar grasp reﬂex during infancy and the laterality of the disturbance of motor function in children with CP of the spastic type was demonstrated [36]. The side aﬀected, or more aﬀected, in motor function was in accordance with the side that exhibited a diminished or more diminished response in most subjects with spastic hemiplegia, diplegia, and quadriplegia.