Introduction
The inhibition or integration of primary reflexes, understood as the
suppression of one function through the development of another (Goddard,
2005), together with the emergence of postural reflexes, which allow for
functional and voluntary motor responses (Medina et al., 2015), plays a
fundamental role in child development (Damasceno, Delicio & Mazo,
2005). This transition from primary to postural reflex is important as
it connects basic postural and motor skills in the early years with the
development of later motor skills (Goddard, 2005). In addition, it seems
that active primary reflexes may make a child’s posture and motor skills
look clumsy (Gieysztor, Pecuch, Kowal, Borowicz & Paprocka-Borowicz,
2020).
The most severe consequences of primary reflexes persistence are
typically found in children with cerebral palsy, while milder
persistence has been observed in children with reading difficulties and
motor problems (McPhillips, Hepper & Mulhern, 2000). It has also been
shown that the non-integration of primitive reflexes can cause
developmental delays, and is associated with a variety of disorders,
such as ADHD (Konicarova, Bob & Raboch, 2013), autism, learning
difficulties (Bilbilaj, Gjipali & Shkurti, 2017; Hickey & Feldhacker,
2021; Matuszkiewicz & Gałkowski, 2021), dyspraxia (Pecuch et al.,
2020), dyslexia, behavioral disorders (Rashikj-Canevska & Mihajlovska,
2019) or sensory processing disorders (Bilbilaj et al., 2017, Pecuch et
al., 2020, Rashikj-Canevska & Mihajlovska, 2019).
If primary reflexes inhibition does not occur in a proper and orderly
manner, children may develop, in addition to other difficulties, poor
Motor Competence (MC) (Gieysztor, Choińska & Paprocka-Borowicz, 2018).
Early signs of this may appear as difficulties in running, balance,
aiming and catching tasks, poor visual coordination, lack of rhythm or
defective spatial orientation (Gieysztor et al., 2018; Pecuch,
Kołcz-Trzęsicka, Żurowska & Paprocka-Borowicz, 2018; Pecuch et al.,
2020).
The primary reflexes considered in this research are those that are most
directly related to the acquisition of coordination, balance and
physical-sport skills: the Moro reflex (MR), the tonic labyrinthine
reflex (TLR), the asymmetrical tonic neck reflex (ATNR) and the
symmetrical tonic neck reflex (STNR).
Failure to inhibit the MR can cause difficulties in balance and
coordination, which will become evident during ball games (Goodard,
2014). Furthermore, it can lead to excessive muscle tension (Bennet,
1988, cited in Goodard, 2015) which, if prolonged, would lead to fatigue
(Goodard, 2015) and, consequently, poor task performance. Instead,
non-inhibition of the TLR can lead to poor posture, weak muscle tone and
low competence in activities involving temporal sequences (Kokot, 2006).
In the case of the ATNR, its non-inhibition may influence motor patterns
involving the trunk and limbs, which attempt to align with the head
(Henderson et al., 1993). This results in homo-lateral movements,
instead of the cross-lateral pattern that should occur when walking,
running or jumping (Goodard, 2015), which negatively contribute to the
development of the crawling cross-lateral pattern (Krog, 2015).
Finally, if the STNR remains active, as with the MR, it may increase
children’s difficulties in properly throwing or catching a moving object
(Goodard, 2005). Furthermore, this reflex acts as a developmental bridge
to the locomotion stage, when children begin to crawl on their hands and
knees (Krog, 2015). Although it allows the child to adopt the
quadrupedal position, it will prevent progress in this position if it is
not properly integrated (Goodard, 2015).
The crawling pattern, another variable considered, favors the
integration of the right and left sides of the body, the acquisition of
adequate spatial awareness and the development of hand-eye coordination
(Hannaford, 2005). Besides, it contributes to the development of motor
skills associated with other developmental areas, such as social
cognition and language (Leonard & Hill, 2014). It is also important for
a child’s overall development, and physical, psychological and general
well-being (Barnett et al., 2016), although most authors agree that it
is not a necessary milestone (Oldak-Kovalsky & Oldak-Skvirsky, 2015).
There is broad evidence that primary reflex activity can exist in the
general population (Demiy et al., 2020; Gieysztor, Sadowska & Choińska,
2017; Gieysztor et al., 2018; Gieysztor et al., 2020; Grigg,
Fox-Turnbull & Culpan, 2018; Hickey & Feldhacker, 2021; Matuszkiewicz,
& Gałkowski,2021; Pecuch et al., 2020; Rashikj-Canevska & Mihajlovska,
2019). Plentiful research has been conducted in children with several
difficulties (Bilbilaj et al., 2017; Chinello, Gangi &Valenza, 2018;
Konicarova et al., 2013; Mc Phillips & Jordan-Black, 2007; Pecuch et
al., 2018, Taylor, Houghton & Chapman, 2004). However, there are few
studies assessing the lack of inhibition of these reflexes and their
relationship with MC in early childhood (Gieysztor et al., 2018; Pecuch
et al., 2018), despite it being a developmental stage in which the first
signs of poor reflex inhibition become apparent (Gieysztor et al.,
2018).
For these reasons, the aims of the study were to analyze the
relationships among the level of inhibition of primary reflexes, MC and
the development of the crawling pattern in children, and to assess these
relationships according to the participants’ gender. These aims were
specified in four hypotheses: (1) the non-inhibition of primary reflexes
will be higher in those children who show lower MC, (2) the
non-inhibition of reflexes will be lower in those children who have
developed the crawling pattern, (3) having developed the crawling
pattern will be associated with higher MC and, finally, (4) the
non-inhibition of primary reflexes will be higher in male participants.