The characteristics of foot soft tissues in pre weight-bearing
infants

Martinez Santos, A; Price, C; Morrison, S; Nester, CJ; Hashmi, F

Abstract

Background: Foot skin and soft tissue characteristics such as hydration, pH, elasticity or thickness will vary in response to the loads the
foot will bare when the infant starts walking. Previous studies have
concluded that infant skin is more hydrated (Stamatas et al., 2011),
less elastic (Visscher et al., 2017) and its pH decreases immediately
after birth (Fluhr et al., 2010) compared to children and adult skin.
These studies also showed that skin characteristics have a high anatomical and inter-subject variability. The anatomical regions where
skin characteristics have been previously measured include buttocks,
chest or arms. However, there are no studies describing the characteristics of the soft tissue of infantfeet and how these change after
weight-bearing, despite the significant change in demand on these
tissues during this stage in life.
Aim: To quantify the characteristics of the soft tissues of infant feet
before they start regularly weight-bearing.
Methods: Twenty-two babies (21.6 ± 3.6 weeks old, 9 female were recruited as part of an ongoing study (Price et al., 2018)). They had
been reaching for their feet while laying on their back for up to 2
weeks (16.7 days average). Skin thickness, pH, elasticity and hydration data were collected using DermaLab Combo (Cortex Technology,
Denmark) on up to 5 foot regions (heel, medial midfoot, lateral midfoot, forefoot, and dorsum). Achilles tendon thickness was also quantified using Venue 40 Ultrasound (GE Healthcare, UK).
Results: The hydration of the skin is 20% higher on the heel and the
1st metatarsal head, but the results have a high inter-subject variability (up to 70 arb. Units per site). Regarding pH, the plantar aspect
showed a stable value of 5.2 ± 0.3, slightly lower than the dorsum
5.4 ± 0.3. Skin thickness results show that the areas that will receive load in mature walking (heel, lateral midfoot and forefoot) are
thicker (over 1000 μm) than the dorsum or the medial midfoot
(below 1000 μm). Finally, the Achilles tendon has an average thickness of 2.61 ± 0.38 mm. Once the whole data set is collected statistical tests will be performed in order to investigate the differences in
the skin characteristics between the areas that will be loaded and
those that will not. Comparison will also be made to a following longitudinal data set, which measures the skin again during and after
the onset of walking.
Conclusions: The characteristics from areas that will be loaded during
gait (heel, lateral midfoot and forefoot) seem to be different to those
that will receive less load (dorsum and medial midfoot) even before infants are regularly weight-bearing. In line with previous studies, foot
skin characteristics are highly variable across participants.

• Presentation Conference Type: Conference Paper (published)
• Conference Name: College of Podiatry Annual Conference 2018
• End Date: Nov 24, 2018
• Publication Date: Dec 9, 2019
• Deposit Date: Feb 17, 2022
• Publicly Available Date: Feb 17, 2022
• Journal: Journal of Foot and Ankle Research
• Electronic ISSN: 1757-1146
• Publisher: Springer Verlag
• Volume: 12
• Issue: Sup. 2
• Pages: 54
• DOI: https://doi.org/10.1186/s13047-019-0364-8
• Publisher URL: https://doi.org/10.1186/s13047-019-0364-8
• Related Public URLs: https://jfootankleres.biomedcentral.com/
• Additional Information: Event Type : Conference