From “first” to “last” steps in life – Pressure patterns of three generations

Abstract

Background

The human foot has to bear loads during all kinds of bipedal locomotion throughout the whole life. Rapid developmental changes of foot morphology and foot function occur during the first years of walking. Furthermore, disease dependent modifications can also have an influence on plantar loading. Therefore, it is reasonable to assume that foot function will undergo changes in life. However, the main differences between the pressure patterns in young and elderly have not been well described. The aim of the study was to evaluate age-dependent pressure patterns in different age-related stages.

Methods

Hundred and four healthy humans of four different age groups were retrospectively analysed by means of plantar pressure measurements (toddlers: mean age 1.0 (SD 0.2) year; 7-year olds: 7.0 (SD 0.4) years; adults: 31.9 (SD 2.1) years; seniors: 68.7 (SD 3.2) years). The emed^® pressure platform was used to evaluate peak pressure, maximum force, contact time, contact area and arch index.

Findings

Significant differences were found for each parameter between almost every age group. The highest peak pressure values were observed for the seniors’ (P < 0.001). Peak pressures are low in toddlers (145 kPa), high in 7-year olds and adults (400–600 kPa) and even higher in elderly (⩾800 kPa).

Interpretation

Elderly adults can still be functionally mobile even if pressures are high. The results for the investigated age groups can be used as normative foot loading data to compare to pathological foot function.

Introduction

The first steps in life are a special event in the development of humans, since learning to walk is fundamental to the acquisition of independence and autonomy. The foot is the only connection to the ground during bipedal locomotion, it has a vital function in load bearing and has to adapt to structural and functional changes which occur throughout life.

The infant’s foot is predominately cartilaginous, the shape is flat, fat and soft with the presence of Spitzy’s fat pad (Spitzy, 1903). Because of these attributes, the growing foot is sensitive to impacting forces caused by crawling, upright posture and the first steps. Consequently, structural and functional changes of the foot develop rapidly during the first years of walking. For instance the occurrence of the initial heel strike, the maturation of the longitudinal arch and the increase of peak pressure (Bosch et al., 2007, Bertsch et al., 2004, Hallemans et al., 2006, Staheli, 1998). Furthermore, the midfoot plantar fat pad shifts to the hindfoot and forefoot region during the first years of growth (Fritsch and Schmidt, 1993). Therefore, its primary function of shock absorption under the midfoot diminishes with age.

Apart from aging, disease dependent pathomechanisms of the foot, e.g. caused by neuropathy and rheumatoid arthritis, can also influence foot loading (Bus et al., 2004, Giacomozzi et al., 2002, Schmiegel et al., 2008). Foot function changes because of growth, aging and disease dependent degenerative processes during life. The literature provides some knowledge about healthy infants’ foot loading during the first years of independent walking which is characterized by low peak pressures, high midfoot contact area and a low arch height (Bertsch et al., 2004, Bosch et al., 2007, Hallemans et al., 2003). Additionally Hennig and colleagues reported three times higher relative midfoot load in infants in comparison to young adults but generally reduced peak pressures underneath the foot (Hennig and Rosenbaum, 1991, Hennig et al., 1994). Furthermore, studies about foot loading in elderly compared with young adults showed a decrease of peak pressure and force under the hindfoot and forefoot and longer contact times for the midfoot area (Hessert et al., 2005, Kernozek and LaMott, 1995, Scott et al., 2007).

However, none of these investigations have considered more than two age groups. It is not clear yet, whether there are age specific pressure patterns. It is known that foot function changes during life (Bosch et al., 2007) and it is expected that different pressure patterns represent characteristic foot function for specific periods of life. A report of plantar pressure patterns of different generations during natural walking would provide the clinician with the bandwidth of foot function and help to distinguish the physiological/normal roll over process from pathological foot function.

Therefore, the aim of the present investigation was to compare four different healthy age groups of three generations, and compare a group with almost no walking experience to a group with up to 69 years of walking history, as well as school aged children and young adults to demonstrate age-dependent foot function during natural walking.