Gait Development in the Growing Child

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Original Editor - Kapil Narale

Top Contributors - Kapil Narale, Lauren Heydenrych, Naomi O'Reilly, Kim Jackson and Rishika Babburu  

Introduction

Gait is defined as "upright locomotion in a particular manner of moving on foot which may be a walk, jog or run".

A narrative review done by Wei Liu et al. (2022) further described gait as "... a movement pattern of limbs, especially lower limbs on a substrate, which can fulfill the primary need of locomotion and provide propulsion and support for the body." This definition itself was taken from 'Gait Analysis' written by M.W. Wittle (1991).

When does gait development start?

The first observed gait-type behavior can be seen is at birth, with the flexion-extension of the legs when an infant is held over a support surface and moved slowly across the support surface. With this observed, recent studies demonstrate that only 70-84% of healthy infants will demonstrate step-like patterns and only 25% will use a left-right patterning of stepping. More observable than a stereotypical stepping pattern is a variety of limb movements which are noted to be reproductions of limb movements in the womb.

The initiation of independent gait is generally considered to be around 12 months of age. However, Wei Liu's review cited that up to 10% of children at 12 months had difficulty with this milestone at 12 months. Furthermore, in a study done by the WHO (World Health Organization) in 2006 independent ambulation (without support) occurred across a spectrum of 8 to 18 months.

Gait at Different Ages

At birth reflex stepping is observed, as described above. This persists until 2-3 months of age, disappears and then re-emerges close to the onset of autonomous walking.

Early autonomous gait

With the start of autonomous walking, there is flat-footed stepping, with the emergence of heel strike around 18 months. There is no arm swing, rather upper limbs are kept in a 'high guard' position. Persistent knee flexion, along with hip abduction and external rotation is also observed. There is also short steps, a rapid cadence and generally a large degree of pelvic rotation.

In a study performed by McCollum et al. (1994) 3 basic walking forms were identified:

1. The Twister - Who winds up the trunk like a spring and then swings a leg around using the torque and angular momentum of the trunk. In this form the feet stay about the same width apart. Balance is easily maintained with no forward momentum generated and feet kept wide apart.
2. The Faller - Who exchanges gravitational potential energy for kinetic. This child moves forward onto tiptoe for a moment, with the fall forward allowing the swing leg to be brought forward to break the fall and downward momentum being converted to forward momentum. The Faller is brought back to the original stance leg by a quick step close to the ground. Balance is precarious and the Faller is unable to stop.
3. The Stepper - Uses conservation/balance strategy. This child uses very small excursions of teh feet,i.e short steps are made from a stable, balanced double stance. Balance is solid due to the double stance phase.

By the age of 2, a child will demonstrate heel strike and reciprocal arm swing. Along with less hip abduction and external rotation.

Children at the age of 3 years are seen to have a mature gait. Any unsteadiness that can be visually observed develops into a stable gait pattern. However, this does not mean that the gait has been fully matured. Gradual and progressive development in neuromuscular control and locomotor function continue beyond this age. There may be decreased variability in gait after this age.

Children between 7 and 8 years old are able to achieve independent control of each anatomical segment with walking, thus maintain a stable posture during gait compared to children between 3 and 6 years old. The reduction in gait speed variability as children age could be due to improvements in balance control and posture. It is seen that gait development increases until the age of 8.

It should be noted that different features of stride dynamics develop at different times, hence no two features develop to the same time. There are differences between children of the same age.

Influences in gait development

In recent research, it has been recognized that gait development not only occurs across a varied time span but also with varied observable development. Factors that influence gait development include:

• Age
• Walking experience
• Body dimensions/ biomechanical development
• Neurological: Maturation of the central nervous system
• Muscle-fat ratio
• Development of the musculoskeletal system
• Head-trunk postural stability
• Environmental factors

Gait development is also seen to change with development of different body systems, such as musculoskeletal (strength and range) and sensory (response to tactile input and proprioceptive input of compressed joints in the gait cycle)

The development of gait incorporates components such as maximizing step frequency (cadence), gait symmetry, balance control, and stability of the gait cycle. The function of these components are facilitated with structural development and neural control of movement.

The development of gait is categorized into six stages: infant stepping, inactive period, supported locomotion, unsupported locomotion, mature similar gait, and mature gait.

During the maturation stage, gait speeds increase to mature values. Despite factors influencing gait and gait speed, such as growth and neuromaturation, that are not fully developed, mature gait is said to be reached at the ages of 5-7 years. Until the end of puberty, changes in body structure and sensory motor development occur.

It is seen that healthy infants generally display organization of thoughts and discovery of new movement patterns, including walking. It is believed that some of these patterns are programmed into the genetic code.

Development and Plasticity

It is interesting to note that a neonate's stepping reflex shows variability in patterns as well as frequency when compared from one individual to another. In addition, step frequency and variability are also influenced by environment and level of arousal. These observations highlight fact that stepping in the newborn is not preset or ingrained, rather it develops with time and repetition of practice. Thus demonstrating the adaptability of the neural system and a level of neural plasticity.

From a neuromuscular aspect of development, the variability in muscle activations observed during early stepping is the same seen in other developmental tasks. Once again showing a multi-system (neural, muscular and sensory) which is plastic and adaptable.

In an longitudinal study performed by Thelen (1986a) babies were put onto a baby treadmill at varying ages. Throughout their development they demonstrated adaptive gait reactions to speed of the treadmill as well as direction - babies being able to learn to walk backwards.

Components of gait development

Stepping could be a phenomenon that can contribute to walking, and the action of walking itself is a skill to be learned.

This movement most likely occurs through a combination of active neural input, and passive dynamics, biomechanics of lower limb rotation with the effect of gravity.

Overall, it is seen that meaningful and progressively difficult practice of stepping have a long-term effect on functional neuromotor pathways.

Gait Speed

Gait speed is commonly used to assess gait development. It is one of the basic characteristics used to assess and analyze gait parameters. There is high variability when comparing different steps taken in children. Age and body height are two factors which contribute to varying walking speed.

An individual's gait speed has an influence on their kinematics and kinetics during gait. Thus, from a study by Stansfied et al, 2001, it was shown that walking speed, not age, has the primary influence on gait kinematics and kinetics in growing children. Speed has a similar effect on muscle activity. At very slow speeds, although muscle activity wouldn't bee expected, there is gradual activation noticed in muscle activity due to the increased stability demands.

It is seen that gait speed gradually increases with age and height, up to the age of 15 years, thus it follows that age and body height are some of the determinant factors for walking speed variability. Younger children do have a lower gait speed, while older children have a higher gait speed.

It is seen that walking speed can increase up to the age of 8 years, whereas an enhanced walking speed develops up to the age of 15. However, regardless of age, body height changes display a more uniform increase in walking speed, showing that waling speed is dependent on segment (leg) length and body height.

Children at 1 year of age had the slowest walking speed. It is seen that walking speed increases every year as children age, until the age of 15 years. Standard deviations for 1 and 2 year old age groups were the highest, and were the lowest for the 15 years age group.

The youngest and smallest children displayed the highest variability. The respective phase of motor control learning has a high error rate, a weak reproducibility, and reduced stability. In toddlers, there would be higher variability due to the lack of postural control, efficient integration of afferent information, and supraspinal control.

Stride to Stride Variation

Successive stride-to-stride changes represents the time between one stride and the previous stride. The degree of stride-to-stride variability decreases as healthy children mature.

Stride-to-stride variability is largest in the 4-year old group, a little smaller in the 7-year old group, and the smallest in the 11-year old group. It is seen that there is a highly significant effect of age on variability. The SD (standard deviation) and CV (coefficient of variation) was higher in the 3-4 age group, than the 6-7 age group, and this was higher than the 11-14 age group. The stride-to-stride variability in the 11-14 years age group was similar to that found in healthy young adults. Through observation, even though it may appear that the stride dynamics of children are similar to those of adults, quantitatively it is seen that stride-to-stride control of gait dynamics is not fully matured by the age of 7.

Analyzing stride time dynamics in children may provide insight into the development of neuromuscular control. Stride time dynamics would not be fully matured by the age of 3. The variability of stride time dynamics in younger children can be caused by many factors. It can be caused by a decreased walking speed, and thus decreased postural stability at the lower speeds.

Stride Dynamics and Height

It is seen that after a certain age range, stride length increases linearly with age. However, the relationship between stride length and age becomes constant subsequent to accounting for height or leg length.

It is seen that there is a significant increase in walking speed in the 6-7 year old age group, compared to the 3-4 year old age group. However, relative velocity (velocity/height) was identical in these age groups.

The studies also showed that the average values of stride time and walking velocity were age dependent. These average values were lowest in the 3-4 age group, moderate in the 6-7 age group, and highest in the 11-14 age group.

In addition, it is seen that the temporal structure of gait variability is not fully developed in 7-year old children, whereas in the 11-14 year old age group the stride dynamics are similar to those found in healthy adults.

Implications for physiotherapy

• Early intervention: With gait being an aspect of motor control being developed as early as in-utero, early intervention for those infants with known neuromotor disabilities should be taken as early as possible. Active intervention should not be withheld until gait is attempted/ initiated by the infant.
• Movement is 1. Goal directed and 2. Influenced by the individual and environment: Self-organization and discovery of new movement patterns are goal driven and are directed by an individuals ability and their environment. These should always be held in regard when facilitating patterns of movement and skill acquisition.
• Skill acquisition requires practice and repetition.
• Motor learning involves multiple systems: When considering motor sensory training, it is important to bring in aspects of tactile, proprioception and even vision stimulation.
• Partial body-weight treadmill training may be used as a therapeutic intervention. Evidence suggests it acts on the sensory, motor, neural ad musculoskeletal systems.

Resources

Here are two related pages concerning gait and pediatrics:

• Gait Analysis in Cerebral Palsy
• Gait and Lower Limb Observation of the Lower Limb of Paediatrics - (GALLOP)

Here are some videos for a visual, and to better explain gait development in the child:

This is a presentation on the walking gait development through the four stages of life: Early Childhood, Childhood, Adulthood, and Older Adulthood.