NRS Week 6 Notes – Fundamental Motor Skills and Gait in Different Populations
Overview
Topic: fundamental motor skills in early childhood, focusing on lower-limb mobility between roughly and ; some upper-limb skills are touched on.
Core skills covered: early locomotion, jumping, hopping, throwing, catching, with emphasis on how these skills emerge, mature, and progress in order.
Main ideas:- Proficiency in fundamental motor skills is linked to higher physical activity, fitness, and potentially better academic performance.
Environment and opportunities (e.g., school, play, sports) influence how efficiently children learn and mature these skills.
Clinicians assess milestone achievement to identify delays and guide interventions.
Practical framing: use of age bands to illustrate typical onset and maturation, plus descriptions of how mature patterns differ from early-stage patterns.
Objectives
Describe the fundamental motor skills (early locomotion, jumping, hopping, throwing, catching).
Describe how these skills emerge in young children versus mature learners.
Describe characteristics of skills from least mature to most mature; outline the relative order of skill emergence by age.
Understand the influence of environment on fundamental motor skill development.
Recognise that adequate opportunities (e.g., schoolyard, play, sports) support achievement of mature motor patterns by age .
Note potential concerns when milestones are delayed and how assessments inform referrals.
Link proficiency with higher physical activity, fitness, and broader cognitive/academic implications (e.g., engagement in class, motivation).
Development window and environment
Development window: roughly from about (and possibly a bit earlier) through , with a notable five-to-six-year period for progression.
With adequate opportunities (play, school-based activities, sports), many children reach mature motor characteristics by age .
Environment matters: opportunities to practise and refine skills in varied settings influence learning rate and quality.
Practical implication: in clinical or school settings, monitor for delays and provide enriched, supportive environments to promote skill maturation.
Locomotor skills: walking, running, jumping, hopping, galloping, skipping
Walking and running
Walking: typically established around ; variability exists (earlier or later possible).
Running: begins after walking; a key transition occurs around (early stages may resemble a trotting gait).
Walking vs running pattern features:- Early walking/run development shows a balance of stance and swing phases; early running introduces more flight (non-support) phases.
Early running can be described as a “high guard” arm posture for balance, reflecting limited reciprocal arm swing.
Transition to mature running:- In early running, children may land more on the heel with a flat-foot pattern and limited trunk rotation.
As stride length increases (due to growth and strength), propulsion from the plantarflexors (e.g., gastrocnemius, soleus) increases, contributing to a longer flight phase.
Mature running features include: trunk rotation, reciprocal arm swing, landing with more varied foot strike, and improved propulsion.
Age progression for running patterns:- First true run: around .
Efficient and refined run develops with age; pattern becomes more mature with longer stride length and faster speed.
Practical note: when asked to perform a maximal jump or run, children often show a progression from high guard to more dynamic trunk and arm involvement as they mature.
Jumping (distance, height, from height)
Forms of jumping include:- Jumping for distance
Jumping for height
Jumping from a height (and landing)
Takeoff and landing patterns:- Common pattern: one or two feet takeoff, landing on two feet (ground reaction forces distributed to legs).
Early-stage jumping (developmental sequence):- Early landing and takeoff show a shallow, non-optimized preparatory crouch;
Head and trunk flexion are prominent; arms are held high (balance/guard mechanism).
Mature jumping pattern: contains preparatory crouch, arm propulsion overhead, trunk involvement, and coordinated takeoff/landing.
Age milestones for jumping:- Very early: – jump down from low objects (one foot leading).
– jump down from an object with a lead foot.
– jump off the floor with both feet (vertical or forward jump).
– jump for distance (about ) and jump for height (about ); preparatory crouch and arm swing contribute to momentum.
By – mature jumping patterns are more evident; height/distance improve with practise.
Commentary: adult-like jumping (with effective crouch, arm drive, and trunk involvement) becomes more common as children age into early school years.
Hopping
Definition: hopping involves takeoff on one foot and landing on the same foot.
Distinction: hopping is not the same as galloping (which is asymmetric and involves a leading and trailing leg).
Early-stage hopping: arms are held high to aid balance; limited flight phase.
Later development: reciprocal arm swing with swing leg; improved hip/knee extension and coordination across hip, knee, and ankle.
Age progression and counts:- : about hops on the same foot.
: about hops on the same foot.
: about hops on the same foot.
Distance benchmarks: hopping distance around in about at the later stage.
Mature hop pattern: skillful and rhythmic hopping with coordinated arm movement and trunk control.
Galloping
Definition: an asymmetric gait with leading and trailing legs, often described as a rhythmical step-like motion.
Pattern characteristics:- Leading foot followed by trailing leg.
About a 65 ext{ %} swing phase and 35 ext{ %} stance phase in the mature pattern.
Early stages show arms held high, minimal propulsion, short strides, flat feet, and limited trunk rotation.
Mature gallop features longer, more rhythmic strides, enhanced trunk rotation, and reciprocal arm movements aiding propulsion.
Age progression:- : basic but inefficient gallop.
: gallop becomes more skilled with a mature pattern.
Environmental influence: practise opportunities influence how quickly children adopt a mature gallop.
Skipping
Definition: alternating gait pattern involving a step and a hop on one leg followed by a step and hop on the other leg.
Progression:- Early stage: one foot completes the step and the hop before the other; arms are held high; feet are flat.
Mature stage: weight transfer becomes smoother; reciprocal arm movement improves joint rotation and momentum; weight transferred through the ball of the foot rather than the heel.
Age milestones:- : can perform one-foot skipper.
: around 20 ext{ %} of children perform a skillful skipper.
By : most children can perform a skillful skipper, depending on encouragement and opportunities.
Object control skills (ball-related)
Kicking
Goals: impart force on a ball using the foot.
Early stage (approx. ): trunk largely still; short forward swing from a neutral hip; arms act as balance; minimal hip extension.
Mature stage: reciprocal arm swing with the kick leg; hip extension to preload and load hip flexors; trunk flexors during follow-through; rise onto the toes of the non-kicking leg to augment force.
Age progression:- Straight-leg kick with one and a half to : strong lever arm and straightforward kicking action.
: knee flexion in preparatory swing; increased force development.
: hip extension, trunk rotation, reciprocal arm swing; more mature momentum.
Throwing
Definition: imparting a force to an object in the intended direction.
Early stage: arm moves up and sideways with elbow flexion; trunk flexes during forward motion; the throwing leg steps forward.
Mature stage: arm loaded in abduction and extension; trunk rotation contributes to propulsion; opposite arm helps counterbalance; trunk and pelvis rotate to aid force production.
Age milestones:- : body faces target; feet stationary; forearm extension only; ball thrown primarily with forearm.
: step forward with one leg; more mature pattern emerges; boys may show more mature throwing earlier than girls (likely due to experience and practise).
: boys often more mature than girls at this stage (note: individual variation exists).
: body rotation added; throwing pattern more mature; some sources cite as a mature throwing pattern.
Catching
Early stage: arms extended in front; limited body movement; tracking may be limited; catching often driven by chance (ball lands in forearms or hands depending on thrower).
Mature stage: eyes track the ball; arms and hands adjust to ball flight; fingers and hands grasp the ball; ball caught more in hands rather than forearms when tracking is good.
Age progression:- : chase the ball; response to aerial ball is limited; delayed arm movement.
: some response to aerial ball; still needs guidance to position arms.
: basket catching using body; improved tracking and catching mechanics.
: more complex catches (catch and clap, combinations, etc.).
Age-by-age milestones (grouped by age bands)
- Walking well; starting to run around the mark.
Stops/starts safely.
Pushes/pulls large wheeled toys (around ).
Crawls upstairs and backwards downstairs.
Walks upstairs with a handheld support; squats to pick up toys and stands back up.
Backs or slides sideways into a small chair; seats self and can turn around at a table.
- Runs well; stops/starts safely.
Walks upstairs with a rail; two feet per step.
Climbs on furniture; explores play environments.
Sits on a tricycle (or balance bike) and propels with feet to move.
- Jumping down from a step (often a couch or similar low object).
Climbs easily on playground equipment.
- Walks upstairs with alternating feet.
Walks on tiptoes; stands on one foot for 3–5 seconds.
Climbs playground equipment capably; rides/tricycles; turns by a quarter; runs forward and backwards.
- Hops 1–2 times on preferred foot.
- Walks heel-to-toe along a line with two or fewer steps off; line walking as a motor control assessment.
Walks easily up and down stairs with alternating feet; runs on tiptoes; climbs ladders and high playground equipment.
Rides a tricycle more quickly; begins turning sharp corners.
Stands on either foot for 4–8 seconds.
- Jumps over in height.
Hops on each foot at least times.
Performs more complex transitions (walks along chalk lines, climbs safely).
- Stands on one foot for seconds with arms folded; skips or pops on one foot.
Rides a bicycle-like setup with more skill and control; performs more stunts in play.
- Runs well; turns quickly on the spot; stands on one leg for up to with hands on hips.
Jumps over height; hops on either leg in a coordinated skipping pattern.
Assessments, implications, and practical notes
Milestone monitoring:- Clinicians track whether a child hits typical milestones for age and provide referrals if delays are observed.
Why this matters:- Proficient motor skills correlate with higher levels of physical activity and fitness, which in turn relate to broader health outcomes.
There are links between motor skill proficiency and academic performance/cognitive function, possibly due to increased participation, confidence, and engagement in school settings.
Practical assessment cues:- Observing stance, arm swing, trunk rotation, and foot strike can indicate maturation of running and jumping patterns.
Use simple, age-appropriate tasks (line walking, hopping on a single foot, catching and throwing with small balls) to gauge progression.
Real-world relevance:- Early physical education, playground opportunities, and sport participation promote motor skill development.
Encouraging environments help children progress toward mature, efficient movement patterns by age 7.
Gender differences at certain ages (e.g., boys vs. girls in kicking/throwing spurts) can reflect experiential differences; individual variation is substantial.
Connections to broader principles
Developmental principle: motor skill maturation progresses with practise and biological growth (strength, coordination, balance).
Environmental principle: availability of age-appropriate opportunities accelerates or limits skill development.
Interdisciplinary connections: motor proficiency supports physical activity, fitness, and may influence cognitive/academic engagement.
Practical implications for parents and clinicians: provide safe, varied opportunities to explore walking, running, jumping, hopping, galloping, skipping, and ball skills; tailor activities to the child’s current stage and gradually increase complexity.
Mathematical notes and reference figures from the lecture
Gait patterns and phase proportions:- Early running: stance vs. swing roughly equal; flight phase begins to appear as maturity increases; approximate guidance:
Mature gallop: swing phase around 65 ext{ %} and stance phase around 35 ext{ %}.
Jumping distances/heights (typical targets):- Height: (approximately) for some 4–5 year-olds.
Distance: about for distance jumps in the same age range.
Hopping benchmarks: at age 5–6, hops should be on the order of repetitions on one foot; total hop distances can reach around in roughly
LECTURE 2 – Gait Differences
Objectives
Describe age-related changes in mobility and how walking changes across the lifespan, focusing on older adults.
Describe age-related changes in kinematics (joint angles), kinetics (forces/motors), and electromyography (muscle activation) during gait in older adults.
Describe age-related changes in sensory-motor and higher cognitive processes that relate to gait.
Describe age-related changes associated with other forms of mobility, including stair climbing and walking backwards, and how aging influences these tasks.
Reminder: mobility and gait as a foundation for independence
Mobility/gait is critical for independence and quality of life; even small mobility gains can maintain home living and daily function.
After injury or surgery (e.g., stroke), early mobility goals often focus on standing up, transferring to a wheelchair or toilet, and taking a few steps, which supports preserving upper-limb function and overall independence at home.
Gait is a highly automated, complex motor skill achieved via cyclic activation of left and right limbs with synergistic muscle activity to produce an efficient pattern.
Key components of mobility in daily life include progression, which involves moving the body forward in the intended direction.
Initiation and termination: starting and stopping movement (e.g., waiting at a crosswalk).
Stability: maintaining posture and controlling the centre of mass within the base of support.
Adaptation: adjusting gait to meet environmental demands (e.g., stepping onto a curb, avoiding a car running a red light).
Throughout a walk, the base of support (BoS) changes: during swing, BoS is basically the stance foot; during double-support, BoS is the region between both feet. The centre of mass must be kept within BoS to stay upright.
Environmental demands require gait adaptation (e.g., uneven surfaces, curbs, traffic).
Why focus on older adults?
Falls are a major issue and a leading cause of injury-related death in adults >65.
Mortality related to hip fracture after falls is high:
With surgical repair, 12-month mortality ~ 21%.
With conservative (non-surgical) management, 12-month mortality ~ 70%.
These mortality risks are linked to inactivity during recovery, decreased weight-bearing, cardiovascular deconditioning, and muscle wasting.
Older adults often avoid risky environments to prevent further decline, which can itself contribute to reduced mobility and health risk.
Aging involves both primary and secondary changes:
Primary aging: intrinsic biological changes (gene expression shifts, telomere shortening, hormonal changes) that influence gait.
Secondary aging: environmental and lifestyle factors (nutrition, exercise, stress, comorbidities such as diabetes, peripheral vascular disease, stroke) that can modulate gait and mobility trajectories.
Clinically, it is important to differentiate primary aging processes from secondary, potentially modifiable factors when planning interventions.
Spatial-temporal characteristics of gait in aging
Aging is associated with slower walking speed, shorter step length, reduced cadence, and longer double-support time.
These four features are interrelated: slowing speed often coincides with shorter steps and lower cadence, which increases the time both feet are in contact with the ground.
Sex differences: The effects on spatial-temporal measures may be more pronounced in females, potentially linked to hormonal changes (e.g., menopause) and differences in muscle properties/size with aging.
Comfort strategies to improve stability include: Increased step width (base of support) to enhance stability.
Greater toe-out angle to widen BoS and improve stability.
Kinematics of gait in aging
Head and trunk: the head becomes a less mobile, more rigid segment; movements in vertical and lateral directions decrease as people try to keep the centre of mass within BoS (a more “stable” profile).
Lower limb joint angles: reduced hip, knee, and ankle flexion observed in older adults; this reduces foot clearance during swing and can increase tripping risk.
Ankle mechanics: reduced dorsiflexion during late stance; smaller plantarflexion push-off reduces propulsion.
Foot strike: reduced heel strike with diminished ankle dorsiflexion at terminal stance; overall swing-phase clearance can be compromised.
Upper body posture: less shoulder flexion, often a more extended posture; weight distribution tends to be placed more on the heel during ground contact (posteriorly biased CoM) which may be a protective strategy in those with fall risk histories.
Older adults without a history of falls often walk with patterns similar to younger adults; gait changes are more pronounced in those with a falls history.
Gait variability and measurement in aging
Gait variability reflects the ability to adapt to environmental demands; some variability is normal for adapting to surface changes, obstacles, and tasks.
In clinical vs. unstable environments, gait should be relatively consistent on flat, controlled surfaces; high variability in step-to-step measures can indicate instability or increased fall risk.
Measurement approach (example from GateRite video):
Step length can be extracted as the distance between consecutive heel strikes of the same foot or opposite feet, across a walk trial.
Variability is quantified as the standard deviation (SD) of step length across steps:
Example: step length left/right and SD values are generated, and higher SD indicates greater variability.
Research findings: higher gait variability in older adults correlates with increased past falls or higher fall risk; in some data, impairment in variability is used to identify individuals at risk.
A reference point: a normative database is available for comparison; deviations beyond the database suggest atypical gait patterns.
Practical note: even with imaging or clinical tests, variability is a useful indicator of fall risk when walking in real-world environments.
Example walkthrough (from a PhD study): a pressure-sensitive walkway captured multiple steps of an amputee, illustrating how to compute step length and its variability from raw footprints; the narrative emphasizes practical measurement of variability and its association with past falls.
Takeaway: increased gait variability is not inherently bad, but abnormally high variability, especially in safe environments, signals potential instability and falls risk; variability can be used to guide interventions.
Muscle activation and EMG changes with aging
In older adults, there is evidence of muscle over-activation and altered synergy patterns during gait, possibly due to changes in somatosensory feedback or guarded postures.
Muscles with notable changes (highlighted in red in the lecture) include:
Tibialis anterior (often reported as over-activation during specific gait phases)
Biceps femoris (short head or long head depending on phase)
Rectus femoris
Peroneus longus
Gastrocnemius (gastroc) with over-activation around heel strike
Functional consequences:
Reduced push-off power from plantar flexors (i.e., weaker or less effective toe-off during late stance).
Reduced quadriceps activation during late stance/early swing, affecting leg advancement.
The overall pattern reflects a shift in when and how muscles fire during the gait cycle, contributing to a stiffer, guarded gait in older adults.
This altered neuromuscular control can be linked to reduced somatosensory feedback and the need to protect the body from instability.
Falls and muscle coordination:
A critical component of fall prevention is the ability to activate the correct muscle sequences in the right order (e.g., hip flexors for swing, ankle plantar flexors for stance) to recover from trips.
The magnitude and rate of force development (torque) are slower in older adults, not just the sheer strength of the muscle. Torque generation is a product of moment arm and force:
tau = r x F
Slower torque development reduces the speed and effectiveness of protective responses.
Perturbation training as a preventive strategy:
Training that includes perturbations (e.g., controlled nudges, treadmill perturbations, or harness-supported environments) helps people learn to recruit the key muscles rapidly and efficiently to prevent a fall.
Practically, perturbations mimic trips and force individuals to adapt to maintain balance.
Slip response considerations:
Slips require rapid, well-timed engagement of ankle and knee strategies to prevent a fall; with aging, the protective response can be less efficient, and older adults may increase co-activation around the ankle and knee and adopt shorter steps on slippery surfaces to reduce risk.
Falls in aging: epidemiology and prevention concepts
Fall aetiology in older adults is multifactorial: trips, slips, environmental hazards, and systemic factors.
Trip-related falls account for ~35%-47% of falls in older adults.
Slip-related falls account for roughly 27%-32% of falls.
Sex differences: data suggest females may have a higher fall risk, potentially about four times greater in some datasets; potential contributing factors include hormonal changes, body composition, and muscle properties.
Core fall-prevention targets include improving rapid, coordinated muscle responses (hip flexors for swing, ankle plantar flexors for push-off) and enhancing protective reflexes through targeted training (e.g., perturbation training).
Key concepts in fall recovery:
It is not just strength but the timing and magnitude of torque generation that matter (i.e., how quickly muscles can generate the necessary forces).
The swing leg hip flexors and stance leg ankle plantar flexors are particularly critical in preventing a fall after a trip.
Older adults typically show slower torque generation and slower force development, which reduces their protective response speed.
Perturbation training options in practice:
Therapist-assisted perturbations in a controlled setting (e.g., harness systems that prevent actual falls) or altered ground perturbations on specialized treadmills.
The goal is to train efficient, rapid recruitment of the hip flexors and plantar flexors to counter perturbations.
Trips vs. slips: mechanisms and training implications
Trips: Require timely activation of hip flexors (swing leg) and ankle plantar flexors (stance leg) to clear the foot and re-establish stable gait.
The quality of the response depends on the magnitude and rate of muscle torque development; older adults show slower torque generation.
Slips: Involve recovery of the foot after the sudden loss of friction; a slip can lead to a subsequent trip if the leg is swinging forward.
Protective responses often include co-activation around the ankle and knee and adopting shorter steps to stabilize the base of support.
Training implications: Interventions should focus on rapid, coordinated muscle recruitment and not just isolated strengthening.
Perturbation-based training can help adults learn to respond more effectively to trips and slips in everyday environments.
Sensory factors influencing gait with aging
Somatosensorial (somatosensory input): Peripheral neuropathy reduces tactile feedback and proprioception, often accelerated by diabetes. Consequences include slower fast-walking speeds and higher fall risk: Vision and proprioception interplay in foot placement and ground contact; neuropathy can lead to flatter foot contact and altered foot mechanics.
Example image summary: peripheral neuropathy can show reduced plantar flexion push-off and dorsiflexion at heel strike, with a flatter foot contact and altered foot orientation during gait.
Vision: Visual changes with aging affect the ability to detect obstacles and plan reactive steps; nighttime walking increases risk due to reduced lighting.
Those with compromised vision or poor tug test performance tend to walk more slowly and with heightened guarding behaviour.
Vestibular function: Vestibular decline with age is linked to reduced gait speed and stability; vestibular cues are used to maintain balance during movement.
Cognitive changes and gait
Normal aging is associated with some cognitive change, and gait becomes more automated but attentional demands can rise with age, especially for safety.
Dual-tasking impact on gait: Walking while performing a cognitive task (e.g., serial subtractions by seven) increases attentional demands and reduces gait stability.
Example task: serial subtractions by seven while walking is used to probe cognitive-motor resource allocation and to assess dual-task costs.
A practical metric: Dual-task cost (DTC) can be defined as:
DTC = Psingle – Pdual / Psingle x 100%,
where P denotes performance (e.g., speed, accuracy) under single-task vs. dual-task conditions.
Training implications include integrating walking practice with cognitive tasks to promote automatization and enhance safe dual-task performance.
Other factors that affect gait in older adults
Pain and musculoskeletal discomfort can alter walking patterns (guarded or protective strategies).
Cardiopulmonary limitations can limit endurance and walking speed.
Fear of falling, anxiety, and previous falls influence gait and caution levels.
Medications may affect balance, alertness, and coordination.
Footwear quality and footwear choices (e.g., slippers) influence gait safety and stability.
Psychiatric factors (e.g., depression) can also affect motivation, energy, and gait patterns.
Environment and mobility: stairs, balance, and backward walking
Stairs: Falls on stairs account for about 10% of fall-related deaths, which is notable given the relatively small proportion of daily stair use.
Descent is more hazardous than ascent, by a factor of ~4x, due to greater demands on ankle/ knee/hip control and reduced sight lines.
Typical age-related changes on stairs include reduced cadence, longer foot clearance, and more posterior foot placement; older adults often use a wide base of support and two-handed handrail, with cautious foot placement and sometimes external rotation of the stepping foot.
Backwards walking: Older adults typically show reduced stride length when walking backwards and often increase cadence to go faster without increasing step length.
There is reduced hip flexion, knee flexion, and ankle flexion when stepping backwards, and reduced hip extension in backward walking.
These patterns reflect decreased confidence and altered motor control in the reverse gait task.
Practical implications for assessment and intervention
When evaluating gait in older adults, consider multiple interacting mechanisms: vision, somatosensorial, vestibular function, cognition, pain, fatigue, medications, footwear, and psychological factors.
Distinguish primary aging changes from secondary, potentially modifiable factors (nutrition, exercise, stress management, diabetes control, vascular health) to tailor interventions.
Interventions should address not only strength but also the speed and timing of torque development (i.e., the ability to recruit key muscles quickly and in the correct order).
Incorporate perturbation-based and task-specific training to improve reactive balance, hip flexor and ankle plantar flexor recruitment, and gait adaptability in real-world environments.
In daily practice, encourage safe exploration of real-world tasks (stairs, curb negotiation, stairs descent, walking on uneven surfaces) with appropriate safety supports (harnesses, rails) during rehabilitation to build confidence and reduce fall risk.
Summary and takeaways
Older adults commonly show slower gait, shorter step length, reduced cadence, and longer double-support time; these changes are related and can be more pronounced in females due to hormonal/muscle-property differences.
Kinematic changes include reduced flexion at the hip/knee/ankle, decreased dorsiflexion during late stance, and reduced vertical/lateral head movement, contributing to lower foot clearance and increased tripping risk.
Muscle activation patterns in aging show over-activation in several muscles (e.g., gastrocnemius, peroneus longus, tibialis anterior, rectus femoris, biceps femoris) with reduced push-off power and altered timing; torque development is slower rather than just weaker muscle strength.
Falls are a major issue; trips (~ 35%-47%) and slips (~ 27%-32%) are common causes, with sex differences and context-specific risks. Prevention focuses on rapid muscle recruitment and perturbation-based training.
Sensory (somatosensory, vision, vestibular) and cognitive changes contribute to gait alterations; dual-task declines reveal limited cognitive resources for safe walking, emphasising the importance of rehabilitation that integrates motor with cognitive demands.
Environment-specific mobility (stairs, backward walking) presents unique challenges; descent on stairs is particularly hazardous and may require specific training and safety strategies.
Clinicians should assess a broad range of underlying mechanisms and tailor interventions to improve safety, independence, and quality of life for older adults.
