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Updated: May 9, 2026
Lower-Limb Biomechanical Characteristics Associated with Unplanned Gait Termination Under Different Walking Speeds
Published on: August 25, 2020
Walking speed effects on the lower limb electromyographic variability of healthy children aged 7-16 years
Oren Tirosh1, Morgan Sangeux, Matthew Wong
1Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville 3052, Victoria, Australia; Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Footscray, Victoria, Australia.
Insights
Surface electromyography (sEMG) in typically developing children shows greater lower limb muscle variability in younger children (7-9 years) and during non-comfortable walking speeds. This impacts interpreting sEMG in cerebral palsy (CP).
Area of Science:
- Pediatric Neurology
- Movement Science
- Biomedical Engineering
Background:
- Surface electromyography (sEMG) is crucial for assessing gait in children with cerebral palsy (CP).
- Reliable interpretation of sEMG in CP requires understanding normative data from typically developing (TD) children.
- Age-related variability in sEMG patterns of TD children is not fully characterized.
Purpose of the Study:
- To quantify and compare the variability of sEMG measures in the lower limb muscles of TD children across different age groups and walking speeds.
- To establish normative variability data for sEMG linear envelope (LE) and Instantaneous Mean Frequency (IMNF) during gait.
Main Methods:
- Variance ratio analysis was used to assess inter-trial variability of sEMG LE and IMNF in lower limb muscles.
- TD children were grouped into three age categories (7-9, 10-12, 13-16 years).
- sEMG data were collected during slow, comfortable, and fast walking conditions.
Main Results:
- Younger children (7-9 years) exhibited significantly greater sEMG variability compared to older children (13-16 years).
- Walking at slow and fast speeds resulted in significantly greater variability than comfortable speed walking, particularly in the 7-9 age group.
- IMNF variability was significantly higher than LE variability in key lower limb muscles (Tibialis Anterior, Biceps Femoris, Vastus Lateralis, Rectus Femoris).
Conclusions:
- Muscle activation patterns, as measured by sEMG, mature later in childhood than kinematic gait patterns.
- Children under 10 years show more variable sEMG patterns during gait, especially at non-preferred speeds.
- Increased caution is advised when comparing sEMG data from young children (under 10) with TD peers to accurately diagnose and manage CP.
Abstract:
The evaluation of surface electromyography (sEMG) is commonly performed in children with cerebral palsy (CP) and reliable interpretation necessitates knowledge of the variability in age-matched, typically developing (TD) children. Variance ratio was calculated for inter-trial sEMG linear envelope (LE) and the Instantaneous Mean Frequency (IMNF) variability in the lower limb muscle in TD children, in three different age groups during slow, comfortable speed, and fast walking. Significantly greater variability was found in the 7-9 group compared to the 13-16 years. Variability during both slow and fast walking was significantly greater compared to comfortable speed walking and was profound in the 7-9 year age group. Variability of the IMNF was significantly greater than LE in the Tibialis-Anterior, Biceps-Femoris (BF), Vastus-Lateralis (VL), and Rectus-Femoris (RF). Clinical implications are that children under 10 years are more variable than older children when walking either slower or faster than self-selected walking speed. This suggests that muscle activation patterns in gait mature at a later stage of childhood than do kinematic gait patterns. Greater precaution, therefore, is needed when comparing sEMG patterns of less than 10 years of age patient and TD children.
