Related Experiment Video
Updated: Aug 8, 2026
Methods to Quantify Pharmacologically Induced Alterations in Motor Function in Human Incomplete SCI
Published on: April 18, 2011
Changes in Iliopsoas Muscle Activity and Hip/Pelvic Kinematics With Variations in Step Length and Cadence at a Fixed
Takumi Jiroumaru1, Michio Wachi1, Yutaro Hyodo1
1Department of Physical Therapy, Bukkyo University, Kyoto, JPN.
Background:
Older adults often compensate for reduced mobility by adopting shorter steps and a faster cadence, which may alter muscle recruitment and joint kinematics. The iliopsoas, a key muscle for leg swing and posture control, is particularly affected. Understanding its role across different gait patterns may help improve gait training and fall prevention.
Purpose:
To investigate how step length and cadence influence iliopsoas muscle activation and hip/pelvic kinematics during treadmill walking at a constant speed.
Methods:
Ten healthy young men walked on a treadmill at 5 km/h under three conditions: (1) Step-Length Increased Walking (SL), longer steps with lower cadence; (2) Normal Walking (N), self-selected gait; and (3) Pitch Increased Walking (P), shorter steps with higher cadence. Iliopsoas activity was measured using surface electromyography, and hip/pelvic motion was captured using 3D motion analysis. The gait cycles were divided into four functional phases for phase-specific analysis. Nonparametric tests were used to compare muscle activity across conditions.
Results:
Iliopsoas activity was significantly higher during the early (Phase 1) and late stance (Phase 2) in both the SL and P conditions than in the N condition. During the late swing (Phase 4) period, the SL condition elicited the greatest iliopsoas activation accompanied by increased hip flexion and pelvic tilt. This phase showed the strongest effect size among all phases, highlighting the critical role of iliopsoas during terminal swing. P walking also showed elevated iliopsoas activation during the stance, likely due to the faster step cycle.
Conclusion:
The findings suggest that step length and cadence influence the timing and magnitude of iliopsoas activation. Longer steps increase activation during the late swing phase, while a higher cadence enhances activation during stance. Phase-specific training targeting iliopsoas strength and hip flexion mobility may help improve gait performance.
Related Concept Videos
01:20Motor Unit Stimulation
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
01:22Muscle Stimulation Frequency
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
01:32Types of Skeletal Muscle Fibers
Fast-twitch fibers
Fast-twitch fibers, or Type II fibers, are designed for quick, powerful bursts of speed and strength. They reach peak tension within approximately 0.01 seconds following stimulation. Characterized by a large diameter and densely packed myofibrils, these fibers contain...
01:27Exercise and Muscle Performance
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
01:25Smooth Muscle Contraction
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
01:20Exercise and Cardiovascular Response
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...