Advisor Information

KOTA TAKAHASHI

Location

Room 231

Presentation Type

Oral Presentation

Start Date

1-3-2019 9:00 AM

End Date

1-3-2019 10:15 AM

Abstract

Flexor hallucis longus (FHL) is a multiarticular muscle that possesses the potential to alter foot’s functional and mechanical behavior, since it performs multiple significant functions during walking (e.g supports the medial longitudinal arch of the foot).The purpose of this study was to determine if the functional changes of the FHL are associated with the foot’s adaptations to the mechanical demands of walking. Backward walking is an experimental method capable of altering how the forces propagate underneath the foot and disrupting the mechanical function of the FHL muscle. We hypothesized that: (1) the muscle activity of the FHL will increase during backward walking, compared to forward walking (2) the increased muscle activity will correlate to changes in foot’s mechanical work production. Healthy young participants will walk (forward & backward) barefoot for 3 minutes on an instrumented treadmill at five different walking speeds: 0.46, 0.92, 1.25, 1.56, 1.85 m/s. Via ultrasound, we will compute muscle fascicle length, pennation angle, and maximum shortening velocity and isometric force of the FHL. By using EMG sensors we will measure muscle activation. To relate FHL fascicle force and muscle activation, we will compute force per unit activation, which is the ratio of integrated force to integrated EMG during stance. A unified deformable segment analysis will capture the summed mechanical contribution of all the structures of the foot (i.e., fat pads, muscles, tendons). Currently, we are analyzing piloting data. The results can lay the ground for innovative interventions for musculoskeletal pathologies of the ankle-foot complex.

COinS
 
Mar 1st, 9:00 AM Mar 1st, 10:15 AM

The Energy Paradox of the Ankle-Foot Complex during Human Walking

Room 231

Flexor hallucis longus (FHL) is a multiarticular muscle that possesses the potential to alter foot’s functional and mechanical behavior, since it performs multiple significant functions during walking (e.g supports the medial longitudinal arch of the foot).The purpose of this study was to determine if the functional changes of the FHL are associated with the foot’s adaptations to the mechanical demands of walking. Backward walking is an experimental method capable of altering how the forces propagate underneath the foot and disrupting the mechanical function of the FHL muscle. We hypothesized that: (1) the muscle activity of the FHL will increase during backward walking, compared to forward walking (2) the increased muscle activity will correlate to changes in foot’s mechanical work production. Healthy young participants will walk (forward & backward) barefoot for 3 minutes on an instrumented treadmill at five different walking speeds: 0.46, 0.92, 1.25, 1.56, 1.85 m/s. Via ultrasound, we will compute muscle fascicle length, pennation angle, and maximum shortening velocity and isometric force of the FHL. By using EMG sensors we will measure muscle activation. To relate FHL fascicle force and muscle activation, we will compute force per unit activation, which is the ratio of integrated force to integrated EMG during stance. A unified deformable segment analysis will capture the summed mechanical contribution of all the structures of the foot (i.e., fat pads, muscles, tendons). Currently, we are analyzing piloting data. The results can lay the ground for innovative interventions for musculoskeletal pathologies of the ankle-foot complex.