Summary Concepts of Human Movement Science
Stability – Jaap van Dieën
Defining stability
- Stability appears to be related to the ability to control movement, of the
whole body, to be precise enough to hit the target in shooting or to
prevent falling, or of a joint to allow precise movement or to prevent
(re)injury (Stability text, van Dieën, 2020)
- Core stability = the body’s ability to maintain or restore an equilibrium
position of the trunk (= also known as the core) after perturbations (Zazulak
et al., 2007). > a disturbance of a position and you want to come back to that
position.
- ‘An equilibrium position’ > static concept > (quasi) static analysis. > not
about dynamic movements.
- Merriam-Webster dictionary: the property of a body that causes it when
disturbed from a condition of equilibrium or steady motion to develop forces
or moments that restore the original condition. > Stability means you can
recover from the perturbation.
- Perturbation = any force, moment or torque causing an unintended change
in the current equilibrium which is known as the planned state of a system
Meaning: core stability is about the ability to deal with perturbations a system
is referred to as stable when it is able to deal with perturbations: new behavior is
more or less the same as before the perturbation
Trunk stability and performance
(lack of trunk control may affect performance)
- Precision > gun shooting. > you have to keep your trunk in the same
position. > when you lie on the floor it comes much more easy because
your trunk has more support.
- Balance > mountain climbing
- Ballistic movement > Accelerate your leg foward. (soccer) > you want
your trunk stable to stay in a upright position.
Trunk stability and injury
- 23 videotapes of athletes captured during an ACL
injury requiring reconstruction compared to similar
landings without injury
- Lateral trunk and knee abduction are important
components of the ACL injury mechanism. Lateral
trunk was different
- Lack of control over trunk movement may cause
large moments around lower extremity joints
- Angle between gravity and trunk was bigger in athletes with ACL injury
- Landing on one leg ground reaction force directed as green arrow
moment will rotate the upper body in right direction.
- Middle figure center of mass is approximately above the knee and ankle
during landing no moment around the knee and ankle.
- Right figure trunk too far to the right, moment is big relative to the knee
you don’t have the right muscles on that sight of the knee (only
ligaments that counteract the moment)
Stability – Jaap van Dieën
Defining stability
- Stability appears to be related to the ability to control movement, of the
whole body, to be precise enough to hit the target in shooting or to
prevent falling, or of a joint to allow precise movement or to prevent
(re)injury (Stability text, van Dieën, 2020)
- Core stability = the body’s ability to maintain or restore an equilibrium
position of the trunk (= also known as the core) after perturbations (Zazulak
et al., 2007). > a disturbance of a position and you want to come back to that
position.
- ‘An equilibrium position’ > static concept > (quasi) static analysis. > not
about dynamic movements.
- Merriam-Webster dictionary: the property of a body that causes it when
disturbed from a condition of equilibrium or steady motion to develop forces
or moments that restore the original condition. > Stability means you can
recover from the perturbation.
- Perturbation = any force, moment or torque causing an unintended change
in the current equilibrium which is known as the planned state of a system
Meaning: core stability is about the ability to deal with perturbations a system
is referred to as stable when it is able to deal with perturbations: new behavior is
more or less the same as before the perturbation
Trunk stability and performance
(lack of trunk control may affect performance)
- Precision > gun shooting. > you have to keep your trunk in the same
position. > when you lie on the floor it comes much more easy because
your trunk has more support.
- Balance > mountain climbing
- Ballistic movement > Accelerate your leg foward. (soccer) > you want
your trunk stable to stay in a upright position.
Trunk stability and injury
- 23 videotapes of athletes captured during an ACL
injury requiring reconstruction compared to similar
landings without injury
- Lateral trunk and knee abduction are important
components of the ACL injury mechanism. Lateral
trunk was different
- Lack of control over trunk movement may cause
large moments around lower extremity joints
- Angle between gravity and trunk was bigger in athletes with ACL injury
- Landing on one leg ground reaction force directed as green arrow
moment will rotate the upper body in right direction.
- Middle figure center of mass is approximately above the knee and ankle
during landing no moment around the knee and ankle.
- Right figure trunk too far to the right, moment is big relative to the knee
you don’t have the right muscles on that sight of the knee (only
ligaments that counteract the moment)
