Aquatic Kinesiology & Biomechanics Flashcards

In aquatic biomechanics, the 'metacentric couple' refers to the rotational tendency created by:

Answer: The offset between the center of gravity and center of buoyancy

The metacentric couple is the rotational force pair produced when the center of gravity and center of buoyancy are not vertically aligned, tending to rotate the body.

When a therapist instructs a patient to 'streamline' a limb by moving the hand blade-first through water, which type of drag is primarily reduced?

Answer: Form drag

Form drag (pressure drag) is reduced by streamlining because presenting a narrower cross-section to the direction of movement decreases the pressure differential across the limb.

Metacentric height in aquatic biomechanics is best defined as:

Answer: The vertical distance between the metacenter and the center of gravity, indicating rotational stability

Metacentric height measures the distance between the metacenter and center of gravity; a positive value indicates the body will self-correct rotational displacement, while a negative value indicates instability.

Turbulent flow conditions created during aquatic therapy are most clinically valuable for:

Answer: Increasing resistance and balance challenge through unpredictable forces

Turbulent flow creates multidirectional, unpredictable resistance forces that challenge proprioception and balance, making it therapeutically useful for neuromuscular training.

The concept of 'added mass' in aquatic biomechanics is most accurately described as:

Answer: The mass of surrounding water that must be accelerated along with a moving body segment

Added mass (virtual mass) is the volume of water entrained by a moving limb that must be accelerated together with the limb, increasing the effective inertia of the movement.

Compared to land-based exercise, aquatic exercise most commonly demonstrates which pattern of muscle activation?

Answer: Altered co-contraction patterns with reduced eccentric demands during buoyancy-assisted phases

Buoyancy assists upward movements, reducing the eccentric demand normally required to control descent against gravity, thereby altering co-contraction patterns compared to land exercise.

Frontal resistance (form drag) during upper extremity aquatic exercise is greatest when the patient moves the limb:

Answer: Perpendicular to the direction of movement with maximum surface area exposed

Form drag is maximized when the limb presents its largest cross-sectional area perpendicular to the direction of movement, intercepting the maximum volume of water.