The cause of a maximum velocity error where the lead leg's forward swing is too wide with a flat foot plant is due to which factors?

The cause of a maximum velocity error where the lead leg's forward swing is too wide with a flat foot plant is due to which factors?

• A. Trunk and Thigh weakness; fatigue.
• B. Excessive shoulder movement; insufficient shoulder joint flexibility.
• C. Inadequate hip stability.
• D. Poor ankle mobility.

Answer: (A)

The idea being tested is how weakness and fatigue in the trunk and proximal leg lead to a specific sprinting error at maximum velocity. When the trunk and thigh muscles are weak, and fatigue is present, central stability and hip–pelvis control decline. That shaky stability makes it hard to keep the lead leg moving in a compact, efficient arc, so the leg ends up swinging out wider rather than cutting straight forward. With a wide swing, the foot often lands more flat-footed, because the control and timing needed to land on a forefoot or midfoot with a quick transition are lost. Fatigue worsens this by reducing neuromuscular coordination and timing, so the breakdown in form becomes even more pronounced as velocity increases. The other factors mentioned—excessive shoulder movement or limited shoulder flexibility (affecting arm drive rather than leg path), inadequate hip stability (relevant but often a manifestation of proximal weakness), and poor ankle mobility (influencing foot strike timing more than the width of the leg swing)—are less directly linked to the specific pattern described. The combination of trunk and thigh weakness with fatigue best explains both the wide forward swing of the lead leg and the flat foot plant observed at max velocity.

The idea being tested is how weakness and fatigue in the trunk and proximal leg lead to a specific sprinting error at maximum velocity. When the trunk and thigh muscles are weak, and fatigue is present, central stability and hip–pelvis control decline. That shaky stability makes it hard to keep the lead leg moving in a compact, efficient arc, so the leg ends up swinging out wider rather than cutting straight forward. With a wide swing, the foot often lands more flat-footed, because the control and timing needed to land on a forefoot or midfoot with a quick transition are lost. Fatigue worsens this by reducing neuromuscular coordination and timing, so the breakdown in form becomes even more pronounced as velocity increases.

The other factors mentioned—excessive shoulder movement or limited shoulder flexibility (affecting arm drive rather than leg path), inadequate hip stability (relevant but often a manifestation of proximal weakness), and poor ankle mobility (influencing foot strike timing more than the width of the leg swing)—are less directly linked to the specific pattern described. The combination of trunk and thigh weakness with fatigue best explains both the wide forward swing of the lead leg and the flat foot plant observed at max velocity.