Rowing · Trunk at Handle-Past-Knees

Why this matters

This is the second sequencing checkpoint. After the legs have finished (legs-down), the back is the next muscle group to deliver power. Catching the back mid-swing at the moment the handle passes the knees tells you whether the back actually started its job on time. A clean rower's back angle here will sit roughly halfway between the catch position and the finish layback.

Together with Body Angle at Legs-Down, this measurement triangulates the drive sequence. If both report "back still forward" → bum shoot. If both report "back already open" → the back ran early. If this one reports "back open" and legs-down reports "back held" → clean rower; the back swung between them as intended.

What good looks like

The torso is roughly halfway between the catch lean and finish layback. The arms are still mostly straight (the elbow draw doesn't start until the handle is past the knees). The legs are flat. The seat has reached approximately its back-stop position, and the handle is in the lower-rib zone but not yet at the body.

Common faults

• Back locked forward (< 5°) — the back hasn't started its swing yet. The finish will lack layback and power; the arms will end up doing the back's job.
• Already at finish layback (> 20°) — the back swung too aggressively too early. The arms must now over-pull to drag the handle the rest of the way, which fatigues the biceps and forearms. Often paired with a "thrown" back swing where the head pitches back.

Coaching cues

• "Knees down, then swing." Two beats: legs first, then the back.
• "Open with the chest, not the shoulders." Keeps the swing controlled by the hip extensors rather than the rhomboids.

Related measurements

• Body Angle at Legs-Down — preceding checkpoint. The body should have just started swinging between these two frames.
• Layback at Finish — where the swing should end.
• Elbow Flexion at Finish — confirms the arms came last (they should still be mostly straight here).