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Start Position

• Common Setups:
  In Olympic weightlifting and strength training, the clean typically starts from the floor but may also begin from positions below the knee, above the knee, or below the hip fold.

  • Static Starts: From floor, blocks, safety bars, or a stationary hang—focuses on controlled force application.

  • Dynamic Starts: Uses a countermovement to preload muscles and tendons for greater elastic energy storage and subsequent power output.

• Biomechanics:

  • Newton’s First Law applies—the bar remains at rest until upward force exceeds its weight.

  • The athlete must set the barbell’s center of mass over the mid-foot to optimize leverage and minimize torque on the lower back.

  • Initial Force Equation: F=m×a — More applied force means greater bar acceleration in the first pull.

End Position of the Clean (Catch Phase)

• Description:
  The clean ends with the barbell received in the front rack position into a squat—this phase develops force absorption qualities as the lifter decelerates the bar’s downward motion.

  • For some, this position stresses the wrists and shoulders due to high torque demands at those joints.

  • Alternatives like the jump shrug or high pull remove the catch phase while still generating high force–velocity outputs in the concentric phase.

  • The athletes arms pull you under, but your legs and core absorb the load by rapidly decelerating the bar

• Biomechanics:

  • Impulse–Momentum: F×t=m×Δv — the longer you apply force in the pull, the greater the bar’s velocity before you drop under it.

  • In the catch, eccentric muscle action decelerates the bar.

  • Shoulders and wrists must counteract rotational forces to stabilize the load.

Jerk Phase

• Dip & Drive:
  From the front rack, the lifter dips slightly (about 10% body height) before driving upward. This phase stores elastic energy in the quads and hips, contributing to explosive extension.

  • Torque at Knees: τ=F×r— shorter moment arms reduce joint stress, longer arms require more muscular force.

  • Newton’s Third Law: The ground pushes back with equal force, propelling both lifter and bar upward.

• Push Under & Lockout arms:
  After the drive, the lifter quickly repositions under the bar in either a split or squat stance.

  • Rotational Stability: Keeping the bar’s center of mass vertically aligned with the base of support prevents tipping.

  • Joints: Shoulders, elbows, and wrists produce isometric and concentric contractions to stabilize and lock the bar overhead.