Knee Flexion

Seated Leg Curl

A practical movement guide for every Mission SOP that uses this exercise. Sets, reps, load, tempo, and purpose remain specific to each mission and phase.

Movement guide available

Anatomy map

Muscles involved

Primary Supporting
Option 2 custom anatomy illustration for Seated Leg Curl, with primary and supporting muscles highlighted
PrimaryHamstrings
SupportingGluteal musclesSpinal erectors

ShaOS custom anatomy illustration. Visual reference only; movement coaching and muscle classifications remain defined by the Exercise Library.

Description

A machine-based knee-flexion exercise that trains the hamstrings in a lengthened seated position with controlled, repeatable resistance.

Setup & Execution

  1. Adjust the seat so the machine pivot aligns with the knee and the lower pad rests above the heel.
  2. Secure the thigh pad, sit tall against the backrest, and begin with the knees comfortably extended.
  3. Curl the heels down and back as far as possible without the hips lifting.
  4. Pause, then return slowly to the starting position while maintaining tension.

Coaching Cues

  • Keep hips pinned down.
  • Curl through the heels.
  • Control the return to full length.

Common Mistakes

  • Using momentum at the start.
  • Allowing the hips to lift from the seat.
  • Cutting the eccentric range short.

Movement media

See the movement

Reviewed short loop
Published media
Short silent loop · 5 seconds
Reviewed
Jul 17, 2026
Video source
Open source record
30–60 second tutorialplanned
Setup angleplanned
Side angleplanned
Key cue overlayplanned
Captionsplanned
Transcriptplanned

Accessible movement summary

Adjust the seat so the machine pivot aligns with the knee and the lower pad rests above the heel. Secure the thigh pad, sit tall against the backrest, and begin with the knees comfortably extended. Curl the heels down and back as far as possible without the hips lifting. Pause, then return slowly to the starting position while maintaining tension.

Key cue: Keep hips pinned down.

The production indicators above are roadmap states, not claims that multi-angle footage, overlays, captions, or a narrated transcript are already available.

Adapt the movement

Regressions & alternatives

Preserve the movement pattern while matching current capacity, available equipment, and the mission environment.

Regression

Stability-ball leg curl

Progression

Nordic hamstring eccentric

Home gym

Slider leg curl

Commercial gym

Single-leg seated leg curl

Used in

Linked Mission SOPs

Lower Strength & CarriesFoundationLower Hypertrophy & CapacityAscent