Sitting Single Leg Knee Flexion
Sitting Single Leg Knee Flexion Exercise Description
Sitting Single Leg Knee Flexion strengthens the posterior thigh by actively bending the knee against floor friction while seated. The primary movers are the hamstrings (biceps femoris, semitendinosus, semimembranosus), with assistance from the gastrocnemius, while the trunk and hips stay stable. Because you’re seated with the hip flexed, the focus is on controlled knee flexion without relying on momentum, making it a clear, low-load way to groove hamstring activation. Keeping the thigh still minimizes hip motion, helping you isolate the knee joint and maintain neutral spine alignment. This bodyweight variation is useful when equipment isn’t available and when you want precise control over range of motion and joint tracking.
- Muscle Groups: Hamstrings
- Target Muscles: Biceps Femoris - Long Head, Semimembranosus, Semitendinosus
- Assisting Muscles: Gastrocnemius - Medial Head
- Stabilizing Muscles: Gluteus Medius, Multifidus, Rectus Abdominis
- Body Area: Lower Body
- Body Parts: Legs, Upper Legs
- Body Surface: Back
- Body Symmetry: Unilateral
- Equipment: Bodyweight
- Exercise Patterns: Other
- Exercise Type: Strength
- Functional Grouping: Hip Extensors, Knee Flexors
- Joint Involvement: Single-joint
- Muscle Location: Inner Hamstring, Outer Hamstring
- Movement Direction: Horizontal
- Muscle Position: Posterior
- Gender: Female
How To Do The Sitting Single Leg Knee Flexion Exercise
‘- Sit tall near the front of a sturdy chair; shoulders down, ribs stacked, neutral spine.
– Place both feet hip-width. Slide the working leg’s heel slightly forward on the floor; keep toes pointing forward.
– Keep hips level and the working thigh vertical; avoid rotating or hiking the pelvis.
– Press the working heel lightly into the floor to create friction, then pull the heel toward the chair by flexing the knee.
– Keep the foot in contact with the floor and the knee tracking over the middle toes; avoid caving inward or flaring outward.
– Stop when the heel is under the knee or just before it reaches the chair, maintaining upright posture.
– Briefly squeeze the back of the thigh, then slowly let the heel slide forward to the start under control.
– Keep breathing; avoid holding your breath or leaning back to gain leverage.
– Switch legs, maintaining the same alignment and control on both sides.
Sitting Single Leg Knee Flexion Tips
‘- Sit tall near the front of the chair with shoulders down, ribs stacked, and a neutral spine.
– Keep both feet hip-width apart and the working leg’s toes pointing straight forward.
– Keep the working thigh vertical and hips level; avoid rotating or hiking the pelvis.
– Press the working heel lightly into the floor to create friction before you start pulling.
– Pull the heel toward the chair by actively flexing the knee while keeping the foot in contact with the floor.
– Keep the knee tracking over the middle toes; avoid letting it cave inward or flare outward.
– Stop the slide when the heel is under the knee or just before it reaches the chair, maintaining an upright posture.
– Briefly squeeze the back of the thigh at the end of the pull before returning.
– Let the heel slide forward back to the start position slowly and under control.
– Keep breathing throughout and avoid leaning back to gain leverage on the movement.
Sitting Single Leg Knee Flexion Beginner Introduction
Sitting Single Leg Knee Flexion is a simple seated drill that targets the back of one thigh at a time using only bodyweight and floor resistance. From a chair, one heel glides along the ground toward the seat as the knee bends, while the other leg stays parked for support. The trunk stays upright and steady, with the hips flexed, so the action centers on the knee rather than the hip. This setup places attention on the hamstrings, with some help from the calves, without adding extra load.
Because the heel slides against the floor, the movement naturally encourages slow, deliberate effort instead of swinging or using momentum. The working thigh remains in place so the hips and lower back stay relatively quiet, helping the knee follow a consistent path. This makes the exercise useful in situations where equipment is limited and when a very controlled, single-leg challenge is preferred, such as when fine-tuning how the back of the thigh engages through a comfortable bending range.