Seated Single Leg Knee Flexion
Seated Single Leg Knee Flexion Exercise Description
Seated Single Leg Knee Flexion is a bodyweight hamstring curl performed while sitting on a chair or bench. The movement primarily targets the hamstrings (biceps femoris, semitendinosus, semimembranosus), with assistance from the gastrocnemius as it crosses the knee to help flexion. You’ll slide one heel along the floor to bend the knee, keeping the torso upright and the thigh relatively still. This unilateral setup promotes balanced control side‑to‑side and allows you to focus on smooth, pain‑free range of motion without external load. Maintain a neutral spine and steady pelvis throughout so the work stays at the knee rather than the low back or hips. Controlled tempo and consistent heel contact with the floor help you feel the hamstrings initiating and sustaining the pull.
- Muscle Groups: Hamstrings
- Target Muscles: Biceps Femoris - Long Head, Semimembranosus, Semitendinosus
- Assisting Muscles: Gastrocnemius - Medial Head
- Stabilizing Muscles: Iliocostalis, Longissimus, Multifidus, Transversus 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: Male
How To Do The Seated Single Leg Knee Flexion Exercise
‘- Sit tall near the front edge of a sturdy chair; ribs stacked over pelvis, shoulders down and back.
– Plant one foot under the knee for support. Extend the working leg forward with the heel lightly on the floor and toes pulled up (dorsiflexed).
– Brace the core. Keep hips level and thigh of the working leg facing straight ahead.
– Press the heel gently into the floor and slide it toward you by bending the knee. Keep the thigh relatively still.
– Track the knee in line with the middle of the foot; do not let it collapse inward.
– Stop when the heel approaches the chair or your comfortable range without losing posture.
– Slowly slide the heel forward to return, maintaining control and heel contact.
– Breathe out as you pull the heel in; breathe in as you return.
– Repeat on the other leg with the same alignment and control.
Seated Single Leg Knee Flexion Tips
‘- Sit tall near the front edge of the chair with ribs stacked over pelvis and shoulders down and back.
– Keep your torso upright and spine neutral so the work stays at the knee, not the low back or hips.
– Plant the non-working foot directly under the knee to give you stable support.
– Brace your core and keep your hips level to maintain a steady pelvis.
– Extend the working leg forward with the heel lightly on the floor and toes pulled up (dorsiflexed).
– Keep the thigh of the working leg facing straight ahead and relatively still as you move.
– Press the heel gently into the floor and keep heel contact throughout the slide in and out.
– Track the knee in line with the middle of the foot and avoid letting it collapse inward.
– Move with a controlled tempo both pulling in and returning, stopping before you lose posture or comfortable range.
– Breathe out as you pull the heel in and breathe in as you slide it forward to return.
Seated Single Leg Knee Flexion Beginner Introduction
Seated Single Leg Knee Flexion is a simple, chair-based hamstring curl that uses only bodyweight and floor friction. One leg acts as the mover while the other leg and the seat provide support. From an upright sitting position, the working heel rests lightly on the ground with toes angled upward. The heel then glides backward toward the chair and forward again, bending and straightening the knee while the thigh remains nearly in place. This sliding action places the main challenge on the hamstrings at the back of the thigh, with help from the calf as it crosses the knee.
Because only one leg moves at a time, this exercise highlights side-to-side differences in strength and control. The upright posture with a steady lower back and hips encourages the effort to come from the knee joint instead of the spine or hip area. A smooth, unhurried rhythm and steady heel contact with the floor support a comfortable range of motion, making it easier to sense the hamstrings initiating and sustaining the pull through each repetition.