The single leg hamstring bridge takes the hamstring bridge (covered in the hamstring bridge article on this site) and removes the support of one leg, placing the entire posterior chain demand on a single limb. The result is not simply a harder version of the same exercise: the unilateral loading reveals side-to-side hamstring strength asymmetries that the bilateral version conceals, develops the pelvic control that is absent when both legs share the load, and provides a training stimulus that is more specific to the single-leg demands of running and athletic movement.
How the Single Leg Version Differs From the Bilateral
Doubled load per leg: In the bilateral hamstring bridge, each leg shares approximately half the load. The single-leg version places the full body weight demand on one hamstring, approximately doubling the per-leg training stimulus.
Pelvic stability demand: With both legs extended in the bilateral version, the pelvis is inherently stable in the lateral direction. Remove one leg and the gluteus medius of the working side must work isometrically to prevent the pelvis from dropping on the non-working side. This pelvic stability demand is absent from the bilateral version.
Asymmetry revelation: The bilateral bridge allows the stronger leg to compensate for the weaker, masking side-to-side differences. The single-leg version immediately reveals which hamstring is weaker, which is particularly important for runners and athletes where hamstring asymmetry is a significant injury risk factor.
Anti-rotation core demand: The asymmetric loading of the single-leg bridge creates a rotational force on the pelvis and lumbar spine that the core must resist. This anti-rotation demand is absent from the bilateral version.
Muscles Targeted
Primary:
- Hamstrings (working leg): Work as the primary hip extensors and knee flexors simultaneously, as described in the hamstring bridge article on this site
- Gluteus medius (working leg): Works isometrically to maintain pelvic level throughout
Secondary:
- Gluteus maximus (working leg): Contributes to hip extension alongside the hamstrings
- Core (anti-rotation and anti-lateral-flexion): Resists the rotational and lateral forces of the asymmetric single-leg loading
- Gastrocnemius (working leg): Contributes to the knee flexion component
Step-by-Step Technique
Starting Position
- Lie flat on the back
- Both legs extended with heels on the floor, as for the bilateral hamstring bridge
- Extend both legs to the hamstring bridge foot position (nearly fully extended, approximately 150 to 160 degrees at the knee)
- Lift one leg off the floor and hold it either straight (extended toward the ceiling or at 45 degrees) or bent at 90 degrees of hip and knee flexion
The non-working leg position:
Straight leg extended (more demanding): The non-working leg is held straight in the air at approximately 45 degrees. This creates a greater asymmetric load on the working side and a larger anti-rotation demand on the core.
Bent knee (less demanding): The non-working leg maintains 90 degrees of hip and knee flexion (similar to the starting position of a single-leg glute bridge). This reduces the rotational demand and makes the exercise slightly more accessible.
Recommendation: Begin with the bent-knee position to establish the movement pattern, then progress to the straight-leg extended position.
The Bridge
- Engage the core gently
- Press through the heel of the working leg firmly into the floor
- Use the “drag the heel toward the hips” cue (without actually moving it) to pre-activate the hamstrings before lifting
- Drive the hips upward until the body forms a straight line from the working knee to the shoulders
- At the top, the pelvis must remain level: neither hip should be higher than the other
- Squeeze the hamstrings firmly at the top and hold for 1 to 2 seconds
- Lower slowly under control over 2 to 3 seconds
- Allow the hips to lightly touch the floor before the next rep
- Complete all reps on one side before switching
Key Technique Cues
Level pelvis at the top: The most critical cue specific to the single-leg version. The pelvis must remain horizontal at the bridge height. If the non-working side drops below the working side, the gluteus medius of the working leg is not maintaining pelvic level. This pelvic drop is the most common and most important error to identify and correct.
Heel drive, not toe drive: As with the bilateral hamstring bridge, the working foot contact must be through the heel. Any shift toward the toes reduces hamstring dominance and shifts the load toward the glutes.
No trunk rotation: The hips and shoulders should remain square throughout. Any rotation of the trunk or pelvis toward the working side indicates insufficient anti-rotation core stability.
Working leg shin angle: The shin of the working leg should be moderately angled (not vertical as in a glute bridge and not completely horizontal). If the foot is too close to the hips, the glutes dominate. If the legs are too straight, the hamstrings cannot maintain the bridge height.
Non-working leg still: The non-working leg should remain stationary throughout. If it moves or drifts, the balance and control of the exercise is disrupted.
Common Errors and Fixes
Error 1: Pelvic Drop on the Non-Working Side
What it looks like: The hip on the side of the lifted leg drops below the working hip at the top of the bridge.
Why it happens: The gluteus medius of the working leg is insufficient to maintain pelvic level under the unilateral loading.
Fix: Reduce the range of motion and only bridge to the height where the pelvis can remain level. Strengthen the gluteus medius with clamshells, lateral band walks, and single-leg glute bridges before progressing the single-leg hamstring bridge depth.
Error 2: Trunk Rotation
What it looks like: The body rotates toward the working side as the hips lift, with one shoulder rising off the floor.
Why it happens: The anti-rotation core is insufficient for the rotational forces of the single-leg loading.
Fix: Focus on keeping both shoulders flat on the floor throughout. Engage the core before the bridge and maintain the engagement through the full movement. If rotation persists, regress to the bilateral version until core anti-rotation strength is better established.
Error 3: Hamstring Cramping
What it looks like: The hamstring of the working leg cramps during or immediately after the exercise.
Why it happens: As with the bilateral hamstring bridge, cramping is common when first attempting the exercise, indicating the hamstrings are working in an unaccustomed manner. In the single-leg version, the doubled demand makes cramping even more likely on first attempts.
Fix: Reduce reps, stretch after each session, and build volume progressively. The cramping typically resolves within 1 to 2 weeks.
Error 4: Glute Rather Than Hamstring Dominance
What it looks like: The effort is felt primarily in the glutes rather than the hamstrings of the working leg.
Fix: Move the working foot slightly further from the hips and ensure heel-only contact. Use the pre-activation cue (deliberately tighten the hamstrings before lifting). If the hamstrings still cannot be felt as the primary working muscle, the foot position needs further adjustment.
Error 5: Hips Too Low at the Top
What it looks like: The hips do not reach the full straight-line position from the working knee to the shoulders, sagging significantly below.
Why it happens: The hamstring strength for the full range is not yet adequate, or the working foot is too far from the body.
Fix: Move the working foot slightly closer to the hips and build to the further position progressively. Alternatively, use the bilateral hamstring bridge to develop the foundational strength before attempting the single-leg version at full height.
Progressions
Level 1: Single Leg Hamstring Bridge With Bent Non-Working Knee
As described above. The non-working leg is held at 90 degrees of hip and knee flexion.
Sets and reps: 3 sets of 10 per side
Level 2: Single Leg Hamstring Bridge With Extended Non-Working Leg
The non-working leg is held straight at 45 degrees, increasing the asymmetric load and anti-rotation demand.
Sets and reps: 3 sets of 10 per side
Level 3: Single Leg Hamstring Bridge With Pause
Add a 3 to 5 second hold at the top position. The sustained pelvic level hold specifically develops the gluteus medius isometric endurance and the hamstring isometric strength at end range.
Sets and reps: 3 sets of 8 per side with 3-second hold
Level 4: Single Leg Hamstring Bridge With Slow Eccentric
Lower the hips over 5 to 6 seconds. The extended eccentric phase develops the hamstring’s eccentric control at long muscle lengths, which is specifically relevant to the deceleration phase of running and to hamstring strain prevention.
Sets and reps: 3 sets of 6 to 8 per side
Level 5: Single Leg Hamstring Bridge With Feet Elevated
Place the working heel on a low bench or step (30 to 45 centimetres). The elevated position increases the range of hip extension and the hamstring stretch at the bottom, creating a more demanding version.
How to do it:
- Lie on the back
- Place the working heel on a bench or step
- The leg should be nearly extended at the starting position
- The non-working leg is lifted and held in the bent or extended position
- Bridge from this elevated heel position
- Complete all reps on one side before switching
Sets and reps: 3 sets of 8 to 10 per side
Level 6: Single Leg Hamstring Bridge on Stability Ball
Place the working heel on a stability ball. The instability of the ball adds a continuous balance and hamstring co-contraction demand beyond the floor version.
How to do it:
- Lie on the back and place the working heel on a stability ball
- Lift the non-working leg off the ball
- Press through the working heel to lift the hips
- The ball’s instability requires continuous hamstring activation to prevent rolling
- Complete all reps on one side before switching
Sets and reps: 3 sets of 8 per side
Level 7: Nordic Hamstring Curl
The natural ultimate progression, developing the hamstrings eccentrically through a full range of knee flexion. As one of the most evidence-based hamstring injury prevention exercises available, the Nordic curl is the endpoint of the hamstring bridge progression series.
Clinical Applications
Hamstring Strain Rehabilitation
The single-leg hamstring bridge is the primary progression from the bilateral version in hamstring strain rehabilitation. As covered in the back of thigh pain article on this site, the progressive loading of the healing hamstring requires a staged approach.
Introduction criteria: Progress from bilateral to single-leg when the bilateral hamstring bridge can be completed for 3 sets of 15 with no pain and clear hamstring activation. Pain during the single-leg version should remain below 3 to 4 out of 10.
Asymmetry correction: The single-leg version directly addresses the side-to-side strength asymmetry that is both a consequence of hamstring injury (the injured side weaker) and a risk factor for re-injury. Giving the injured side an additional set per session until strength symmetry is restored is the most practical correction approach.
ACL Rehabilitation
The hamstring’s role in dynamic ACL protection through co-contraction makes hamstring strengthening a component of ACL rehabilitation at all stages. The single-leg hamstring bridge develops the unilateral hamstring strength that is specifically relevant to the single-leg loading of the ACL during walking, running, and athletic activity.
Running Injury Prevention
Research on hamstring injury in runners consistently identifies eccentric hamstring weakness and hamstring-to-quadriceps strength ratio imbalance as primary risk factors. The single-leg hamstring bridge, particularly with the slow eccentric and elevated foot progressions, directly addresses the eccentric hamstring weakness that predisposes to strain during the late swing phase of running.
Practical running programme inclusion: 3 sets of 10 per side twice per week, progressing to the slow eccentric and elevated versions over 6 to 8 weeks, as part of a comprehensive posterior chain programme alongside hip thrusts and single-leg RDLs.
Proximal Hamstring Tendinopathy
As covered in the hamstring bridge article on this site, progressive tendon loading through the hamstring bridge series is appropriate for proximal hamstring tendinopathy once acute sitting pain has settled. The single-leg version provides the increased loading needed as rehabilitation progresses beyond the initial stages.
Programming Guidance
As a posterior chain exercise in a general programme:
3 sets of 10 per side, 2 to 3 times per week. Progress through the levels as each becomes manageable.
As part of a hamstring injury prevention programme for runners:
- Bilateral hamstring bridge: 2 x 15 (warm-up activation)
- Single-leg hamstring bridge: 3 x 10 per side
- Single-leg RDL: 3 x 8 per leg
- Nordic hamstring curl (when ready): 3 x 6
Pairing with complementary exercises:
The single-leg hamstring bridge pairs naturally with single-leg glute bridge work for comprehensive unilateral posterior chain development:
- Single-leg hamstring bridge: 3 x 10 per side (hamstring emphasis)
- Single-leg glute bridge: 3 x 10 per side (glute maximus emphasis)
- Single-leg RDL: 3 x 8 per leg (posterior chain integration)
Asymmetry correction protocol:
When the weaker side shows more than 20 percent asymmetry compared to the stronger side (assessed by rep quality, hold time, or bridge height), give the weaker side one extra set per session until the asymmetry reduces to within 10 percent.
Frequently Asked Questions
How is the single leg hamstring bridge different from the single leg glute bridge?
The foot position is the primary difference. The single-leg glute bridge is performed with the working foot close to the hips, creating a near-vertical shin angle that maximises gluteus maximus activation. The single-leg hamstring bridge is performed with the working foot far from the hips, with the leg nearly extended, which shifts the primary load to the hamstrings. As covered in the single leg glute bridge exercise article on this site, these are complementary exercises that develop different aspects of the posterior chain rather than being interchangeable.
Why do my hamstrings cramp much more in the single-leg version than the bilateral?
The doubled demand of the single-leg version places approximately twice the load on the working hamstring compared to the bilateral version. This significantly increases the likelihood of cramping when first attempting the single-leg exercise, particularly if the bilateral version was already causing some cramping. The same resolution applies: progressive volume, post-exercise stretching, and adequate hydration. The cramping typically resolves faster for the single-leg version if the bilateral version has already been trained consistently.
Should I feel the single leg hamstring bridge in my glutes or hamstrings?
Primarily the hamstrings of the working leg, with some gluteus medius activation (felt in the outer hip as it maintains pelvic level). If the primary sensation is in the glutes rather than the hamstrings, the foot is too close to the hips. Move the working foot further away and use the heel-drive and hamstring pre-activation cues to shift the emphasis correctly.
How do I progress to the Nordic hamstring curl from the single leg hamstring bridge?
Build to 3 sets of 10 single-leg hamstring bridges with a 3 to 5 second hold and a 5 to 6 second eccentric lowering. Once this can be achieved with clear hamstring activation, level pelvis, and no cramping, introduce the Nordic curl at a low volume (3 sets of 3 to 4 reps) with a hands-catch at the bottom and build gradually. The Nordic curl is significantly more demanding than any bridge variation and requires a conservative introduction.
Can the single leg hamstring bridge replace the Nordic curl for hamstring injury prevention?
The single-leg hamstring bridge is an important component of hamstring injury prevention but does not fully replace the Nordic curl. Research on hamstring injury prevention specifically identifies eccentric hamstring strength at long muscle lengths as the primary protective quality, and the Nordic curl develops this quality more completely than the bridge series. The bridge series is the appropriate progression that leads to the Nordic curl rather than a permanent substitute for it.