RSM-DPA-006
Written by Hironori Ikeda, MSc Sports Medicine
RSM International Academy · Chiang Mai, Thailand
Why Does the Knee or Pelvis Shift During a Lunge?
A front knee can drift as the foot accepts weight, while the pelvis may turn only when the rear hip reaches extension. Calling both a weak-hip problem misses the difference between the two legs.
At RSM, I first separate step length from stance width and identify the troublesome phase. I then compare front-ankle travel, rear-hip position and trunk inclination while keeping the original task clear.
This guide connects those comparisons to quadriceps, gluteal, calf and hip-flexor function. You will learn when a setup change is useful, when a local contact has a reason and how to avoid mistaking an easier lunge for a restored original task.
In This Article
- Why Does the Knee or Pelvis Shift During a Lunge?
- In This Article
- 1. Define the Lunge: Foot Placement Comes Before Interpretation
- 2. Front-Leg Loading and Rear-Hip Length: Different Anatomical Questions
- 3. Front Ankle or Rear Hip: Which Finding Matches the Shift?
- 4. Trunk and Base of Support: Test One Hypothesis
- 5. Re-Test the Same Lunge, Then Decide What Still Needs Work
- Related RSM Clinical Blogs
- Study Dynamic Posture Assessment at RSM
1. Define the Lunge: Foot Placement Comes Before Interpretation
Identify whether the client steps forward and returns, lowers between fixed feet, or lunges sideways. Start with the version that causes difficulty and record the lead leg. Observe whether the front knee drifts during weight acceptance, the pelvis rotates near the bottom, or the shift begins when pushing back.
Mark the front-to-back distance and the side-to-side spacing of the feet. These are different variables: a long step can still have a narrow base. Keep the usual foot angle, depth and pace visible rather than instructing a new technique before seeing the baseline.
Riemann and colleagues found different joint demands with lunge direction and step length in healthy young adults. I therefore treat setup as part of the assessment. If a painful or unstable knee cannot safely accept the step, choose appropriate assessment rather than asking for more repetitions.
2. Front-Leg Loading and Rear-Hip Length: Different Anatomical Questions
The front hip and knee flex as the body lowers. Quadriceps at the anterior thigh transmit extension force through the patella to the tibial tuberosity, while gluteus maximus behind the hip contributes hip extension. Their force helps control lowering and return the person upward.
At the rear leg, iliopsoas crosses the front of the hip to the lesser trochanter and flexes the hip. Rectus femoris crosses both hip and knee, contributing to hip flexion and knee extension. Rear hip extension combined with knee flexion changes its length demand; anterior-thigh tension is therefore not automatically an iliopsoas finding.
If the front calf is the relevant complaint, support the leg and compare tolerable contact in superficial gastrocnemius with the deeper soleus region. Soleus reaches the heel through the Achilles and opposes forward tibial advance. I do not choose deep anterior-hip pressure simply because the rear leg feels tight.
3. Front Ankle or Rear Hip: Which Finding Matches the Shift?
If the front heel lifts early or knee travel appears limited, compare knee-to-wall dorsiflexion with the heel down. Keep foot direction and the measurement method consistent. Note the range and whether the client reports calf tension, an ankle pinch or no familiar symptom.
If the pelvis turns as the rear thigh moves behind the body, compare a comfortable supported split stance. Watch hip extension relative to the pelvis rather than counting lumbar arching as hip range. A shorter split is a separate trial; it does not prove a hip-flexor release.
The ankle test has evidence for repeatable measurement, but a small side difference does not locate a shortened muscle. I keep the regional result only when it helps explain the original lunge. Persistent groin pain, spreading tingling or progressive weakness calls for broader assessment rather than stronger stretching.
4. Trunk and Base of Support: Test One Hypothesis
For a balance-related wobble, I may first widen the side-to-side foot spacing slightly while keeping step length similar. Compare the same lowering phase. Light fingertip support is another separate option; improvement with support does not demonstrate stronger hip muscles.
If trunk inclination is the question, compare a comfortable forward lean with the original trunk position without forcing lumbar extension. Farrokhi and colleagues found greater hip-extensor demand with a forward trunk in the lead leg. Leaning forward is therefore a different loading choice, not automatically an error.
Keep the option that improves the relevant symptom or control without creating pain elsewhere. A repeatable local muscle finding may justify brief, supported contact, but it must earn its place in this comparison. If a setup change already solves the immediate task problem, more pressure is not required to explain the result.
5. Re-Test the Same Lunge, Then Decide What Still Needs Work
Return to the original lead leg, step length, side-to-side spacing, foot direction, depth and pace. Repeat the familiar symptom-producing phase if it remains tolerable. Note pain, confidence and whether the knee or pelvis changes before, at or after the same point.
A loaded split-squat study found that step length changed joint motion and muscle activation. Its fixed-foot exercise is not identical to a stepping lunge, but it reinforces why changing the setup changes the question. Do not attribute an easier shortened step to manual treatment.
If the task only improves with a useful adaptation, document that option and plan appropriate practice or loading. If the original problem persists, reconsider joint, muscular and balance factors. Marked swelling, locking, inability to bear weight or recurrent giving way needs clinical assessment; one comfortable lunge does not establish readiness for repeated sports efforts.
Related RSM Clinical Blogs
Browse all Dynamic Posture Assessment clinical guides
▷ Squat Shifts to One Side: Foot Pressure, Hip & Trunk — Dynamic Posture Assessment · Compare the split stance with a squat where both legs share the same task.
▷ Knee Falls In on Squat or Landing: Hip, Foot & Trunk — Dynamic Posture Assessment · Examine an inward front-knee path without reducing it to isolated gluteal weakness.
▷ Lunge With Pelvic or Knee Shift: Hip, Ankle & Control — Deep Tissue Massage · Translate matching lunge findings into supported calf, hip or medial-thigh contact choices.
Study Dynamic Posture Assessment at RSM
In Dynamic Posture Assessment & Kinetic Chain Training, practise comparing front-leg loading, rear-hip position and trunk strategy with a clear re-test. Completion of Trigger Point Therapy supplies a clinical palpation foundation.
Deep Tissue Massage develops how to choose a muscle layer and supported contact when local findings agree with the lunge. Sports Massage extends the comparison to repeated training demands, also building on TPT.
View the course schedule and entry requirements · Ask about course suitability and registration
About the Author
Hironori Ikeda, MSc Sports Medicine
Hironori leads RSM International Academy in Chiang Mai, Thailand. His teaching connects functional anatomy, clinical palpation and kinetic-chain assessment with practical massage decisions.
Read Hironori’s professional background and teaching approach