Pelvic instability

What does pelvic instability mean?

The pelvis forms a closed ring with the sacrum, ilium and the pubic symphysis. Stability arises from passive positive fit (bones, ligaments) and active muscular guidance (torso, pelvic floor and hip muscles). If this system becomes unbalanced, it is called instability. This can be mechanical (e.g. after fractures) or functional (e.g. muscular insufficiency, hormonally induced ligament laxity).

• Common pain locations: buttocks/SIJ, side hip, groin, pubic bone, inner thigh
• Typical: stress-dependent pain, pain when turning over in bed, getting up, climbing stairs
• Special form: pregnancy-related pelvic girdle pain (loosening of the symphysis)

Anatomy and biomechanics of the pelvic girdle

The pelvic ring consists of two sacroiliac joints (connection of the sacrum and ilium) and the anterior pubic symphysis. Strong ligament structures stabilize while joint play is minimal. The core muscles (deep abdominal muscles, multifidi), hip muscles (gluteal muscles) and the pelvic floor ensure active stabilization. A finely tuned interaction prevents shearing forces and ensures pain-free walking, running and rotation.

• Passive stability: positive fit, ligaments (anterior/posterior sacroiliac ligament, iliolumbar ligament), joint capsules
• Active stability: deep trunk tension, pelvic floor co-activation, gluteus medius/minimus
• Load paths: Forces run through the SIJ and symphysis pubis - disruptions lead to overloading of adjacent structures

Symptoms: How do you recognize pelvic instability?

• Stabbing or dull pain in the buttocks/lower back, often on one side over the sacroiliac joint
• Anterior groin pain or pressure pain on the pubic bone (symphysis pubis)
• Pain when walking, standing for long periods, turning over in bed, standing on one leg, climbing stairs
• Feeling of “folding away” or lack of control in the pelvis/hip area
• Radiating into the inside of the thigh, less often into the knee
• Increased after exertion, improves at rest; Morning start-up pain possible

Causes and risk factors

• Functional instability: muscular insufficiency of the trunk and gluteal muscles, pelvic floor imbalance
• Hormonal ligament laxity: especially during pregnancy and breastfeeding
• Sports overload: change of direction/impact sports (football, hockey), running volumes
• Morphological factors: leg length discrepancy, misalignment of femur/pelvis, hyperlaxity
• Post-traumatic: after pelvic ring fractures or operations; rarely nonunions
• Concomitant diseases: osteitis pubis, stress fractures, spondyloarthritis

Diagnostics: This is how we proceed

The diagnosis is based on a careful history, targeted clinical tests and – if necessary – imaging procedures. Radiation-free procedures and clinical functional diagnostics are at the beginning.

It is important to differentiate from hip joint pathologies, lumbar nerve root irritations as well as stress fractures and osteitis pubis.

Conservative therapy – the central pillar

The goal is to restore active stability and control pain without unnecessary immobilization. The therapy plan is built up gradually and adapted to the individual.

• Education & activity advice: Control stress, use pain-free freedom of movement
• Physiotherapy with a focus on stability: training the deep trunk (transversus, multifidi), gluteal muscles, hip external rotators
• Pelvic floor training: coordinated control with trunk tension
• Motor control: transitions (sitting-standing), one-legged stance, walking and running technique
• Manual therapy: soft tissue techniques close to the joints, mobilization in low-pain areas
• Aids: Pelvic or SI belt for a limited time to provide everyday relief
• Pain therapy: local measures (warm/cold), topical NSAIDs, oral low doses for a limited time
• Tape/Bracing: for short-term proprioception and load reduction
• Return-to-activity concept: gradual increase in workload with objective criteria

If you are overloaded with sport, training plans are adjusted. During pregnancy/breastfeeding, the anterior pelvic structures are particularly protected with everyday tips (e.g. pelvis in neutral position, symmetrical loading, small steps when turning over).

Targeted injections and minimally invasive procedures

If conservative measures are not effective enough, targeted injections can help confirm the diagnosis and temporarily reduce pain. The indication is cautious and after informed consent.

• SIJ/symphysis infiltration under imaging: local anesthetic, if necessary with low-dose cortisone for short-term inflammation reduction
• Trigger point/tendon insertion treatment of accompanying myofascial symptoms
• Radiofrequency therapies on the SI joint: in selected, chronic cases for pain modulation

Regenerative procedures (e.g. PRP) can be discussed in the area for tendon insertion problems; Evidence for true “ligament stabilization” of the pelvis is limited. Such procedures are only used - if at all - after careful examination, information and outside of standard care.

Surgical options – rarely required

Operations are exceptional indications in the case of clearly proven mechanical instability, persistent severe pain and failure of consistent conservative therapy.

• SIJ fusion/stabilization: in cases of severe instability or degenerative SIJ pathology
• Symphysiodesis/plate osteosynthesis: in rare cases with anterior instability
• Reconstruction after pelvic ring fractures, treatment of nonunions

The decision and procedure are based on imaging, clinical findings and functional goals. We provide neutral advice and refer you to designated centers if surgery is indicated.

Rehabilitation and everyday life – this is how stabilization works

• Low-pain practice with a high number of repetitions, focus on quality instead of quantity
• Progression: from isometric tension to functional chains (squats, hip hinge, step-ups)
• Integration into everyday movements: lifting with core tension, symmetrical carrying, break management
• Only start running and jumping after stable single-leg loading without any discomfort
• Monitoring: pain scale (0-10), stress diary, adjustments every 2-4 weeks

Forecast: What are the prospects?

Many functional pelvic instabilities improve significantly with targeted exercise treatment, load management and temporary support (belt/tape). Postpartum discomfort often resolves within months but requires structured pelvic floor and stability training. Protracted courses are possible, especially if there is no recognized accompanying pathology or inadequate muscular control.

• Favorable: early functional diagnostics, good training adherence, realistic load control
• Unfavorable: severe ligament injuries, uncorrected misalignments, chronic overload

Prevention and self-management

• Regular training of the core, pelvic floor and gluteal muscles
• Plan to gradually increase training volumes in sports with changes in direction
• Check leg length differences and foot/leg axes and, if relevant, compensate
• Workplace ergonomics, breaks with short activation exercises
• After pregnancy, early, guided regression and gradual increase in load

When should you seek medical advice?

• Persistent pain for several weeks despite rest/exercises
• Sudden severe pain following trauma
• Fever, severe night pain or pain at rest
• Neurological deficits, sensory disorders, bladder/rectal problems
• Pain during pregnancy/breastfeeding with significant interference with everyday life

Special features during pregnancy and breastfeeding

Hormonal changes loosen ligament structures to make birth easier. This can temporarily reduce the stability of the symphysis and SIJ. The aim is to provide practical everyday relief and gentle stabilization.

• Tips: small steps, standing up symmetrically, avoiding crossing your legs
• Lap belt according to instructions: only use temporarily and in specific situations
• Gentle exercises with a focus on breathing, pelvic floor co-activation and posture
• Drug pain therapy only after medical consultation

Sports and return-to-play

For physically active patients, load control is planned individually. A structured step model reduces relapses and enables a safe return.

Differential diagnoses at a glance

• Osteitis pubis (inflammatory overload of the pubic symphysis)
• Stress fractures of the pelvis/hip
• Hip joint pathologies (labrum, femoroacetabular impingement)
• Lumbar facet/nerve root irritation
• Sacroiliac joint osteoarthritis
• Inflammatory rheumatic diseases (e.g. spondyloarthritis)

Your visit to us in Hamburg

Our orthopedic practice is located at Dorotheenstraße 48, 22301 Hamburg. We plan diagnostics and therapy transparently and step by step - conservatively, function-oriented and without unnecessary interventions.