At Thrive Body Clinic, one of the most common concerns we hear from gym-goers is: “My back felt fine while I was lifting, but it really hurt later on.” If you’ve ever walked out of the gym feeling accomplished after a heavy squat or deadlift session, only to find your low back or sacroiliac joint (SIJ) aching hours later, you’re not alone. This delayed discomfort can be frustrating, especially when the lift itself felt smooth and pain-free.

In this article, we’ll explore why this happens, what role the sacroiliac joint and lower back play in lifting, and how osteopathy can help you manage, recover from, and prevent these issues.

The Role of the Low Back and SIJ in Lifting

Deadlifts and squats are compound movements that engage multiple joints and muscle groups. While the prime movers are usually the glutes, hamstrings, quadriceps, and spinal erectors, the sacroiliac joint and lower back act as crucial stabilisers.

• The sacroiliac joint (SIJ): Located where the spine meets the pelvis, this joint has limited movement but plays a vital role in transferring forces between the upper and lower body.
• The lumbar spine (low back): These vertebrae act as a bridge between the pelvis and the thoracic spine, providing both mobility and stability.

When you squat or deadlift, your SIJ and lumbar spine don’t just “support” the movement – they absorb and distribute force. If these forces aren’t managed well, strain can build up without you realising it in the moment.

Why It Hurts Afterwards (and Not During)

It can seem strange that the pain only appears hours later or the next day. Here are some of the most common reasons:

1. Delayed-Onset Strain

Lifting often creates micro-strains in the muscles, ligaments, and joints. While adrenaline and focus may keep you comfortable during the session, inflammation and stiffness set in later. This is why many people feel soreness or pain after sleeping or sitting following a heavy lifting session.

2. Muscle Fatigue and Compensation

As your glutes, hamstrings, or core muscles tire, the stabilising load shifts towards the lower back and SIJ. You may not notice this shift while lifting, but fatigue can cause small changes in your form, such as rounding your lower back or letting your hips tilt. These subtle changes increase stress on the SIJ and lumbar spine.

3. Accumulated Load Rather Than a Single Lift

Pain isn’t always about a single “bad rep.” It often comes from the cumulative effect of load, repetition, and fatigue. Even with good form, multiple sets of squats or deadlifts can add up, leaving the low back and SIJ irritated afterwards.

4. Joint Irritation Takes Time to Develop

Unlike a muscle cramp that appears instantly, joint irritation often develops more slowly. The sacroiliac joint, in particular, can feel fine during activity but become irritated once you’ve cooled down, sat in the car, or gone to bed.

5. Tight or Imbalanced Muscles

If certain muscles – such as the hip flexors, hamstrings, or glutes – are tight or weak, the SIJ and low back may take on more stress than they should. For example, if the glutes aren’t firing well during a deadlift, the lumbar spine might overwork to compensate.

Is It an Injury or Just Post-Training Discomfort?

Not all post-lifting discomfort signals injury. Distinguishing between normal post-exercise soreness and problematic pain is key:

• Normal: Muscle soreness, mild stiffness, easing with gentle movement.
• Potential issue: Sharp pain, localised ache at the SIJ or spine, pain that worsens rather than improves over a few days, or discomfort interfering with daily activities.

If you’re unsure, it’s always better to get checked by a professional.

How Osteopathy Can Help

At Thrive Body Clinic, we take a holistic approach to back and SIJ pain related to lifting. Here’s how osteopathy can support you:

1. Assessment of Movement Patterns

We look beyond the painful area, checking how your hips, spine, and pelvis work together. Subtle restrictions in one joint often force others to compensate, which can overload the SIJ and low back.

2. Hands-On Treatment

Osteopathic techniques such as joint articulation, soft tissue release, and gentle adjustments can help ease stiffness, reduce inflammation, and restore mobility in the affected areas.

3. Strengthening and Stability Advice

We’ll guide you in improving the balance between key muscle groups. Often, strengthening the glutes, core, and deep stabilisers helps take pressure off the SIJ and lower back.

4. Load Management Strategies

We work with you to adapt your training – adjusting volume, intensity, or technique to allow your body to recover while still progressing. Sometimes small tweaks, like stance width or bar placement, make a big difference.

5. Prevention Through Body Awareness

Osteopathy helps improve awareness of how your body moves and reacts to stress. By understanding your unique biomechanics, you’ll be better equipped to prevent problems from returning.

Tips for Lifters to Protect the Low Back and SIJ

If you love deadlifting and squatting (and many of our patients do!), here are some practical ways to reduce the risk of post-session discomfort:

• Warm up properly: Don’t skip mobility drills for the hips, spine, and hamstrings.
• Engage your core: Think of bracing, not just tensing, to support your spine.
• Don’t train to exhaustion every session: Fatigue increases the risk of form breakdown.
• Check your recovery: Sleep, hydration, and stretching all influence how your joints respond after lifting.
• Listen to your body: If pain lingers or worsens, seek professional help sooner rather than later.

Final Thoughts

Low back or sacroiliac joint pain after squats and deadlifts is a common issue, but it’s not something you have to live with. Often, it’s a sign that your body is asking for better balance, recovery, or support.

At Thrive Body Clinic, we help lifters not just recover from pain but also build resilience so they can keep training with confidence. If you’ve noticed discomfort after your workouts, even if the lifts themselves feel fine, don’t ignore it – a little attention now can save you from bigger setbacks later.