Thoracolumbar junction mimicking quadriceps pathology

An elite rugby player, aged 24, presented with acute onset quadriceps ‘tightness’ after a high-intensity sprint session the previous afternoon. His main complaint was localised tenderness and ‘tightness’ in the right anterior thigh, mid-belly of rectus femoris. He first noticed the ‘tightness’ immediately after the sprint session, and it was particularly tender and stiff first thing that morning.

The patient denied any tearing or catching sensations in the quads while sprinting. It was his first sprint session in four weeks, and the previous day he had completed a weight-training session that included 3 sets x 5 reps of back squats with 150kg resistance: his heaviest weight-training session for six weeks. The patient also claimed the right-hand side of his lower back had felt tight after the weight-training.

Presentation

The athlete was able to perform a full squat pain-free and one-leg hopping was pain-free, although he was aware of tightness and a sensation in the right quads. Resisted hip flexion in sitting was unremarkable as was resisted knee extension in sitting at 90/45/0 degrees isometric knee extension. The right hemi-pelvis was anteriorly rotated and outflared, with increased tone in the right tensor fascia lata (TFL) and iliopsoas muscles. The sacrum was rotated left on left and L5 was also left rotated. The thoracolumbar junction was stiff to mobilise with increased tone through the right thoracolumbar erector spinae.

Hip flexion Thomas test with femoral nerve sensitisation was negative and neurological examination normal. Passive knee flexion whilst prone was decreased compared with the left side, with passive end range being slightly more restricted than the left side. In this position, active contraction of the quadriceps against resistance in full knee flexion was uncomfortable. The quadriceps demonstrated increased tone through the right rectus femoris, particularly mid belly.

Diagnosis

The athlete was deemed to be suffering acute onset quadriceps muscle tone/spasm after his sprint session, but without any local muscle tear or sprain. The athlete was advised of this and told that if he didn’t improve over the next 48 hours, MRI would be conducted to assess for local muscle damage/fibre disruption and fluid accumulation.

Factors likely to be involved in an acute onset spasm of the muscle include:

• High-intensity sprint session on a muscle that may have had pre-existing tonal changes from the heavy weight training. This may have pre-tensioned the rectus femoris, resulting in an increased resistance to stretch, especially from a position of full hip extension at the end of stance phase into hip flexion and leg recovery during the swing phase of sprinting.
• Of interest is the anteriorly rotated hemipelvis and stiff thoraco-lumbar junction, with increased tone through the right TFL, iliopsoas and paraspinals. This is a common pattern in quadriceps and groin injuries. The stiff thoraco-lumbar junction and hypertonic paraspinals is most likely a direct result of excessive compression loading with squats and use of the paraspinals to counteract the flexion force that heavy squatting imparts on the thoraco-lumbar spine.

Restricted hip extension may force the athlete to compensate with excessive and prolonged knee flexion in the transition from hip extension at terminal stance into hip and knee flexion with leg recovery in the swing phase. This may predispose the biarticular rectus to injury from excessive stretch and force production.

The neurological basis of this argument is that increased tone in the right iliopsoas will present the femoral nerve with an interface restriction as it passes through the psoas muscle as it exits the L2/3/4 nerve root levels. However, this athlete did not present with definitive signs of dysfunctional femoral nerve dynamics as assessed on a femoral nerve stretch.

Stiff thoraco-lumbar junctions are also common in athletes with anterior thigh symptoms. A facilitated segment found in the high- to mid-lumbar level may increase the excitability of the afferent nerve fibres belonging to the lumbar nerve roots, and cause the motor component of the femoral nerve to be hyper-excitable (similar to how an irritated L5/S1 segment may cause irritability of the sciatic nerve and lead to posterior thigh symptoms). The clinician must consider the close relationship between the high- to mid-lumbar nerve roots and the femoral nerve in anterior thigh symptoms.

Treatment

Initial treatment focused on trigger point releases and myofascial therapy to the rectus femoris muscle and the iliopsoas. This was performed to the point of discomfort (but not pain) with the knee relaxed in extension and also with the lower leg hanging over the edge of the plinth whilst supine to place the rectus in some stretch.

The athlete was also placed prone with the knee flexed to initial resistance (about 120 degrees flexion in this case). The patient passively held this position using a Mulligan strap, allowing the therapist to massage and trigger the right-sided paraspinals and mobilise the thoraco-lumbar junction.

On reassessment, the passive knee flexion in prone had improved to completely full range and pain-free at end range. Resisted knee extension in this full-flexion position was still uncomfortable. The athlete was instructed to apply heat to the anterior thigh (definitely no ice) at two-hourly intervals and not to stretch the quadriceps or hip flexors. He was shown how to self-trigger the paraspinals using a tennis ball, and the TFL using a golf ball.

The next day the athlete presented with passive prone knee flexion that was full range but still uncomfortable at end of range. The tenderness to palpation had reduced, but a slight increase in tone though the rectus was still evident. Treatment was continued directly to the quadriceps, TFL, psoas and thoracolumbar junction. The athlete was anxious to try some sub-maximal running but was discouraged. Running with increased quadriceps tone would almost definitely set back his recovery time; and even pool running or cycling tends to ‘re-tone’ the quads. The athlete was told to continue with the same self management as the previous night.

The next day he presented with full range and pain-free extension against resistance in knee flexion. The rectus was not tender and tone was normal. Treatment was carried out as the previous day, but the session ended with some assisted hip flexor stretches in a Thomas test position. Again, the athlete was instructed not to run that day.

On the next day, assessment findings were all normal. The athlete was allowed to complete a running session consisting of 12 x 60m run-throughs, building to full pace on the last 2 repetitions. This was completed with no ill effect. Re-assessment two hours after this session indicated that the quadriceps did not react with any increase in tone.

During the next four days, the athlete was allowed to train to full running acceleration, and then add in game specific skills. A heat-retaining thigh support was used during training until after the third running/ rehabilitation session. Kicking was the final activity to be undertaken that day.

The athlete played again incident-free within nine days of the injury.

Key points

• Thoracolumbar junction stiffness plays a role in anterior thigh symptoms that present as rectus femoris muscle pathology. Careful assessment is needed.
• Treatment of the thoracolumbar junction with the knee in passive knee flexion (presumably to elongate the femoral nerve and associated nerve roots) is effective in dealing with anterior thigh symptoms.
• Running and aggressive early rehab of quadriceps injuries almost always makes these conditions worse. Leave running until stretch and contraction are symptom free. An extra day or two before running may save you a week or two later if the athlete suffers a strain injury with a quadriceps that is still actively hypertonic. This is completely different to how hamstring injuries should be treated.
• Anterior thigh symptoms that are not strain-related will almost always tighten further if ice is applied. The clinician must make a judgement call to go with muscle pathology vs neural tone. Regular icing of a quadriceps injury without muscle pathology will almost certainly add a day or two before the muscle tone drops enough for functional rehab. MRI scanning will allow a definitive diagnosis but for the semi-professional and amateur, an extra day or two may be a better option than an expensive scan, so always trust your initial judgement and intuition on muscle strain vs muscle tone.
• If possible, always reassess muscle tone two to three hours after running. If the muscle is going to react, it will do so within this time, giving you a good measure of whether the rehab has been too aggressive.
• Any lower limb muscle injury will involve a pelvic component, whether poor local stabilisation or hypertonic muscle patterns around the pelvic muscles. Always consider what happens up north in the lumbo-pelvic region when deciding on rehab and treatment options.

Chris Mallac