In previous issues of SIB I presented management ideas for soft-tissue injuries involving the hamstrings and groin (adductors). This article will focus on the last of the major muscle groups in the thigh to suffer a similar injury fate â€“ the quadriceps.
Injury to the quadriceps almost always involves the long cylindrical and bipennate quadricep â€“ the rectus femoris. Tears and strains of the vastus lateralis/medialis/intermedius are relatively uncommon, except when preceded by an unresolved intramuscular haematoma (cork or dead leg). Whereas hamstring and adductor muscle injuries can very often be difficult to manage due to the multifactorial nature of the causative elements, luckily rectus injuries are more straightforward in terms of rehabilitation. However, some unique aspects of their management will be highlighted in this article.
The long cylindrical rectus femoris muscle is almost exclusively involved in muscle strain pathologies involving the quadriceps, principally because of its two joint function. It is the most superficial and anterior of all the quadriceps muscles. It originates from the AIIS and a reflected head blending with the anterior hip joint capsule and iliofemoral ligament. The two heads form a thick fascial aponeurosis that then blends into the rectus femoris muscle tissue. Tears in the rectus usually involve the proximal and middle third of the muscle.
The rectus femoris works to extend the knee along with the other quadriceps. As it crosses the hip joint, it also works synergistically with the other hip flexors to generate hip flexion torque, and also works to stabilise the pelvis upon the weight-bearing femur.
The other relevant structure is the femoral nerve which courses down from the deep portion of the lumbar plexus into the anterior femoral triangle and down the anterior thigh. The femoral nerve may have an important pathomechanical implication in rectus femoris pathology in the same way as the sciatic nerve may be involved in hamstring pathology.
Possible pathologies contributing to rectus pathology or mimicking rectus pathology include lumbar spine referral and femoral nerve (L2,3,4) irritation, psoas and iliacus pathology and trigger points, anterior hip joint pathology including acetabular labral tears, psoas bursa pathology and long standing/persistent deep quadriceps haematoma and subsequent myositis ossificans.
The rectus femoris is mostly commonly injured in the acceleration phase of sprinting, explosive jumping (eg, long jump), kicking (especially long kicking), or when contracting and meeting a resistance (such as two players kicking a ball at the same time). Unlike other muscle pathologies such as the hamstrings, it is possible for an athlete to 'mask' a rectus femoris injury. Minor grade tears/strains tend only to become functionally limiting when at close to top-end speed sprinting (implications of this will be highlighted in rehabilitation) and when attempting to kick on the run or to kick for distance. Any activity below this, and athletes may be able to continue to compete.
The athlete will usually remember the specific incident because it usually involves explosive muscle contraction, and all grades of strain are initially functionally limiting while attempting to perform maximal speed efforts or generate force with kicking. The athlete may be able to continue playing/training usually at submaximal speed. The injury will most definitely be more noticeable following cooling down.
Grade 1 strains will have local tenderness along part of the rectus femoris, with associated (and easy to palpate) muscle spasm above and below the injury site. Pain will be present on both knee extension (especially in positions of hip extension) and hip flexion strength testing, and on passive prone knee bend and possibly hip extension stretching. Grade 2 strains present with similar yet much more significant findings. Grade 3 tears will usually have an observable and very palpable defect in the muscle, with 'bunching' of the muscle with contraction. This, however, will become hidden under the subsequent haematoma. The 'bunching' of the muscle which will be present after resolution of symptoms will rarely cause any functional deficits.
It is important to highlight other associated factors that possibly may be involved in rectus pathology, or hinder the rehabilitation of a rectus injury. First and foremost is psoas and iliacus spasm/trigger points. This may contribute to problems in two possible ways. Firstly, an acutely hypertonic iliopsoas in spasm will cause local weakness of hip flexion and restriction to movement into hip extension. The rectus may be required to compensate by generating more force to assist in hip flexion, and as a result may fatigue and overload earlier than it should. Furthermore, a psoas in spasm may restrict lumbar spine extension, resulting in a compensatory increase in hip extension, potentially overloading the rectus.
Secondly, the femoral nerve has its originating cords passing directly through the psoas muscle. A restricted psoas in spasm may generate a mechanical interface problem with the femoral nerve. The knock-on effect may be reflected further down the neurodynamic chain. A psoas may become acutely hypertonic in the presence of a lumbar spine pathology (discal and sponylolisthesis in particular), overuse in hip flexion or as a compensatory lumbar spine stabiliser in the presence of a poorly functioning transversus abdominus.
The femoral nerve has also been implicated in rectus femoris injuries, in a similar way that the sciatic nerve is implicated in hamstring strains. The femoral nerve may be assessed using a modified Thomas test position incorporating thoracic spine and cervical spine flexion, with a sensitising movement of head flexion and extension to elicit symptoms in the anterior thigh. This may be very difficult to assess in an acutely injured rectus femoris.
Of further interest is the role the thoracolumbar junction plays in rectus pathology. Clinically, it has been found that difficult rectus pathologies may have an associated movement block in the T12/L1 region. These respond well to joint mobilisations with the rectus on gentle stretch (to the point of R1).
The standard elevation, compression and incorporating gentle active or passive knee flexion and extension while being iced (cryokinetics). This is best performed in side lying with a strap tied around the foot and passed over the shoulder. Gentle oscillating flexion and extension may be performed in this position, as it allows the hip to stay in relative extension. As mentioned in previous issues on the management of soft tissue lesions, the continual movement will help avoid 'ice scarring' of the torn rectus to the thick 'fascia lata' that surrounds the anterior thigh musculature.
Similar to other muscle injuries, soft tissue therapy can start almost immediately to the tissues above and below the injury site to minimise associated reactive spasm that may hinder healing of the injury.
Dealing with any associated kinetic chain deficits can also begin at this stage, such as soft tissue releases of psoas and iliacus, deep abdominal muscle stabilisation if appropriate, mobilisation and soft tissue management of restricted hip joints/lumbar spine/sacroiliac joints, in particular the thoracolumbar junction.
Rehabilitation of rectus femoris injuries will be highly dependent on the initial grade of the injury, and the sport the athlete participates in. Rehabilitation of soccer and Australian Rules footballers will take longer than non-kicking rugby union/league players, basketballers and hockey players. Credit for some of the following ideas must be given to Peter Stanton and Victor Popov, physiotherapists with the Brisbane Lions AFL team in Australia. They have modified some of the traditional ideas on rehabilitation of quadriceps injuries when dealing with elite level AFL players in order to have them back to full competition in the shortest time possible.
In previous articles in this series, I highlighted the aggressive accelerated rehabilitation of hamstring injuries through use of 'rehab running'. Rehab running for rectus injuries differs from hamstrings in a number of key areas. These are outlined as follows:
1.Don't start too soon. Rectus injuries tend to do poorly if running is started too early. Delay running until quads stretch and contraction (both knee extension and hip flexion) is normal. This differs from hamstrings, whereby running is encouraged early in the rehabilitation process to accelerate the recovery process.
The most important element of this running is to educate the athlete to run BELOW the point of pain and/or restriction. As long as the quadriceps feel good, the speed can be increased. The key difference with rehab running the quads as opposed to the hamstrings is the danger of re-injury at close to top-end speed. Athletes generally have a better appreciation of small percentage increases in speed with hamstrings. This awareness is not so acute with quads. That is, the athlete's perception of the difference between 90% speed versus 95% may be way off. This has important clinical implications when the athlete tells you he/she can run 100% speed pain-free.
2. Don't run everyday, only every other day. Again, rectus injuries tend to do poorly if overworked day after day. Leave running for every second day, manage the 'tone' the next day and cross train. Overzealous rehabilitation every day will delay the recovery process.
3. Limit distances. Whereas hamstring injuries like longer running distances of 90 to 120 metres with an extended acceleration phase, rectus injuries respond better to short distances of 60 metres. A typical rehab running programme may be 12 x 60 metres with a 20 metre acceleration, 20 metre cruise phase and 20 metre deceleration.
4. Run before you can kick. If the athlete you deal with is involved in a kicking sport (soccer and AFL), you want them fully running (sprinting) prior to kicking. Commence with short-distance kicks before progressing to long-distance kicks.
5. Gradual re-introduction of skills. A typical rehab session may involve 12 x 60 metre run throughs (as described earlier), followed by gradually increasing times of skills component to add in the element of fatigue and sport-specific conditioning. Again, leave kicking components to the very end.
6. Cross-training. As it is ideal to delay running of quadriceps injuries, the athlete will lose conditioning relatively quickly if cross-training for cardiovascular fitness is not considered. Be careful with long kick sessions in the pool in the early part of the rehabilitation, as this will load the quads and increase tone, making it difficult to manage tone during treatment. Swimming with a pool buoy between the legs and stationary bike represent the two safest modalities for cross training.
As with hamstring injuries, it is ideal for quad injuries to be training fully and running flat out 48 hours (24 hours if taking risks) prior to competition. The most significant limiting factor with quadriceps injuries is acceleration and kicking. Fatigue does not play a significant role with these injuries as they do with hamstrings. Therefore, volume of work in a session is not as critical a factor as intensity when fitness testing. The athlete needs to be flat out sprinting (full acceleration) repeatedly for around 10-12 x 60 metres and follow this with a solid kicking session. Reassess stretch, strength and muscle tone the next day and decide based on a 24 hour reaction to training.