Original Editors - Pieter Jacobs
Lumbar strain is a commonly wielded diagnosis (Depalma 2011, Houglum 2001) for mechanical low back pain but is without anatomical or histologic evidence.(Depalma 2011) Much of the knowledge of lumbar strain is extrapolated from peripheral muscle strains. (Depalma 2011)
In strains, the muscle is subjected to an excessive tensile force leading to the overstraining of the myofibres and, consequently, to their rupture near the myotendinous junction. (Jarvinen 2007, Depalma 2011)
The current classification of muscle injuries identifies mild, moderate and severe injuries based on the clinical impairment they bring about. (Jarvinen 2007)
Clinically Relevant Anatomy
The lumbar spine consists of 5 moveable vertebrae numbered L1-L5. The complex anatomy of the lumbar spine is a remarkable combination of these strong vertebrae, multiple bony elements linked by joint capsules, and flexible ligaments/tendons, large muscles, and highly sensitive nerves. It also has a complicated innervation and vascular supply.
The lumbar spine is designed to be incredibly strong, protecting the highly sensitive spinal cord and spinal nerve roots. At the same time, it is highly flexible, providing for mobility in many different planes including flexion, extension, side bending, and rotation. [level of evidence: 5]  [level of evidence: 2C]
Lumbar strain can origine in the following muscles (Houglum 2001, Putz 1997, Meeusen1 2001): M. erector spinae (M. iliocostales, M longissimus, M. spinalis) M semispinales, Mm multifidi, Mm rotatores M. quadratus lumborum M. serratus posterior.
Strains are defined as tears (partial or complete) of the muscle-tendon unit. Muscle strains and tears most frequently result from a violent muscular contraction during an excessively forceful muscular stretch. Any posterior spinal muscle and its associated tendon can be involved, although the most susceptible muscles are those that span several joints.You can define acute and chronic lumbar strain. Acute pain is most intense 24 to 48 hours after injury. Chronic strains are characterized by continued pain attributable to muscle injury.  [level of evidence: 2C]
Low back pain is the second most common symptom that causes patients to seek medical attention in the outpatient setting. Approximately 70% of adults have an episode of LBP as a result of work or play.
Exact numbers regarding the international frequency of low back injuries are not known. Studies done in The United States have shown that 7-13% of all sports injuries in intercollegiate athletes are low back injuries. The most common back injuries are muscle strains (60%) and
disc injuries (7%). Athletes are more likely to sustain injuries in practice (80%) than during competition (6%). American football (17%) and gymnastics (11%) are reported to have the highest rates of low back injury. [ level of evidence: 2C]
A recent French study reported over 50% of French individuals aged 30-64 years had experienced at least 1 day of LBP over the previous 12 months. 17% had suffered LBP for more than 30 days in the same 12-month period. [level of evidence 3]. The authors noted that the prevalence of LBP varied between men and women. There was an increased incidence with increasing age for LBP that lasted more than 30 days . These data were similar to those of other countries.
In an African study, the mean LBP point prevalence among adults was 32%, with an average 1-year prevalence of 50% and an average life-time prevalence of 62%  [level of evidence: 1A]
Common symptoms include pain (1)(level of evidence 5). This pain is a diffuse pain in the lumbar muscles, with some radiation to the buttocks.(4) (level of evidence 2A)The pain could be exacerbated during standing and twisting motions. With active contractions and passive stretching of the involved muscle the pain will increase. (2) (level of evidence 5)
Other symptoms are point tenderness, musle spasm, possible swelling in and around the involved musculature, a possible lateral deviation in the spine with severe spasm, and a decreased range of motion. (3)(level of evidence:2A)
- localized lumbar pain
- diffuse pain in lumber muscles
- Osteoporotic compression fracture  (Level of Evidence: 2C)
- spine tenderness
- may have weak/asymmetric reflexes
- decreased in extension
- exaggerating lumbar lordosis
- palpable ‘step-off’
- tight hamstings
No abnormalities.  (Level of evidence: 3B)
Imaging is not indicates unless there are:
- any red flag signs
- any radicular or abnormal neurological clinical features
- or if the symptoms have persisted for more than a month.
In these cases, it is important to exclude other differential diagnosis, by using X-rays or MRI. (Level of evidence: 5)
The physical examination contents:
•Inspection (level of evidence:5) (level of evidence:5)
-Inspect the spine for abnormal curvatures (f.e. scoliosis) -Erythema -Observe the gait (posture and movement)let the patient walk across the room, turn around and let him come back. -Observe the seated position of the patient abnormal posture caused by pain and muscle spasm
•Palpation --> Point tenderness
-Bony tissue -Soft tissue
-flexion of the back -Signs of limited range of motion or a decreased lumbar lordosis are important but most of the low back pain patients show this symptoms.
-Neurovascular assessment (L4-S1) °Test heel and toe walking °Positive test: marked asymmetry
•SLR± ankle dorsiflexion
-Positive test: radiated pain into calf
-Pain in the affected limb, when testing the unaffected limb
•SLR + Lasègue
-SLR until pain, then flex the knee. -Positive test: reduces pain when nerve is irritated
-Flexion ABduction External Rotation of the hip -Pain when SI-pathology
•One leg extension test
-standing on 1 leg with the back in extension -pain can indicate spondylolysis
•Leg length evaluation
-Measure from ASIS to medial malleolus (cm)
The neurological tests are mostly negative and a lumbar strain is not accompanied by paresthesias or weakness in the legs or feet. Patients with lumbar spine are tender to palpation in the lower back. Other physical findings are loss of normal lumbar lordosis and spasm of the paraspinal muscles. The SLR’s may cause pain in the lower back just like other tests that cause spinal motion. Often there’s an antalgic posture.
- Non-steroidal anti-inflammatory drugs (NSAIDs) are recommended in the acute phase to help reduce the swelling and inflammation.(level of evidence:1A)
- Diclofenac (voltaren) - Ibuprofen(ibuprin,advil,motrin). - Cox-2 selective NSAID’s ( less effects on the gastrointestinal tract)
- Muscle relaxants can also be prescribed to treat muscle spasms and facilitate light physical therapy. 1A)
- No studies support the use of oral steroids in patients with acute low back pain.  (level of evidence 2A)
Physical Therapy Management
In the acute phase of a lumbar strain Cold therapy should be applied (for a short period up to 48 h)to the affected area to limit the localized tissue inflammation and edema. (level of evidence 2A) (level of evidence:1A) Recent studies have found that continuing ordinary activities within the limits permitted by the pain leads to more rapid recovery than bedrest. (level of evidence 1B) TENS and ultrasound are often used to help control pain and decrease muscle spasm ( level of evidence:5)
The resulting pain and muscle spasm from acute strains must first be resolved with modalities(ice, TENS, ultrasound), mild stretching exercises along with limited activity.
A few stretching exercises: (level of evidence: 5)
- Single en double knee to chest.
Lie down on your back with your knees bent and your heels on the floor. Pull your knee or knees as close as you can to your chest, and hold the pose for 10 seconds. Repeat this 3 to 5 times.
- Back stretch
Lie on your back, hands above your head. Bend your knees and , keeping your feet on the floor, roll your knees to onse side, slowly. Stay at one side for 10 seconds repeat 3 to 5 times.
- 3. Press up.
Begin by laying flat on the ground (face down). When doing this exercise it is important to keep the hips and legs relaxed and in contact with the floor. Keep your hands in line with your shoulders. Inhale, then exhale and press up using the hands keeping the lower half of your body relaxed. Hold until you need to inhale, then move down, lay flat on the ground to rest, and repeat ten times.
- Kneeling lung (stretching iliopsoas)
- stretching piriformis
- stretching quadratus lumborum
There is insufficient evidence to make a reliable recommendation regarding massage for acute low back pain. There is limited evidence about the use of acupuncture in the treatment of acute low back pain. (level of evidence 2A)
progression of strengthening exercises should begin once the pain and spasm are under control. The muscles requiring the most emphasis are the abdominals, especially the obliques, the trunk extensors and the gluteals. Placing all of the emphasis in the rehabilitation specifically on the injured muscle is not beneficial.
As with all spinal injuries, posture and body mechanics should be assessed and corrected as needed.Training the core stability is an important part in the treatment of a lumbar strain and for the further prevention of low back pain.  level of evidence 2A)
A Lumbar strain improves within 2 weeks. Normal functions are restored after 4 – 6 weeks. (level of evidence 5)
- 14.Karnath B. Clinical Signs of Low Back Pain. Hospital Physician. 2003 May. (level of evidence: 5)
- A.T. Patel, A. A. Ogle; Diagnosis and Management of Acute Low Back Pain; Am Fam Physician. 2000 Mar 15;61(6):1779-1786 (Level of evidence: 3B)
- R. A. Dey, J. Rainville, D. L. Kent; What Can the History and Physical Examination Tell Us About Low Back Pain?; JAMA, August 1992- Vol 268, No.6
- A A Narvani, P Thomas an B Lynn. Key topics in sports medicine. Routledge. United Kingdom. 2006. 310p. (Level of evidence: 5)
- M.W Van tulder, B.W. Koes. Evidence based handelen bij lage rugpijn. Medicamenteuze behandeling. Bohn stafleu van Loghum 2004 ( level of evidence: 1A)
- Malmivaara, M.D., U. Häkkinen et al. The Treatment of Acute Low Back Pain — Bed Rest, Exercises, or Ordinary Activity.the new England journal of medicine 1995.
- M. Higgings. Therapeutic exercises. Chapter 19 rehabilitation of the lumbar spine. Davis company 2011. (Level of evidence 5)
- L.D Weiss et al. Oxford amarican handbook of physical medicine and rehabilitation. 2010 oxford university press. (level of evidence 5)
- Meeusen R. Sportrevalidatie. Rug- en nekletsels (deel 2) reeks sportrevalidaties. Kluwer.2001. (level of evidence: 5)
- 8. Gaetano et al. Lumbar strain back to the basics. Sports medicine, 2005 (level of evidence 5)