Physio Charlie

This is my colleague Cath's IST this week:

Ms/Mnth:Multifidus

 

Anatomy:

Multifidus lies deep to semispinalis and erector spinae in the groove between the transverse and spinous processes of the sacrum to C2; it consists of a series of fleshy and tendinous fascicles.

Proximal Attachment

• It arises inferiorly from the dorsal surface of the sacrum as low as the fourth sacral foramen (deep to the tendon of erector spinae), the aponeurosis of erector spinae, the posterior superior iliac spine and posterior sacro-iliac ligament. In the lumbar region it arises from the mamillary processes of L1 to L5, in the thoracic region from the transverse processes of T1 to T12 and in the cervical region from the articular processes of C4 to C7.

Distal Attachment

• The fascicles pass obliquely supero-medially to attach to the whole length of the spinous processes of C2 to L5. The muscle is arranged in three layers: the deepest layer attaches to adjacent vertebrae, the intermediate layer to the second or third vertebra above and the superficial layer to the third or fourth vertebra above.

 

Actions:

• The precise actions of multifidus as well as those of the other short muscles in the back are not fully understood. It is thought that its main role is as a stabilizer of the vertebral column, which is probably of greater functional significance than its role in producing movement. Bogduk (1997) believes that in the lumbar spine; the obliquely orientated fibres of the deepest portion of multifidus; do not play a role in the production of spinal rotation as the lumbar spine has minimal range of rotation. He states the primary role of these deepest fibres is to resist the rotation generated by the obliques, therefore providing segmental stability. Globally the muscles are thought to play a role in extension, lateral flexion and rotation the vertebral column, acting as a series of extensible ligaments, adjusting their length to stabilize adjacent vertebrae (interactive spine).

 

Assessment:

Looking at:

1. Muscle atrophy
2. Consistency of muscle fibre i.e.: internal structure.
3. Contraction: whether it is  a) symmetrical

b) at adjacent levels

c) Fatigue levels: gold standard to hold contraction for 15sec x 2

 

Ultrasound Imaging:

• Changes in consistency of the multifidus can be easily observed using ultrasound imaging. The ultrasound appearance of muscle is usually dark because of its high fluid content (blood). The presence of fatty infiltration, fibrous changes or scar tissue (non-contractile tissue) leads to a change in the appearance as non contractile tissue is white in appearance. These changes can be seen at specific vertebral levels and are not difficult for the clinician to detect using ultrasound imaging.
• In contrast, measurement of the multifidus cross-sectional area requires extensive training and practice to become proficient. Care should be taken as measurement error may be greater than the changes measured with rehabilitation; therefore not reflecting the actual changes (Richardson et al, 2004).

 

Clinical Assessment:

Palpation of the muscle at each segment with the patient relaxed in prone position.

  

(Page 195 - 196: Richardson et al, 2004)

 

• The muscle is palpated adjacent to the spinous process.
• Side-to-side comparison is made at each level.
• Comparison is made of the segments above and below.
• Feel for any loss in muscle consistency at each segment (spongy feeling).

 

For stabilization and joint protection, it is the activation of the deep multifidus fascicles that need to be particularly tested. They contract isometrically and segmentally. Therefore for assessment an isometric and segmental contraction must be used.

 

Procedure

  

(Page:196 Richardson et al, 2004)

• Encourage the patient to visualise multifidus as deep triangles running down from every spinous process. Demonstrate a contraction of a muscle e.g.: swelling of the forearm with making a fist.

 

(A: deep and B: Superficial fibres Lumbar multifidus)

 

• A variety of hand positions can be used to perform the test. Thumbs, index or middles fingers or your thumb and index finger either side of the segment.
• It is important to sink your fingers in firmly before asking the patient to contract (swell) their muscles. But it is also important for the clinician to release the pressure as the patient contracts the muscle, otherwise, the compressive force could inhibit the contraction.
• Prompts to the patient: ‘gently swell your muscles under my fingers without moving anything else, and breathe normally’…..
• Ideally the muscle will harden as it generates tension. There should be a similar contraction between adjacent segmental levels and there should be symmetrical contraction between left and right sides at the same segmental level.
• As a gold standard this contraction should be able to be held for 15 seconds and consistently repeated 2 times.
• The inability to segmentally activate a symmetrical contraction indicates a loss of control of the deep segmental fibres of Lumbar multifidus (Richardson et al, 2004).

 

Phasic facilitators: if the patient is struggling to elicit any contraction.

 

These manoeuvres can be used to demonstrate the muscles action:

Cough

Laugh

Forced expiration

Lift, push or pull against resistance.

However, this type of contraction employs predominately phasic recruitment and is not appropriate for motor control stability re-training!

 

• Optimal facilitation and re-training requires achieving control at an appropriate low load facilitation and feedback.

 

• The prone position is not necessarily the best position to teach or facilitate the activation of lumbar multifidus if it is dysfunctional. It is unloaded and there is no weight-bearing facilitation and so could be considered a motor challenge. For the majority of patients, upright postures, such as sitting or standing, are the positions where it is easiest to facilitate and teach the correct activation of lumbar multifidus.

 

• During active re-training of lumbar multifidus it is also essential to identify and eliminate various substitution strategies and faults.

Substitutions to be avoided

OBSERVATION	IMPLICATION
No palpable contraction	More effort required
Spinal movement	Global substitution
Pelvic movement	Global substitution
Bracing	Global co-contraction rigidity & excess IAP
Pushing back from hips and legs	Global substitution

 

• Clinically, it seems acceptable to feel a definite contraction of the oblique abdominals, transverse abdominis and a sensation of bracing during segmental multifidus facilitation.

 

Re-training of Multifidus

• Re-training must be facilitated in a pain-free posture or position.
• The neutral spine posture is an ideal position for this.
• The simple process of achieving a neutral spine posture may significantly activate transverse abdominis and lumbar multifidus in some subjects with low back pain.

 

Specific unloaded facilitation

 

Tactile feedback

  

 

• Sit with the spine in neutral alignment. Place fingers / thumbs on the muscles just to the side of the vertebrae and let them sink firmly into the muscle.
• Lean slightly forward from the hips (keeping the spine neutral) and feel the muscle tension.
• Then lean slightly back from the hips until the trunk is directly over the centre of gravity and the muscles relax.
• In this position with the muscle initially relaxed, instruct the patient to locally (or swell) the muscles into the finger and thumb.
• Ideally the muscle will harden as it generates tension. There should be a similar contraction between adjacent segmental levels and there should be symmetrical contraction between left and right sides at the same segmental level.
• The contraction should be able to be maintained for 10seconds 10 times.

Movement and load facilitators

 

Contra-lateral arm lift

 

• Start in sitting and progress to standing.
• Palpate the dysfunctional multifidus with one hand and lift the opposite arm forward and away from the body. Repetitively lift and lower the arm from neutral to 90º flexion and back to the side. Do not allow the spine or pelvis to move.
• The contra-lateral multifidus activates automatically to counter-balance the spinal movement of the arm loading during concentric lifting and eccentric lowering of the arm.
• There are 2 points during the repetitive flexion when multifidus activity diminishes (i.e.: when no load to counter-balance). 1) When the arm is hanging by the side and 2) When the movement changes from lifting to lowering.
• The motor challenge and therefore the re-training exercise is to sustain the contraction during the points when multifidus activity decreases. Maintained for 10 seconds of repetitive movements 10 times.
• To progress also you can make the arm movements faster.

Clinically, this is useful for low back pain associated with upper quadrant loading e.g.: throwing, swimming and racquet sports.

 

Walk Stance: Forward weight transfer

 

 

• Stand with one foot in front of the other as in normal gait and with full weight on the rear foot. Palpate the dysfunctional multifidus on the rear foot side and move the body weight forward onto the front foot.
• The muscle will activate during forward and lateral weight transfer away from the rear foot because it is load facilitated in preparation to support that side of the pelvis and control pelvic rotation during the swing phase of gait.
• Multifidus should activate just after heel lift. If it does not activate until the weight is fully on the front foot the timing is late. Timing may be delayed for several reasons:

1) Pelvic sway

Pelvic sway is a powerful inhibitor of lumbar multifidus and if pelvic sway leads the weight shift multifidus activates late, if at all. Correction is achieved by leading weight transfer with the sternum.

2) Over rotation of the pelvis

Bogduk (1997) suggests the role of the segmental or oblique fibres of multifidus are to counter-act the rotation moment of the oblique abdominals. If, during weight transfer, the pelvis over-rotates away from the front foot then the oblique abdominals are not activating efficiently to control pelvic rotation. Consequently, multifidus also is not activated efficiently. Correction is achieved by controlling pelvic rotation and ensuring that the pelvis faces the direction of weight transfer.

3) Rear foot gluteal inefficiency

The front leg pulls the weight forward instead of the gluteal muscles on the rear leg pushing the body forward. Correction is achieved by conscious activation of the rear foot gluteals to push the body forward.

The motor control challenge and therefore the re-training exercise is to try to sustain the contraction during the points when multifidus activity decreases. Try to maintain active muscle tension during slow transferral of weight back from the front foot to the rear, just prior to heel touch. Sustain contraction while repeating forward and backward movement for 10seconds 10 times.

 

Clinically useful for low back pain associated with gait e.g.: walking, running.

 

  

References:

Bogduk: 1997. Clinical anatomy of the lumbar spine and sacrum. Edinburgh. Churchill Livingstone: 1-261

 

Richardson, Hodges and Hides: 2004. Theraputic exercise for lumbar stabilization: A motor control approach for the treatment and prevention of low back pain. Churchill Livingstone.

 

Interactive spine: http://www.owlnet.rice.edu/~kine351/spine_biomechanics.pdf