The Active Straight Leg Raising Test for Sacroiliac Dysfunction

A physical therapist has a barrage of tests if someone is suspected as having a sacroiliac (SI) joint dysfunction.  They can complete distraction or compression of the pelvis, the thigh thrust test, sacral thrust test, March test, palpation of the muscles and ligaments at the pelvis, and assess the alignment of the innominates.  All of these are helpful in determining if the SI joint is the problem but they are difficult to quantitatively measure change.  Mens et al. set out to come up with another clinical test to help confirm and measure SI joint dysfunction.

Their methods are as follows:

  1. Have the patient in supine with their legs straight and relaxed.
  2. The patient is asked to raise the unaffected leg about 6 inches while keeping the knee straight and then lower back down.
  3. Then complete on the affected side.
  4. The examiners assessed if the patient had any tremors in the leg during the leg raise, if there was a compensatory motion at the trunk, if the subject had any verbal and nonverbal emotional expression during the task, and the patient was asked if they noticed any difference between the sides.
    1. The patient was scored from 0-3
      1. 0 = The patient feels no restriction
      2. 1 = The patient reports decreased ability to raise the leg but the examiner assesses no signs of impairment
      3. 2 = The patient reports decreased ability to raise the leg and the examiner examines signs of impairment
      4. 3 = The patient is unable to raise the leg.
    2. A difference in score of 2 or more was considered significant
  5. Then the patient completed the tasks again with a belt fastened either just below the Anterior Inferior Iliac Spines or at the Pubic Symphysis and reassessed for change in ability to complete the task.

To further provide measurable values to reassess as the patient improves I would suggest measuring the hip flexion range of motion if the patient cannot complete the 6 inch leg raise with or without the fastened belt.  Also, you can manual muscle test the legs with and without the fastened belt and document the strength change if the patient can complete the 6 inch leg raise to observe and measure the difference.  Just be aware of the patient’s irritability prior to completing a graded resistance to the leg to avoid flaring up the patient’s symptoms.

If you are having difficulty visualize the test, please watch the video below.

 Reference:

Mens J, Vleeming A, Snijders CJ, Stam HJ, Ginai AZ. The active straight leg raising test and mobility of the pelvic joints.  Eur Spine J. 1999; 8:468-473.

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The role of pain-related fear and avoidance in chronic pain

Fear-avoidance model

(Image directly copied from Vlaeyen & Linton, 2012)

Key Points
• Long-term avoidance of pain-related behaviors due to fear of pain may increase sensitization to pain and pain-related stimuli, decrease self-efficacy, increase expectation of pain, and increase pain perception, ultimately perpetuating pain-related disability and functional impairment.
• Increased willingness to experience pain and graded exposure to situations or behaviors perceived to be threatening is effective in reducing pain-related fears and subsequent pain-related avoidance and disability among individuals with chronic pain.

Fear and Avoidance in the Development and Maintenance of Chronic Pain
Traditional biomedical models of pain suggest that an individual’s pain experience should directly match the physical damage incurred and that similar injuries should result in similar pain. However, pain isn’t that simple. Rarely will two individuals with identical physical injuries report the exact same pain. For that matter, two individuals with the same injury will likely demonstrate differences in impairment and suffering. These observed discrepancies between expected and reported pain and disability suggest a more complex relationship; one that has led researchers to examine the role of psychological and behavioral factors in the development and maintenance of chronic pain conditions.

The fear-avoidance model (Vlaeyen & Linton, 2000; 2012) details a potential pathway for the development of pain disability, affective distress, and physical disuse resulting from anxiety- and fear-related avoidance behaviors and provides a platform for understanding the dynamic relationship between psychological factors and chronic pain. The fear-avoidance model suggests that pain-related avoidance behaviors and withdrawal, as well as increased vigilance toward internal bodily sensations and external threats of pain, play an adaptive and functional role in protecting the body. It’s healthy to avoid behaviors that cause pain – at least in the short-term. For example, bending or lifting heavy objects may be avoided in order to limit lower back pain from a previous injury. Although adaptive in promoting recovery in acute phases of pain, prolonged avoidance and hypervigilance behaviors may serve to maintain or even exacerbate pain symptoms in the long term by inadvertently increasing pain disability and affective distress. That is, long-term avoidance of pain-related behaviors is maladaptive and ultimately increases pain and pain-related disability.

Pain-related fear and negative affective states play an integral role in escape and avoidance behaviors, suggesting that the meaning of pain may be just as important as the actual experience of pain. When pain is feared and viewed as dangerous, an individual may act in anticipation of pain, rather than in direct response to pain. Avoiding movements due to pain-related fears may contribute to physical deconditioning, negative affect or affective comorbidities, and preoccupation with physical and somatic symptoms associated with pain. These effects in turn may increase sensitization to pain and pain-related stimuli, decrease self-efficacy, increase expectation of pain, and increase pain perception, ultimately perpetuating pain-related disability and functional impairment.

The Good News

You don’t need to change a patient’s beliefs or fear of pain to reduce their avoidance of pain-related behaviors. Graded exposure to situations or behaviors perceived to be threatening is effective in reducing pain-related fears and subsequent pain-related avoidance and disability among individuals with trauma-related neck pain (de Jong et al., 2008), upper extremity pain (de Jong et al., 2012), complex regional pain syndrome (de Jong et al., 2005) and chronic low back pain (Vlaeyen et al., 2001; 2002). Exposure-based treatments are some of the most effective and widely-used psychological interventions for anxiety and trauma-related disorders and have gained continuing support in the treatment of chronic pain conditions. By providing education about the role of avoidance behaviors in the maintenance and development of pain and systematically increasing engagement in feared or pain-related behaviors, psychological and physical therapists can effectively reduce pain-related fear and anxiety and enhance effective recovery through confrontation and increased self-efficacy.

References

de Jong, J. R., Vangronsveld, K., Peters, M. L., Goossens, M. E. J. B., Onghena, P., Bulté, I., & Vlaeyen, J. W. S. (2008). Reduction of pain-related fear and disability in post-traumatic neck pain: A replicated single-case experimental study of exposure in vivo. The Journal of Pain, 9, 1123-1134.
de Jong, J. R., Vlaeyen, J. W. S., van Eijsken, M., Loo, C., & Onghena, P. (2012a). Reduction of pain-related fear and increased function and participants in work-related upper extremity pain (WRUEP): Effects of exposure in vivo. Pain, 153, 2109-2118.
de Jong, J. R., Vlaeyen, J. W. S., Onghena, P., Cuypers, C., den Hollander, M., & Ruijgrok, J. (2005). Reduction of pain-related fear in complex regional pain syndrome type I: The application of graded exposure in vivo. Pain, 116, 264-275.
Vlaeyen, J. W. S., de Jong, J. R. Geilen, M., Heuts, P. H., & van Breukelen, G. (2001). Graded exposure in vivo in the treatment of pain-related fear: A replicated single-case experimental design in four patients with chronic low back pain. Behavior Research and Therapy, 39, 151-166.
Vlaeyen, J. W. S., de Jong, J. R. Geilen, M., Heuts, P. H., & van Breukelen, G. (2002). The treatment of fear of movement/(re)injury in chronic low back pain: Further evidence on the effectiveness of exposure in vivo. The Clinical Journal of Pain, 18, 251-261
Vlaeyen, J. W. S., & Linton, S. J. (2000). Fear-avoidance and its consequences in chronic musculoskeletal pain: A state of the art. Pain, 85, 317-332.
Vlaeyen, J. W. S., & Linton, S. J. (2012). Fear-avoidance model of chronic musculoskeletal pain: 12 years on. Pain, 153, 1144-1147.

The Importance of Ankle Range of Motion for Knee Pain

Knee Mechanics

It is important to assess multiple areas of the body when treating knee pain and more specifically patellofemoral pain (PFP).  One major contributor to knee pain is hip strength.  Good hip strength is important to aid in appropriate knee alignment and mechanics.  Another important contributor is foot alignment.  Many individuals with PFP exhibit over pronation of the midfoot/flatfoot.  This will cause the lower leg to turn in and place more stress of the patella on the femur.

But one aspect that I believe needs more consideration is ankle range of motion; specifically ankle dorsiflexion range of motion.

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A study by Rabin et al. found that individuals with PFP had less than optimal movement during a lateral step down test and exhibited significantly less ankle dorsiflexion range of motion (4.7° in weight bearing and 5.3° in non-weight bearing) than individuals with optimal movement and without pain.  More specifically, they found that men had a significant difference of 8.5° with non-weight bearing measurements.

Could this limitation in ankle dorsiflexion range of motion be a precursor for maladaptive behavior found at the foot, knee, and hip?  The researchers proposed that the limitation in ankle dorsiflexion will cause less forward movement of the tibia when walking, running, and going up and down stairs.  This may cause excessive compensatory movement of the midfoot, such as over pronation, in order to get the needed range to complete those tasks.  This will also cause the knee to turn and place more force of the patella on the femur.

A recommendation to improve ankle dorsiflexion for people with PFP is to complete a stretch against the wall or counter holding for 30 seconds and completing 2 times.  Use this stretch (presented in the video below) until knee discomfort subsides and a lunge position with the knee on the floor can be tolerated.

A more dynamic lunge stretch (shown in the video below) can be completed to further improve ankle dorsiflexion range of motion.  Hold this position for 5 seconds and complete 20 times.  These motions should be completed on both sides even of you do not have discomfort at both legs.

 

Limitations of the study:

  1. It was not possible to determine whether limited ankle dorsiflexion range of motion is the cause of abnormal lower quality of movement or a consequence.
  2. The findings are limited to visual assessment of the quality of movement during the lateral step down test.
  3. The subgroup analysis was not preplanned and they completed the analysis only after observing abnormal tendencies in the subjects.
  4. The examiners were not completely blinded to the quality of movement assessment.
  5. The sample of subjects were younger than other populations of people with patellofemoral pain so results should not be generalized to all individuals.

Reference: Rabin A, Kozol Z, Moran U, Efergan A, Geffen Y, Finestone AS. Factors associated with visually assessed quality of movement during a lateral step-down test among individuals with patellofemoral pain. J Orthop Sports Phys Ther. 2014; 44(12): 937-946.

Adhesive Capsulitis: It’s Not So Black and White…Or Can It Be?

adhesive capsulitis

Adhesive capsulitis tends to have a long and painful rehabilitation process.  There is a straightforward progression through the healing process but the time in which to make it through is variable (up to 2 years to recover).

Etiology

The synovial membrane will develop increased vascularity (known as angiogenesis) and hypertrophy leading to adherence to the inferior axillary fold.  The increased vascularity is accompanied by increased nerve growth which is a cause of abnormally high pain at the shoulder.  This will eventually lead to contractures of the rotator cuff (primarily the subscapularis muscle) and further inflammation will cause contractures of the capsule and the coracohumeral ligaments.  This will often tighten the posterior aspect of the shoulder and cause the head of the humerus to translate anteriorly; also known as the “capsular constraint mechanism.”¹

Usually we think of adhesive capsulitis having 3 stages but Kelley et al. described a 4 stage clinical course:

  • Stage 1 – may last up to 3 months and the individual will feel sharp pain at end ranges of motion, achy pain at rest, and sleep disturbance.  At this time there is no growth of adhesions or contractures.
  • Stage 2 – “The Freezing Stage” – may last from 3 to 9 months and is a gradual loss of motion in all directions due to pain.  There is vascular and nerve growth around the capsule.
  • Stage 3 – “The Frozen Stage” – may last from 9 to 15 months and is characterized by a lessening of inflammation but the growth of fibrous tissue.
  • Stage 4 – “The Thawing Stage” – may last from 15 to 24 months and will show a decrease in pain but fibrous tissue may persist.

There are 2 main categories of adhesive capsulitis³:

  1. Primary/Idiopathic Adhesive Capsulitis – this type is not associated with a systemic condition or a history of an injury.  There is no known cause or predisposing factor.
  2. Secondary Adhesive Capsulitis – this type is due to a mechanism of injury or precipitating event and can be broken down into 3 subcategories.
    1. Systemic Secondary Adhesive Capsulitis – having a history of diabetes or thyroid disease.
    2. Extrinsic Secondary Adhesive Capsulitis – the pathology is not directly related to the shoulder but results in a painful and stiff shoulder such as a cerebral vascular accident, myocardial infarction, COPD, chronic liver disease, cervical disc disease, or distal extremity fracture.
    3. Intrinsic Secondary Adhesive Capsulitis – due to a known injury to the glenohumeral joint soft tissues and structures.

∗ A loss of shoulder ROM and pain that is associated with postoperative stiffness should not be considered adhesive capsulitis ∗

Treatment

Before treating adhesive capsulitis you should differentiate a capsular restriction impairment from a muscle flexibility impairment.  A capsular restriction will present with limited shoulder external rotation range of motion that worsens with shoulder abduction and can be treated with joint mobilizations.  A muscular restriction will present with limited shoulder external rotation range of motion that improves with shoulder abduction and should be treated with stretching and soft tissue massage.

Joint mobilizations can be completed in different directions.  Inferior glides have shown to improve shoulder flexion and abduction ranges (the glenohumeral head slides 3mm superiorly for the first 60° of abduction¹) while anterior and posterior glides have shown to improve shoulder internal and external range of motions.  An important question is what will improve shoulder internal and external range of motions the most; anterior or posterior glides?

There are 2 principles that can be followed in using joint mobilizations; the “concave-convex rule” or the “capsular constraint mechanism” (mentioned above).

Johnson et al. states that it is important to follow the capsular constraint mechanism and use posterior glides to the glenohumeral head to stretch the posterior aspect of the capsule.  But in order to optimize your joint mobilizations you should incorporate irritability level.

High irritability individuals will present with pain levels ≥7/10, consistent night or resting pain, pain before end range of active or passive movements, and active motion is significantly less than passive motion due to pain.  Clinicians should use low-intensity joint mobilizations in pain-free ranges and positions.

Moderate irritability individuals will present with pain between 4-6/10, intermittent night or resting pain, pain occurring at end ranges of active and passive motion, and active range of motion similar to passive range.  Clinicians should use moderate-intensity joint mobilizations and progressing amplitude and duration into tissue resistance without producing tissue inflammation.

Low irritability individuals will present with pain ≤3/10, no night or resting pain, pain with overpressures into end range of passive motion, and active motion same as passive motion.  Clinicians should use end-range joint mobilizations with high amplitude and long duration into tissue resistance.

References 

  1. Roudal PJ, Dobritt D, Placzek JD. Glenohumeral gliding manipulation following interscalene brachial plexus block in patients with adhesive capsulitis. J Orthop Sports Phys Ther. 1996; 24(2):66-77.
  2. Johnson AJ, Godges JJ, Zimmerman GJ, Ounanian LL. The effects of anterior versus posterior glide joint mobilization on external rotation range of motion in patients with shoulder adhesive capsulitis. J Orthop Sports Phys Ther. 2007; 37(3):88-99.
  3. Kelley MJ, Shaffer MA, Kuhn JE, Michener LA, Seitz AL, Uhl TL, Godges JJ, McClure PW. Shoulder pain and mobility deficits: adhesive capsulitis. J Orthop Sports Phys Ther. 2013; 43(5):1-31.

Patellofemoral Joint Pain Rehabilitation: How to Strengthen the Quadriceps and Limiting Joint Stress

knee_patella

Patellofemoral Joint (PFJ) pain is the most common knee problem and accounts for 25% of all knee injuries and is more common in females than males.(1)  Conservative treatments may consist of stretching, strengthening, balance exercises, and working on biomechanics.  But the individual dealing with the injury or the person treating that individual should consider appropriate interventions while avoiding exacerbation of symptoms and injury.

In this article, I will focus on quadriceps muscle strengthening as one aspect of conservative treatment.  Usually during a pain flareup an individual will more likely avoid certain positions leading to weakness of the leg muscles and eventually poor mechanics.  To avoid the progressive weakening of the quadriceps muscles it is important to complete exercises.  What exercises would be okay to complete without overly stressing the patellofemoral joint?

An article I just reviewed assessed the force of the patella on the femur during common rehabilitation exercises for the knee; the squat and seated knee extension.  The study showed that completing a squat from 0-45 degrees of knee flexion and seated knee extension from 90-45 degrees of knee flexion would be optimal to avoid overly stressing the PFJ.  Complete 10 repetitions 2-3 times a day and increase 5 repetitions every two weeks until you are able to complete 25 repetitions of each exercise without pain.  These exercises should be incorporated into the initial stages of PFJ rehabilitation until an individual is able to go up and down stairs or transitioning from sitting to standing from a chair without pain.  Then these exercises may be progressed to the full ranges.

Squats from 0-45 Degrees of Knee Flexion

Seated Knee Extension from 90-45 Degrees of Knee Flexion

images2

1. Sueki D, Brechter J. Orthopedic Rehabilitation Clinical Advisor. Maryland Heights, MO: Mosby, Inc.; 2010.


(Click the link below for access to the article)

Patellofemoral Joint Stress During Weight-Bearing and Non-Weight-Bearing Quadriceps Exercises

Purpose: To compare patellofemoral joint stress among weight bearing and nonweight bearing quadriceps exercises.

Methods: They assessed the knee musculature of squatting exercise (weight bearing) and two nonweight bearing knee extension exercises (seated knee extensions with variable resistance and seated knee extensions with constant resistance).  They used 10 subjects (5 male and 5 female) who did not have knee pain.

Results: They found that the squat produced significantly higher PFJ stress from 90-60 degrees knee flexion.  They reported that the two nonweight bearing exercises had significantly higher stresses from 30-0 degrees knee flexion.  And more specifically that the variable resistance produced significantly less stress than the constant resistance.

Limitations: There were 5 limitations with this study.  First, they only studied healthy individuals so the results should not be generalized to other populations.  They did not compare the exercises to a gold standard.  The researchers did not control the trunk position during the squat exercise which could change the muscle activity of the quadriceps.  They considered the segmental accelerations during the nonweight bearing exercises negligible and were not factored into the calculations.  Finally, they only studied concentric muscle activation and recommended that future studies assess eccentric muscle contractions.

Which Gluteus Medius and Maximus Exercises are Most Beneficial?

Weakness in the gluteus muscles tends to be a cornerstone of many injuries in the lower extremities and back.  It is important to strengthen those muscles to take pressure off of joints and correct an individual’s biomechanics.  But what exercises are the most efficient in accomplishing this?

I found an article that assessed 12 common gluteus maximus and medius muscle exercises.  They wanted to figure out which exercise(s) will be most beneficial for those muscles.  They found that the Side-lying Hip Abduction Exercise activated the gluteus medius muscle the most out of all the other exercises and the Single Limb Squat and Single Limb Deadlift activated the gluteus maximus more than all other exercises.

Side-lying Hip Abduction

(Keep the knee extended and the hip in a neutral position while lifting the leg up to about 30 degrees)

Side-lying hip abduction

 

Single Limb Squat

(Stand on one leg and slowly lower by bending the hip, knee, and ankle until the opposite hand touches the foot that is on the ground without rotating the trunk)

Single Limb Squat

Single Limb Deadlift

(Stand on one leg with the knee flexed to 30 degrees and slowly flex the hip and trunk until the opposite hand touches the foot on the ground without rotating the trunk)

Single Leg Deadlift

(Click the link below for access to the article)

Gluteal Muscle Activation During Common Therapeutic Exercises

Study Design: Experimental Laboratory Study

Purpose:  To quantify and compare gluteal muscle activation across 12 common strengthening exercises of varying difficulty.

Methods: The study consisted of examining 21 subjects who were physically active (exercising 60 minutes at least 3 times a week), no pain, no history of ACL injury, and no history of lower extremity surgery.  They used surface EMG electrodes to measure gluteus medius and gluteus maximus muscle activation.  The subjects completed 8 repetitions of each of the 12 exercises in random order.  The exercises consisted of 3 non-weight bearing (clams with hips at 30 degrees, clams with hips at 60 degrees, and side-lying hip abductions) and 9 weight bearing (single limb squats, single limb deadlifts, lateral band walks, forward lunges, side lunges, lunges with rotation, forward hops, side hops, and hops with rotation).

Results:  The Side-lying Hip Abduction Exercise produced significantly greater gluteus medius activation than the 2 clam exercises, lunges, and hip exercises.  The Single Limb Squats and Single Limb Deadlifts had significantly greater gluteus maximus activation (also, equal activation of gluteus medius and gluteus maximus muscles) than the lateral band walks, clams, and hop exercises.

Limitations: Some of the limitations consisted of the potential for cross-talk between muscles during the surface EMG assessment.  Also, the dynamic movement of the hop exercises could cause EMG activity variability.  Finally, there were no non-weight bearing hip extension exercises assessed.

Significantly Improving Shoulder Range of Motion in One Treatment

It can be difficult to treat people with a shoulder musculoskeletal disorder causing limited shoulder range of motion.  There are many ways to conservatively treat these individuals; such as using soft tissue massage (STM), joint mobilizations (JM), muscle strengthening, stretching, proprioceptive neuromuscular facilitation (PNF), modalities, etc.  A multitude of treatments can limit progress when used all at once or when they are not warranted.  I found an article that focused on treating individuals with soft tissue restriction from muscle as opposed to individuals with capsular restrictions by using STM and PNF.

Prior to treatment, the researchers measured glenohumeral range of motion in supine with the shoulder abducted to 45 degrees and again at 90 degrees shoulder abduction.  They defined individuals with muscular restrictions as individuals with an increase in external rotation range from 45 to 90 degrees shoulder abduction.  A capsular restriction presented as individuals with a decrease in external rotation from 45 to 90 degrees shoulder abduction and were not deemed suitable for this type of treatment.

1.  They first treated subjects with soft tissue massage to the subscapularis muscle with the subject supine and their shoulder abducted to 45 degrees and externally rotated to 20-25 degrees.  They poked around the armpit for areas of tissue restrictions and either used sustained pressure or slow deep strokes for 7 minutes.

2.  Then they maintained the shoulder in the same position and completed contract-relax PNF to the subscapularis and internal rotators of the shoulder.  The subject was instructed to complete a maximal isometric internal rotation contraction against resistance for 7 seconds and then maximally externally rotated.  The externally rotated position was help for 15 seconds.  This was repeated 5 times.

3.  Finally, the subject was instructed to complete 5 repetitions of the flexion-abduction-external rotation PNF pattern actively with manual facilitation.

(Click the link for access to the article)

The Immediate Effects of Soft Tissue Mobilizations with Proprioceptive Neuromuscular Facilitation on Glenohumeral External Rotation and Overhead Reach

Design: Randomized-controlled 2-group pretest-posttest, multivariate study of patients with shoulder musculoskeletal disorders

Purpose: To evaluate the immediate effect of soft tissue mobilizations with Proprioceptive Neuromuscular Facilitation to increase glenohumeral external rotation at 45 degrees of shoulder abduction and overhead reach.

Methods: Twenty subjects (10 male, 10 female) with limited glenohumeral external rotation and overhead reach for a duration of 1 year or less were assessed.  The glenohumeral external rotation was measured supine with the shoulder at 45 degrees abduction and overhead reach was measured from the tip of the middle finger on the wall to the floor.  The experimental group was treated with STM to the subscapularis and PNF to the rotators.  The control group received 10 minutes of resting supine on the treatment table.

Results: The experimental group significantly increased external rotation range by 16.4 degrees and the overhead reach by 9.6 cm.

Limitations: This was a single session so the study does not allow for conclusions on effects beyond 1 visit.  The study also did not compare different treatment interventions so other outcomes may be similar for other techniques.

 

 

An Exercise to Help Lower Trapezius Strength and Improve Neck Pain

Here is an exercise option for the last article I reviewed and posted.  I have combined two exercises together Scapular Depressions + Chin Tucks to improve neck pain.  I have posted two Youtube videos to this post.  The Scapular Depression Exercise helps to draw the shoulder blade to the ground by activating the lower trapezius muscle.  The Chin Tuck exercise helps to strengthen the deep cervical muscles and place the head in better alignment during the first exercise.  I prefer combining the two exercises together to get a the most out of the exercise.  I would recommend completing this exercise 2-3 times a day for 12 repetitions and holding each repetition for 5 seconds.

Scapular Depression Exercise

Chin Tuck Exercise

Neck Pain: Look A Little Further to the Lower Trapezius Muscle

Trapezius_muscle_animation2

(Upper Trapezius = Orange; Middle Trapezius = Red; Lower Trapezius = Purple)

 Sometimes I find it difficult to remember to look further than the patient’s area of pain.  When assessing the neck, I may assess the posture of the head and upper back, range of motion of the neck and back, joint mobility, palpations, etc.  I may notice that the upper trapeziuses are overactive and strong but not consider the strength of the lower trapeziuses.  I started to wonder if the strength of the lower trapezius could be a factor for people suffering from certain types of neck pain.

I came across an article that assessed the strength of the lower trapezius muscle in individuals with single sided neck pain.  The article by Petersen and Wyatt found that the lower trapezius muscle on the affected side was significantly weaker than the lower trapezius muscle on the unaffected side.  They also did not want to assume that strengthening of the lower trapezius will help with neck pain even though they found a significant muscle strength difference.

(Click the link below for assess to the article)

Lower Trapezius Muscle Strength in Individuals with Unilateral Neck Pain

Purpose: To examine lower trapezius muscle strength in individuals with unilateral neck pain, as an initial step in determining if impairments need to be assessed and addressed in this population.

Methods: This is a descriptive and within-subject comparative study.  The researchers examined 25 individuals with unilateral neck pain for greater than 3 months and did not have radicular symptoms.  The examiners tested the strength of the lower trapezius by using a handheld dynamometer at the distal forearm with the subjects in prone and the upper extremity in line with the lower trapezius fibers (~130 degrees in shoulder abduction).  The examiners stabilized the contralateral scapula.  They completed 2 measurements and averaged the values.  Each subject was tested bilaterally and the examiners were blinded.

Results: The lower trapezius strength on the affected side was significantly (p<0.001) less than the lower trapezius strength on the unaffected side with a mean difference of 3.9N.  They did not find a correlation between duration of neck pain and lower trapezius weakness.

Limitations: The researchers did not include an asymptomatic group for comparison.  Also, there is conflicting evidence of which manual muscle test position for the lower trapezius and placement of the dynamometer are optimal.

Acromioclavicular (AC) Joint Motion During Shoulder Elevation

AC jointI’ve noticed that I may not be paying as much attention to the acromioclavicular joint, also known as the AC joint, when treating patients recovering from shoulder pain and dysfunction.  This joint is an important component in achieving proper kinematics of the shoulder and improving motor control.  I wanted to touch upon the AC joint and its normal motion during shoulder movements.

I came across an article that measured the motion of the AC joint as well as the sternoclavicular joint (SC joint) and the scapulothoracic junction.   The researchers measured shoulder abduction to 90 degrees in cadavers and healthy living subjects.  They found the AC joint increased internal rotation motion of about 4.3 degrees, upward rotation of 14.6 degrees, and posterior tilting of about 6.7 degrees in living and cadaver subjects.  (They mentioned that excessive AC joint internal rotation can cause excessive anterior tilting of the scapula leading to impingement of the subacromial tissues during shoulder elevation.) They talked about the importance of the coupling motion of the clavicle during posterior rotation which combined with greater scapular upward rotation than posterior tilting at a ratio of 3:1.  They mentioned that if the clavicle only elevates and does not rotate, the coupling motion involves greater anterior tilt of the scapula than upward rotation.  They also reported motions measured at the SC joint and found about 6 degrees of retraction, elevation of 6 degrees, and posterior rotation of 10 degrees during healthy shoulder abduction.

Knowing these values and the coupling motions may assist a practitioner with improvement of shoulder dysfunction and prevention of future repetitive shoulder injuries.

(Click the link below for access to the article)

Three-Dimensional Acromioclavicular Joint Motions During Elevation of the Arm

Purpose: To examine 3-D movement at the AC joint during both active elevation in asymptomatic subjects and passive elevation in cadaver specimens with no signs of shoulder injury.

Methods: The dominant arm of 30 healthy living subjects were studied who did not have a history of shoulder pathology and were also cleared using a clinical screening exam.  There were 16 males and 14 females studied.  The researchers also studied 8 fresh frozen cadaver specimens without shoulder joint degeneration and no known history of shoulder problems.

They used electromagnetic tracking with motion monitor software.

The subjects completed 3 repetitions of shoulder abduction at a speed of 3 seconds up and 3 seconds down while in an upright position.  The cadavers were placed in an upright position as well and were passively ranged in abduction.  All motion was measured from 0 degrees to 90 degrees shoulder abduction.

Results: The researchers found that the AC joint demonstrated increased internal rotation of about 4.3 degrees, increased upward rotation of 14.6 degrees, and increased posterior tilting of approximately 6.7 degrees.  All these values were significant.  They found similar values in the cadaver measurements.

Limitations: The researchers mentioned 4 primary limitations.  The first was that there was potential error in AC joint position due to sensor placement and movement of the sensor on the skin over the bone surface.  The second is that they did not have direct validation of the AC joint.  The third limitation is that they only studied subjects to 90 degrees of shoulder abduction and not greater due to concerns about the tracking mechanism.  Finally, they stated that the results cannot be generalized due to the study examining the specific subject population age, studying individuals without impairments, and only studying dominant shoulders.