Updated Evidence Directly Links Thoracic Spine/Posture to Shoulder Function (Physician Update June 2021)

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Peak Performance Physical Therapy & Sports Training

 

EVIDENCE-BASED PRACTICE UPDATE

June 2021

 

Is Shoulder Pain and Mobility Loss Really The Shoulder’s Fault?

 

 

  

by Allison Pulvino, PT, MSPT, CMP, FAFS

 

CURRENT EVIDENCE

Malmstrom et al. A Slouched Body Posture Decreases Arm Mobility And Changes Muscle Recruitment In The Neck And Shoulder Region. Euro J Appl Physiol, 2015. 115: 2491-2503.

 

Background:

Shoulder pain is one of the more common areas of the body to develop pain and limitations, and it is thought that having a slouched posture due to congenital reasons, prolonged desk work, or ADLs requiring repeated flexed postures. When the body alignment changes, joints, and muscles have to change how they move through their available range and Malmstrom et al. want to see if there is a correlation between increased thoracic kyphosis and increased work for shoulder muscles as a result, including upper trap, lower trap and serratus anterior. 

 

Methods:

Twelve male subjects (23.3 +/- 1.5 years) performed maximum arm elevation in both upright and slouched postures with a 3D movement and EMG recording arm movement and spine movement, as well as EMG activity in the upper trap, lower trap, and serratus anterior. 

 

Results:

Slouched posture resulted in a decreased total arm elevation by 15degrees and a decreased arm velocity by 8% during upward and downward arm movements. The peak muscle activity in a slouched posture also increased in all three muscles: UT +32.3%, LT +48.6%, SA +20.9%. The total muscle work with upward movements in a slouched posture increased significantly as well: UT +36.6%, LT +89.0%, SA +19.4%. Downward movements had increased total muscle work as well: UT +29.8%, LT +122.5%.

 

Limitations:

The main limitation in this study is the 12 participants being asked to create an increased thoracic kyphosis. Although the position of the spine will be the same nonetheless, the muscle recruitment could possibly be much different if there is a prolonged positional spinal change for true chronic spinal positions instead of an instantaneous forced conscious change.

(We’d love to hear your professional insights on this topic.  Let me know your thoughts after reading this summary at PT@PeakPTRochester.com or if you have a patient case you'd like to discuss)

 

SUMMARY:   

While there is not a singular “cause” underlying non-traumatic shoulder pain the topic of “poor posture” often is acknowledged but risks becoming so routine in the minds of clinicians and certainly the public that its role too often gets neglected or even dismissed during rehab.  This study provides good foundational “mechanisms” of evidence to compel both clinicians and patients to fully appreciate the literal negative impact accentuated kyphosis has on shoulder demands and function.   Malmstrom et al examined the association between an increased thoracic kyphosis and changes in shoulder kinematics and muscle recruitment/activity in the upper trap, lower trap, and serratus anterior. Their findings showed a positive correlation with both a decrease in maximal overhead shoulder ROM and an increase in muscle work required to elevate the shoulder overhead during increased thoracic kyphosis as compared to normal posture.  This study provides valuable data to motivate patients to take the connection of postural-focused manual therapy and especially exercise to their shoulder recovery seriously.   It also provides a valuable reminder to referring physicians as they order Physical Therapy and also are scrutinizing care choices for patients who may appear to be “failing” initial therapy.  

 

 

THE PEAK PERFORMANCE PERSPECTIVE

It has been pretty commonplace to assess a patient with shoulder pain and hear the main aggravating movement is reaching overhead. Both doctors and physical therapists alike have heard this many times over, yet each patient may have other limiting factors needing further assessment. As a referring physician, the expectation most often is that the Physical Therapist must “play further detective” to see what body structures are potentially contributing to pain and limitations,  determining how to address both the local tissue pain/inflammation along with necessary ROM/strength/neuromuscular retraining work.  At Peak Performance PT we’re in full agreement with what  Malmstrom et al confirmed in this particular study, that an increased thoracic kyphosis does affect overhead shoulder mobility and muscle efficiency. And while that fact may not seem like “rocket science” (and is generally well known and understood in musculoskeletal care), it all too often ends up being brushed by the wayside by all the various local shoulder exercises available.  

 

When hearing a patient’s history of their present shoulder complaint, repetitive overhead reaching activities obviously stand out in our mind as physicians or therapists as being potential causes for why this individual is in our office.  For example, gardening for 4 hours in the afternoon which includes leaning over (kyphosis) and reaching out or maybe it’s painting walls...and then pain is felt later that night putting dishes away in the top kitchen cabinets or changing a light bulb.  Malmstrom et al’s data help provide a “connecting of the dots” for many cases that help us as clinicians appreciate why the shoulder pain developed but also empowers patients to realize how this talk about posture is more than just your grandmother’s old warnings about sitting up straighter.  It helps bridge the gap between a shoulder that is painful and the thoracic spine that “feels fine” to them and therefore seems unimportant and unrelated.  For some patients, the thoracic kyphosis was induced by positioning, as in the gardening example with temporary thoracic flexion posturing.  For others, they do have generally accentuated thoracic kyphosis, which leads also to the protracted scapula and pec minor shortening, affecting scapulohumeral mechanics. 

 

We see shoulder patients who’ve sometimes been given generic HEP sheets or found shoulder rehab programs on the internet that may even include “postural exercises” like simple scapular retractions.  We don’t find those adequate at stimulating change in most patients, despite possibly “checking the box” as having addressed posture.   Other times we see “failed PT” cases where plenty of appropriate local shoulder exercises were done but too often patients indicate “the therapist never put their hands on me”  (ie. manual therapy)  - especially for the thoracic spine and scapula.   While as clinicians we both know these cases aren’t surgical, but as referring physicians it’s difficult to motivate patients to “try PT again” If they had already been through physical therapy and they only feel slightly better and are still limited at tennis or lifting their toddler into the car seat...etc.  Patients are simply  looking for answers and solutions that work...but they also often ask  “what’s going to be different ‘this time with my PT?”

 

As a referring physician, you also play a key role in prefacing the PT experience too.  Providing patients evidence like Malmstrom et al found, noting the significantly increased load on muscles and the loss of ROM with increased kyphosis it helps “connect the dots” for the patient as to why “out of the blue” this developed.   When you confidently note that their PT will be addressing their postural issues it also reinforces that their physician and PT are on the same page and to feel confident they actually don’t need shoulder surgery like their sister or neighbor did, and physical therapy can help them recover.

 

Protocol type approaches may work for a limited number of patients long term but at Peak Performance, we find a very high percentage of our shoulder pain patients do have scapulothoracic factors that potentially are contributing.  They’re evaluated on Day One as one of our clinical standards.  It’s a simple concept associated with our specialization in Applied Functional Science – the kinetic chain components, especially adjacent joints/structures, must be evaluated as integral parts of understanding the stresses on that local injured/painful shoulder tissue. 

 

We find that working on the body as a whole system will always find other regions that are secondary factors of pain, but still affect ADL life. For example, if someone sits for work 40 hours per week and has a slightly increased thoracic kyphosis, they may also need to have their psoas and pectoralis minor flexibility in the sagittal (but also frontal and transverse) plane assessed likely potential kinetic chain limiters of full overhead shoulder mobility.  Tight hip flexors can lead to a forward pitched spine in standing and therefore disadvantage full elevation similarly to a thoracic kyphosis pre-positioning.  A restricted pec minor that prevents adequate posterior tipping, as per the commonly referred Upper Crossed Syndrome, and also popularized by Kibler and others will clearly lead to abnormal forces at the shoulder and impingement. 

 

Since flexion reaching while bent over in thoracic flexion or upright in kyphotic postures disadvantages normal shoulder function, then a key focus should be improving thoracic extension, scapular posterior tipping, and upward rotation.  Although it’s not always easy to directly focus solely on gaining sagittal plane mobility.

 

Traditional PT exercises work serratus anterior as a scapular protractor, isn’t scapular protraction related to more thoracic flexion? Is a lack of protraction function what the serratus was lacking?  Asking a patient how their prior PT was going and what exercises they were doing can shed some light on this topic. They may have been performing typical overhead arm stretching, scapular protraction exercises with weights, and then standing or prone back extensions. But these exercises initiate movement in neutral (their kyphosis) where the maximum spinal range may already be achieved. Focusing away from the end range and tweaking spinal extension while biased in another plane may be more beneficial and help stay away from the pain provocation.

 

Addressing the “other” thoracic planes of motion can also be critical, though not a specific point of the Malmstrom et al study.  Seeing frontal plane thoracic limitations with proper mobility assessment can shed some light on why abduction or lateral overhead shoulder reaching is painful, as the scapular upward rotation has to happen to prevent impingement in the subacromial space. In the same way that a sagittal plane thoracic kyphosis affects especially sagittal plane scapular and thereby GH mechanics for elevation, we must remember that frontal and transverse plane thoracic to shoulder mobility connections also exist. It is not common to have pure sagittal shoulder overhead flexion without coupling in some side bending and rotational movement, for example with swimmers and throwers.

 

Every individual has specific limitations when shoulder pain is the primary complaint.   Directly assessing someone’s multiplane shoulder ROM but also especially adjacent (and distant) kinetic chain 3D function can shed some light on how many different regions of the upper quadrant or even the hips and pelvis can be affecting their life in a negative and inhibiting manner. Normal and pain-free shoulder elevation with proper scapulohumeral rhythm can be achieved when proper spinal mobility and the correct use of shoulder muscle recruitment is trained, always in a manner that is specific for each patient.

 

The case below demonstrates how important manual therapy and specific functional exercise approaches were helpful in resolving symptoms and restoring function for a very typical shoulder pain case. 

 

THE PEAK PERFORMANCE EXPERIENCE

Doris states: “Watch how I can lift my arm all the way now! It doesn’t even hurt!” 

HX: Doris is a 72-year-old female with ℅ L shoulder pain from “reaching too far and too much” she believes. Sx’s started to be referred down to the elbow and she lost the ability to reach her L arm in all directions. She also reported that sleep became almost impossible. No trauma reported in the past.

Subjective: Doris reported 8/10 L shoulder pain with any active L shoulder movement. She was unable to use it for any ADLs initially and could not sleep well or lean on L arm.

Objective: Unable to tolerate any active ROM so special tests NT. TTP all RC muscle bellies and tendons including proximal bicep. No neural involvement. All UE dermatomes intact. Cspine mobility screening negative for radicular sx’s. Severe Tspine kyphosis with dowager’s hump.

 

 

MEASURE  ( *=pain)	Evaluation  (limited due to severity of Sx)	Discharge
Shoulder flexion (deg.)	130* (PROM only)	1520 AROM
Abduction (deg.)	NT due to pain	1200AROM
ERn (deg.)	42*	650
ER 90(deg.)	NT due to pain	700
IR 90 (deg.)	NT due to pain	800
Tspine rotation	L 180, R 300	NT
Cspine rotation	L 50%, R 75%	B 75%
Cspine ext	50%*	75%
Cspine SB	L 50%, R 25%	50% B
Tspine ext	UNABLE d/t L pain	50% with L shoulder flexion overhead
Apley's Scratch test ER	L Unable, R T1	T1 B shoulders
Apley's Scratch test IR	L L5*, R L1	L3 B shoulder (no pain)

 

 

Treatment:  

Modalities: High-intensity laser treatment, 2 sessions, entire L GH jt capsule, and periscapular soft tissue.

Manual: Tspine rotation and extension mobs with WB lateral flexion mobs. GH mobs for post and inf capsular mobility. Soft tissue mobilization UT, levator, teres major, pec minor, and infraspinatus.

Exercises: Spinal extension active self-mobilizations in WB, spinal AROM drills for FR and TR plane spinal mobility, PROM GH flexion/abduction/ER. AROM UE overhead drills with spinal extension and scapular elevation with BW and weights for progression, TR plane spinal rotation with weighted diagonal pattern TR plane loading and spinal extension loading in standing, FR plane spinal load for shoulder and ROM progressing from AAROM to AROM with weight.

 

Outcome:

Pt is able to sleep without pain, carry groceries in L arm, reach overhead in flexion and abduction without pain onset, and can grab objects in her kitchen cabinets overhead without pain.