What is Slumped Spinal Posture and What Are its Causes?

Introduction to Slumped Spinal Posture

Slumped posture is often caused by collapsing the upper body forward to use digital devices. Permission: Joseph E. Muscolino.

Slumped spinal posture is a term that describes a slumped flexion posture of the spine. It involves excessive posterior tilt of the pelvis, decreased (hypo) lordosis of the lumbar spine, excessive (hyper) kyphosis of the thoracic spine, hypolordosis of the lower cervical spine, hyperlordosis of the upper cervical spine, and a protracted head. If severe enough, then instead of being hypolordotic, the lumbar spine and/or cervical spine could even have a reverse curve, in other words be kyphotic (Table 1). Other terms exist to describe this condition or aspects of it, including flat-back, posterior pelvic swayback, rounded back, military neck, and forward head.

Like most postural distortion patterns of the spine, the key lies in the posture of the pelvis because the pelvis is the foundation for spinal posture. With slumped spinal posture, the pelvis is excessively posteriorly tilted compared to anatomic position. Typical healthy pelvic posture in the sagittal plane involves a sacral base angle of approximately 30 degrees of anterior tilt (and angle formed by a line drawn along the sacral base that intersects with a horizontal line). With slumped spinal posture, the client’s/patient’s pelvic anterior tilt is decreased or even reversed (in other words, posteriorly tilted beyond level).

Table 1: Slumped Spinal Posture

Causes of Slumped Spinal Posture

The principal cause of slumped spinal posture is prolonged postures of sitting with the pelvis in posterior tilt. This type of seated posture is typical when we sit in such as way that our back is not against the back of the chair, or perhaps we sit against the back of the chair, but the chair has insufficient lumbar support. Instead of sitting up straight as is recommended, we sit in a lazy slumped fashion. This allows our pelvis to tilt/roll backward, causing our lumbar and thoracic spine to flex in an attempt to bring the center of weight of the trunk back anteriorly. This increased flexion of the thoracic spine continues into the lower cervical spine bringing the center of weight of the neck and head anterior to the trunk and projecting (protracting) the head forward. If the upper cervical spine and head were to continue the posture of excessive flexion, the head would be oriented downward and we would be looking at the floor in front of us, so as a compensation our upper cervical spine becomes hyperlordotic to bring our eyes and inner ears back to level. The result is a slumped posture of nearly the entire spine, with our spinal joints in a loose-packed posture of flexion and the center of weight of our head far anterior to the trunk.

Any imbalanced skeletal posture will have consequences upon the musculature. A pelvis in excessive posterior tilt shortens the hamstrings and anterior abdominal wall musculature. By the principle of adaptive shortening, these muscles usually become hypertonic (tight, locked short). Because the neck and head are imbalanced anteriorly, the extensor musculature of the upper trunk and neck will be stretched but will have to tighten to create a force of extension to prevent the head from falling into flexion with gravity. Therefore the musculature of the posterior upper back and lower neck will become stretched and tight (locked long); and because of the hyperlordosis (increased extension) of the upper cervical spine, some of the shorter muscles located in the suboccipital region will become short and tight (locked short).

Long-standing tightness of musculature will usually result in discomfort or pain, as well as the development of myofascial trigger points (TrPs), causing further pain both locally and referred. Tight musculature can then play back on the skeletal joints that they cross, causing restricted motion (joint hypomobilities), which can cause even further discomfort and pain when movement is attempted. Tight hamstrings pull via their myofascial meridian continuation through the sacrotuberous ligament onto the sacrum, restricting sacroiliac joint motion. Tight thoracolumbar flexor muscles restrict extension (as well as other motions) of the back. Increased trunk flexion also closes down on the thoracic cavity, making it difficult to take in a deep breath. Tight anteriorly located pectoralis musculature protracts our scapulae and medially (internally) rotates our humeri at the glenohumeral joints, with concomitant effects upon motion of the upper extremity. And tight cervical musculature locks cervical spinal joints. In addition, tightness of upper cervical musculature that attaches onto the head can cause tension headaches.

The longer we allow ourselves to sit in a slumped posture, the more imbalanced is our spine and the more gravity pulls our trunk toward flexion, increasing the severity of this postural distortion pattern. Further, this posture becomes patterned into the physicality of our body as well as the functioning of our nervous system. The flexor musculature of the trunk and lower neck, and extensor musculature of the upper neck and head become shorter and tighter, with fascial adhesions (“fuzz” in the parlance of Gil Hedley) effectively “gluing” the region taut, as well as the baseline muscle tone becoming entrenched within the neural patterning of the nervous system (via neural facilitation). Further, the muscles opposing this pattern become weaker as they are stretched long, thereby becoming increasingly unable to oppose the flexion distortion of the spine. The over all result is that once begun, this pattern progressively worsens as we age.

Therefore, it is clear that the effects of sitting in a lazy slumped manner are many. Unfortunately, with the increased use of digital devices, the number of hours that we spend sitting in a slumped posture is increasing. This is especially true for our children who are growing up in our ever-increasing digital world, and whose body tissues are still developing and therefore more vulnerable to the effects of bad posture. Although all digital devices facilitate the tendency toward a slumped posture, smaller devices held low in front of us are the worst offenders: these include laptops, tablets, smart phones, and other smaller video games that are held in our hands.