Exercise professionals are committed to maintaining and improving the functional independence and physical performance of their clients. Most exercise professionals agree that good posture is essential for attaining these goals. It is often observed in the literature that a skeletal framework and/or spine that is misaligned may result in a cascade of bodily problems, most notably an impediment of the electrochemical messages of the nervous system (since the spine is the pathway for the nervous system to and from the brain) (Edmond et al. 2005). Healthwise this is of paramount concern, since the nervous system is involved in the control and regulation of most bodily system functions. This article reviews posture from a health perspective. Included are an overview of good and faulty posture; key points to be aware of in assessing lateral, frontal and posterior posture positions; and a discussion of posture as it affects health for different sectors of the population.
The word posture comes from the Latin verb ponere, which means “to put or place” (MedicineNet.com 1999). Posture refers to the position of the human body and its orientation in space.
Britnell et al. (2005) define posture as a state of skeletal and muscular balance and alignment that protects the supporting structures of the body from progressive deformity and injury. Whether a person is erect, lying, squatting or stooping, good posture allows the muscles of the body to function with maximum efficiency. In their research review, Kritz and Cronin (2008) add that with good standing posture the body’s joints are in a state of equilibrium (vertical and rotational forces balanced) with the least amount of physical energy being used to maintain this upright position.
Thus, as observed in the standing position, if a vertical line tracks from the neck to the tailbone and through the lower limbs, the body will not have to adjust to counter the forces of gravity (Kritz & Cronin 2008). Furthermore, Kritz and Cronin propose that a body in equilibrium theoretically is capable of doing the most efficient work.
In poor, or faulty, posture (aka postural dysfunction), there is an imperfect relationship among various skeletal structures of the body, and this may produce strain on the body’s supporting framework (Britnell et al. 2005). With faulty posture, the body is balanced less efficiently over its base of support. Therefore, any restriction, imbalance or misalignment of the musculoskeletal structures will have an adverse effect on the efficiency of movement.
Skilled personal trainers seek to assess their clients’ postural patterns and, more importantly, to target abnormal patterns such as lordosis (abnormal inward or forward curvature of the vertebral column) and kyphosis (abnormal curvature of the spine, causing a hunchback). A postural assessment provides an objective means of identifying a client’s postural concerns and establishing a direction for appropriate exercise program design. See Figure 1 for a comparison of common posture types and their resultant muscle imbalances.
Posture can be evaluated statically (stationary position) and dynamically (in motion) (Britnell et al. 2005). In both cases, joint positions and skeletal alignment can be assessed, as well as muscle length (i.e., stretch) and force production capabilities. Kritz and Cronin (2008) note that the relationship between static posture assessment and dynamic movement screening is unclear in the research. Although some fitness professionals use dynamic screening techniques with clients, the research supporting these techniques needs further validation through independent research.
Norris (1995) states that standing side posture should be assessed using the plumb line reference point. Have the client stand with the plumb line just in front of the lateral malleolus (lower end of the fibula that forms the prominent bulge on the outer side of the ankle). In optimal posture, this line passes through the midline of the knee, the lumbar vertebrae, the shoulder joint, the cervical vertebrae and the earlobe (see Figure 1).
Kritz and Cronin (2008) suggest assessing the following checkpoints in standing side posture (this list describes optimal posture):
- head: neutral, with no forward or backward tilt
- cervical spine: slight anterior curve
- scapulae: flat against upper back
- thoracic spine: slight posterior curve
- lumbar spine: modest anterior curve
- pelvis: anterior superior iliac spine in same vertical plane as symphysis pubis
- hip joints: neutral, neither flexed nor extended
- knee joints: neutral, neither flexed nor hyperextended
- ankle joints: neutral, with leg vertical to sole of foot
When standing posture is viewed from the front (with feet approximately 3 inches apart), a vertical line should divide the body into two similar halves. Norris (1995) suggests that the anatomical landmarks to compare for horizontal level on both sides of the body include the lateral malleolus (ankles), patella (knees), anterior superior iliac spine (hips), acromion process (highest point of shoulders) and ears. It is also important to look for muscular or structural differences in this frontal-view assessment. Kritz and Cronin (2008) add that the feet should be in a neutral position with no signs of pronation or supination. They suggest continuing the posture check from behind, observing the following (see Figure 2):
- head: neutral, with no tilt or rotation
- shoulders: level, with no depression or elevation
- scapulae: medial borders parallel and approximately 3–4 inches apart
- thoracic spine: straight with no lateral curve
- lumbar spine: no lateral curve
- pelvis: posterior superior iliac spines in the same plane
- lower extremities: straight, not bowed or knock-kneed
- feet: facing parallel or with toes slightly out; no pronation or supination
Posture and Good Health
If the body segments are out of their optimal alignment for extended periods of time, the muscles eventually adapt by either shortening or lengthening (depending on the position) (Hrysomallis & Goodman 2001). Novak (2004) adds that prolonged misalignment adversely affects nerve tissue and function and that the adaptive changes in muscle tissue (whether lengthening or shortening) result in muscle imbalances, which can have a number of health consequences. The particular health issues caused by posture dysfunction tend to vary by population.
Posture Health for All Ages: Forward-Head PostureForward-head posture (FHP) is the most common form of poor posture in all age groups. People with FHP tend to develop a habitual head misalignment while sitting at a computer workstation, working on hobbies, playing video games or driving transport vehicles.
FHP is associated with neck and shoulder pain and temporomandibular joint dysfunction (incorrect alignment of the lower jaw to the skull) (Harman, Hubley-Kozey & Butler 2005). With FHP there is excessive anterior positioning of the head with increased curvature at the cervical spine and a rounding of the shoulders (see Figure 3). In addition to the musculoskeletal imbalance caused by FHP, this condition has also been linked to fatigue, restricted motion of the neck and chronic neck pain. Harman and colleagues demonstrated that an exercise program with strengthening exercises for the cervical flexors and shoulder retractors combined with stretching of the cervical extensor and pectoral muscles was most effective in helping to correct this posture problem.
Posture Concerns: Adolescents
Normally, as a child advances into adolescence (11–12 years) compressive forces on spinal intervertebral disks and facet joints are adequately balanced through ligamentous tension, allowing modest energy expenditure from postural muscles. However, structural or functional body stressors (e.g., tension, trauma, etc.) may prevent achievement of optimum posture.
Environmental factors that contribute to faulty posture include prolonged slouched sitting, ill-fitting school desks and overloaded bags and backpacks (Britnell et al. 2005). Growth spurts and discomfort with a changing body image may also predispose youth to body alignment disorders. According to Britnell, the most widespread posture deformity of adolescence is an idiopathic structural scoliosis (this is the most common type of scoliosis in adolescence, and it is much more common in females than males). Idiopathic structural scoliosis occurs in the thoracic region of the spine with convexity (or curvature) to the right side (when the body is viewed from behind). Given the complexity of the postural problems that can develop in adolescents, exercise professionals working to resolve these issues are well advised to collaborate with a physical therapist and/or primary health professional.
Posture Concerns: Adults (25–45 years)
Britnell et al. (2005) note that postural changes between ages 25 and 45 are no longer impacted by structural growth. However, sports activities and occupational behaviors (e.g., prolonged sitting, standing or stooping at work, heavy manual labor or repetitive movements) may contribute to posture adaptations, some of which may promote deviations from optimal posture. In addition, Britnell and colleagues note that high-risk social behaviors such as drug use and excessive drinking, as well as some fashion trends (e.g., high heels and restrictive clothing), may compromise muscle balance, movement patterns and joint positions. The authors state that these adult years are an ideal time to develop total-body and core-strengthening programs (as well as healthy lifestyle behaviors) that promote and maintain optimal posture.
Posture Concerns: Pregnancy and Postpartum
Britnell et al. (2005) state that numerous posture adaptations take place during pregnancy and postpartum. The changes are caused by retention of body fluid, an increase in body mass, and laxity in supporting joint structures (stemming from increased production of the hormone relaxin). Careful consideration must be taken in loading the spine. The authors add that pelvic pain and back pain are common problems during pregnancy. Some primary posture goals with this special population are core, pelvic-floor and balance-training exercises.
Posture Concerns: Older Individuals
Edmond et al. (2005), in a rather large study of 444 women (aged 72–96) who were part of the famous Framingham Study (a heart disease study originally composed of adults aged 30–62 from Framingham, Massachusetts), observed a number of limitations associated with (not caused by) poor posture. They included difficulty standing in one place for about 15 minutes; difficulty stooping, crouching and kneeling; difficulty getting in and out of a car; difficulty walking; difficulty putting on socks; difficulty reaching or extending arms above shoulder level; difficulty writing; and difficulty handling small objects. As observed by the authors, age-related musculoskeletal problems (e.g., osteoporosis) surely contributed to these findings. The two most notable limitations associated with declining posture, according to Edmond and colleagues, were difficulties pushing and pulling a large object, such as a living room chair.
Edmond et al. argue that this data is clear evidence that health professionals need to be proactive in developing interventions to minimize postural deviations and limitations. Britnell et al. (2005) propose that exercise programs need to focus on improving muscular fitness, balance, agility, range of motion and coordination for older clients. They specifically note that strength and agility training has been shown to meaningfully reduce the risk of falling in older women.
Good Posture Promotes Better Health
Enlighten clients that posture is an important consideration in all activities of daily living (e.g., walking, lifting objects, holding objects and driving) and that keeping good posture can make a considerable difference to the long-term health of the spine. Many postural problems are detectable at very early stages, regardless of age. If not corrected, these issues will become more pronounced.
Exercise professionals are in a leading position to correct spinal misalignments with a well-developed exercise program of flexibility, muscular strength, muscular endurance, agility and balance training. Educate your clients to adopt a new posture pleasure principle: planning and prevention precludes pain and promotes perfect posture.
A major factor in urinary incontinence in women is weak pelvic-floor muscles. Pelvic-floor exercises have proved successful for treating urinary incontinence (Britnell et al. 2005).