Groundhog Day or variety? Posture and exercise.
Does every day feel like Groundhog day, or am I just getting old?
Speaking of everyday being the same, variety is the key not only to the combat the Groundhog Day experience, but to posture and exercise as well. There is no one perfect posture for sitting, standing, sleeping or ANY exercise for that matter. We all have different and unique (and somewhat asymmetrical) anatomy as well physiology.
General guidelines are important for posture and exercise and there are postures (and exercise techniques) that are generally better than others, especially if held or moved for a long time (small force) or under a larger force or load (held or moved for a short time).
However, as we spend more time in one position or add repetitions to our exercise, our bodies develop strain reinforcements – neurologically at first, then through connective tissue enhancement to support those positions, loads and/or movements. These connective tissue adaptations can have short (and sometimes long) term advantages, but generally are not ideal over longer periods of time unless variety and full range of motion are implemented or maintained.
During exercise, neurologically adaptive and protective variations in our exercise technique/path/biomechanics occur on every repetition based on the safest joint (as well as muscle and tendon/connective tissue) position through feedback loops. This slight variation or change in joint angle/position and muscle recruitment occurs with every repetition because variables such as metabolic fatigue, microdamage, tissue temperature etc. change and therefore the load capacity of our joints and soft tissue change as the exercise continues. For example, marathon runners tend to lean more forward at the end of a marathon to maintain speed and offset the damage/weakness of the muscles (hips flexors etc.) that are (over) used in the early stages of the race.
In summary, if the variety of your postures, positions and movements are high throughout your day, the exact or perfect position (or ranges or motion) you are in, especially for shorter periods of time or under lesser loads, matters less.
A good rule of thumb is the heavier the load, the stricter your form, technique or posture should be. Otherwise embrace a variety of positions and techniques in posture, exercise and movement in general.
And of course, consult your Doctor, therapist, trainer etc. before you try anything.