Hi Bruno,
Your therapist is basically telling you that you have problems with your posture and as a result certain muscles are too tight, and others are not tight enough.
Upper Crossed Syndrome is when your shoulders roll forwards, which sometimes causes the elbows to rotate outwards. There is often tightness in the chest (Pectoralis Major, Pectoralis Minor, and the Anterior Deltoids), and weakness or overstretching in the back (mid-trapezius and rhomboids). Turning out of the elbows indicates that the Latissimus Dorsi muscles are tight.
If this is the case then the chest, lats, and front of the shoudlers need stretching and the mid back needs strengthening.
Upper crossed syndrome is becoming ever more common with the use of computers, poor positioning when sitting, and increasing time spent slumped on the sofa watching tv!
Lower Crossed Syndrome is also very common, and occurs when the pelvis is tipped forwards (called an anterior tilt) - this is best described if you imagine looking at someone side-on, and imagine their pelvis as a bucket. In normal good posture, the bucket should be near upright, but in lower crossed syndrome the bucket tilts forwards so that the water in the bucket would pour out over the feet.
This can be quite unflattering (or perhaps flattering depending on your opinions on the derrier!).
The muscles which need stretching in this condition are the hip flexors and lower back, and the muscles that need to be strengthened are the Gluteals (yes, the bottom!) and the abdominals.
I hope this is of some help to you, please feel free to contact me if you would like further information.
Ruth Cheesley BSc(Hons) MSc MCSP
Chartered Physiotherapist