Clinical term

Musculoskeletal disorders (MSDs)

Musculoskeletal disorders (MSDs) are conditions of the locomotor system affecting muscles, tendons, nerves and periarticular structures, favored in particular by exertion, awkward postures, repetitive movements and work organization.

Scientific basis

MSDs present mainly as pain, stiffness, loss of strength or sensory disturbances. They mostly affect the upper limbs (neck, shoulders, elbows, wrists) but also the back, particularly the lumbar region.

Their risk factors are biomechanical (exertion, awkward or sustained postures, repetitiveness), psychosocial (work intensity, time pressure, low autonomy) and environmental (vibration, cold).

Blue Portance / SBNFA™ reading

In the SBNFA™, an MSD is not read solely as the consequence of “bad posture.” The analysis also looks at the way a load is applied: its intensity; its duration; its repetition; its low variability; the system's ability to redistribute it.

A moderate load maintained for a long time without variation can thus place sustained demands on the same areas. The SBNFA™ therefore shifts the question from posture to adaptive potential: what matters is not only the position held, but the system's capacity to change it in order to redistribute what it receives.

Contribution to the analysis of sitting

Prolonged sitting is a work situation in which posture can remain largely unchanged for hours. Seating analysis is therefore not limited to the seat's adjustments: it also looks at what the seat leaves possible for shifting support points, mobilizing the pelvis and hips, and regularly changing configuration.

Not to be confused with

Low back pain, which refers to pain in a specific location and may or may not be an MSD; occupational disease, which is a medico-administrative status, not a diagnosis.

Related terms

Low back pain

Sources and scope

Established definition and occupational health data (INRS). This entry does not make it possible to attribute an individual's pain to an occupational cause.