Abstract des Autors

Osteoarthritis is one of the most common musculoskeletal diseases in older adults (Guccione at al., 1994) and is often followed by pain and muscle weakness (Petterson et al., 2011). For the knee joint, total knee arthroplasty (TKA) is a successful intervention to reduce pain and improve activity limitations (Mizner et al., 2005). However, shortly after surgery quadriceps strength is remarkably weaker compared to pre-operative condition or to the non-involved leg (Mizner et al., 2005). While differences between pre- and post-operative conditions can be compensated for after six months, discrepancies between legs tend to remain (Mizner et al., 2005). Additionally, the quadriceps cross-sectional area of the involved leg is significantly smaller before (15%), four weeks (22%), 12 weeks (15%), and one year (7%) after TKA compared to the non-involved leg (Petterson et al., 2011). Therefore, even one year after TKA a consistent side-to-side asymmetry is visible and can impair daily activities (Maffiuletti et al., 2010). Together with the risk of sarcopenia, these adverse developments are important reasons for keeping an active lifestyle after surgery in an ageing population. Previous publications have shown that loading of the m. quadriceps femoris during recreational skiing is an effective stimulus to increase muscle mass (Narici et al., 2011) and strength (Müller et al., 2011) in healthy older individuals. Therefore, we hypothesized that this kind of intervention would mitigate the loss of muscle mass and strength associated with ageing and disuse and reduce the side-to-side asymmetry in older TKA patients.