Rehabilitation effect in balance and strength after anterior cruciate ligament reconstruction

The object of research: anterior cruciate ligament. The research problem: the anterior cruciate ligament injuries are one of the most common knee injuries (Muscolo et al., 2010). They are vulnerable 30 times more often than posterior ones (Streckis ir kt., 2007). Knee joint kinematics changes because of these injuries, which may be the cause of the degeneration of joint surface, even if the injury is just a few millimeters (Guess & Stylianou, 2012). It is important to analyze the specifics of injuries, possible causes, mechanisms, rehabilitation effects for knee function, to assess the effect for muscle strength, functional capacity, balance (Dai et al., 2012) after anterior cruciate ligament reconstructive surgery. Based on the analysis of the literature, we pose the following hypothesis: suffered a anterior cruciate ligament injuries decreased shin stretching and buckling muscles strength, will not change balance fluctuations by taking test with two legs and opened eyes, but will make it worse with closed eyes. A. F. Hamilton et al. (2004) found that unevenness size of nerve impulse transmission is lower in large muscles than in small muscles while transmitting nerve signals. That is why we pose one more hypothesis that after injuries shin stretching and buckling muscles balance stability depends on visual feedback information and efforts level, and having balance test with closed eyes it is harder to manage developed power of agonist – antagonists (Vaillancourt et al., 2001; Guigon et al., 2008). After the rehabilitation all the above changes should improve. Aim of the study – to determine the impact of rehabilitation for knee function and to assess the effect for muscle strength, functional capacity, balance after anterior cruciate ligament reconstructive surgery. Tasks of the study: 1. To determine shank stretching and buckling muscles strength and balance before reconstructive anterior cruciate ligament surgery. 2. To assess shank stretching and buckling muscles strength and balance after reconstructive anterior cruciate ligament surgery. 3. To compare both legs shanks buckling muscles strength and balance after rehabilitation. 4. To assess rehabilitation effect for muscular strength, functional capacity, balance. The methods and organization of research: The research was conducted in 2014 – 2015 period in Lithuanian Sport University, in Sport Science and Innovation institute laboratory. Rehabilitation has been used in several institutions: in “Rolandas Žeimys sport club” and “Impuls” sport and health club. Rehabilitation was started two weeks after surgery, during which subjects were treated in outpatient settings. Rehabilitation was applied twice a week for three months. One session lasts for 45 minutes. The research included 10 physically active men suffered anterior cruciate ligament injuries. Balance has been tested while standing on both legs with eyes closed, eyes open, on healthy and traumatized leg. The maximum forceful power moment (MVC) is evaluated by three muscles power testing angular speed - 60°/s, 180°/s, 300°/s. Tests has been taken before anterior cruciate ligament reconstructive surgery and 1,2,3 months after. Conclusions: 1. Before ACL reconstructive surgery damaged leg stretching and buckling muscles strength was lower than healthy leg muscles strength (p<0,05), though it did not influence balance fluctuation by making test with two legs and opened eyes, but balance with closed eyes was worse. 2. 1, 2, 3 months after ACL reconstructive surgery the strength of damage leg’s shank stretching muscles statistically was lower, but healthy leg muscles strength statistically did not change. After rehabilitation program operated leg muscle strength remained lower than healthy leg muscles power. 1, 2, 3 months after ACL reconstructive surgery fluctuation speed was statistically lower by standing with opened eyes on a both legs than standing with closed eyes (p<0,05). 3. Comparing with initial states stretching muscles strength of damaged leg shank decreased at all three angular rates (p<0,05). Examination of the fluctuations speed of standing on both legs with closed eyes showed that after the rehabilitation program statistically decreased speed of these fluctuations comparing with initial states, while the total trajectory of length fluctuations did not change significantly. 4. It was found that after ACL injury rehabilitation the strength of damaged shank stretching and buckling muscles stays lower than healthy leg muscles strength; muscular strength ratio (H:Q) before and 1, 2, 3 months after surgery at three angular rates is statistically significant (p