Conclusion Overall , our findings do not support the presence of a secondary loss of strength following an acute muscle injury , and strongly suggest that strength , on average , recovers steadily over the first 3 days post-injury
Background An immediate loss of strength follows virtually all types of muscle injury but there is debate whether the initial strength loss is maximal or if a secondary loss of strength occurs during the first 3 days post-injury .
Objective The objective of this analysis was to conduct a systematic review and meta- analysis of the research literature to determine if a secondary loss of strength occurs after an injurious initiating event .
Impact of muscle length during stretch-shortening contractions on real-time and temporal muscle performance measures in rats in vivo.
The objective of the present study was to investigate the impact of muscle length during stretch-shortening cycles on static and dynamic muscle performance . Animals were r and omly assigned to an  isometric ( control , Con , n = 12 ) , a  short-muscle-length ( S-Inj , 1.22 - 2.09 rad , n = 12 ) , or a long-muscle-length ( L-Inj , 1.57 - 2.44 rad , n = 12 ) group . The dorsiflexor muscles were exposed in vivo to 7 sets of 10 stretch-shortening contractions ( conducted at 8.72 rad/s ) or 7 sets of isometric contractions of the same stimulation duration by using a custom- design ed dynamometer . Performance was characterized by multipositional isometric exertions and positive , negative , and net work before exposure , 6 h after exposure , and 48 h after exposure to contractions . Real-time muscle performance during the stretch-shortening cycles was characterized by stretch-shortening parameters and negative , positive , and net work . The S-Inj group recovery ( force difference ) was similar to the Con group force difference at 48 h , whereas the L-Inj group force difference was statistically greater at 1.39 , 1.57 , and 1.74 rad than the Con group force difference ( P < 0.05 ) . Negative work ( P < 0.05 ) and net work ( P < 0.05 ) were statistically lower in the S-Inj and L-Inj groups than in the Con group 48 h after exposure to contractions . Of the real-time parameters , there was a difference in cyclic force with treatment during the stretch-shortening cycles ( P < 0.0001 ) , with the L-Inj group being the most affected . Thus longer ranges of motion result in a more profound isometric force decrement 48 h after exposure to contractions and in real-time changes in eccentric forces
Conclusion Overall , our findings do not support the presence of a secondary loss of strength following an acute muscle injury , and strongly suggest that strength , on average , recovers steadily over the first 3 days post-injury
Background An immediate loss of strength follows virtually all types of muscle injury but there is debate whether the initial strength loss is maximal or if a secondary loss of strength occurs during the first 3 days post-injury .
Objective The objective of this analysis was to conduct a systematic review and meta- analysis of the research literature to determine if a secondary loss of strength occurs after an injurious initiating event .