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 .
Muscle tenderness and peak torque changes after downhill running following a prior bout of isokinetic eccentric exercise.
Unaccustomed exercise ( usually of an eccentric nature ) is often followed by delayed onset muscle soreness ( DOMS ) . Previous studies have found that prior eccentric activity produces a training effect which reduces DOMS and morphological changes . The aim of this study was to examine the effects of a prior bout of maximal isokinetic eccentric exercise on DOMS , strength loss and plasma creatine kinase ( CK ) changes following a downhill run . Ten male subjects with a mean ( + /- S.D. ) age of 22.5 + /- 2.8 years , body mass of 62.67 + /- 0.05 kg and height of 176 + /- 3 cm were allocated to either a treatment group or a control group . The treatment group performed 100 maximal eccentric activations of the knee extensors in the dominant leg at 0.52 rad s-1 . Two weeks later , the downhill run was performed on a motor-driven treadmill . This consisted of five bouts of 8 min at a gradient of -10 % at a speed corresponding to 80 % of the predicted maximal heart rate . The untrained group performed the downhill run as above but without the prior isokinetic session . Tenderness measurements , plasma CK activity and concentric and eccentric isokinetic peak torque measurements of the knee extensors at 0.52 and 2.83 rad s-1 were recorded prior to , immediately following and 2 , 4 and 7 days after each protocol . The isokinetic protocol caused an increase ( P < 0.01 ) in CK and tenderness and a decrease ( P < 0.05 ) in concentric and eccentric torque at both speeds in the treatment group . Following the downhill run , a reduction in peak torque ( P < 0.01 ) was observed in the eccentric and concentric modes at both isokinetic speeds in the control group . For the treatment group , the decrease in peak torque occurred only at the faster eccentric speed . With the exception of the faster eccentric speed , the decrement in peak torque was greater in the control group in all post-exercise isokinetic strength tests . There was less tenderness ( P < 0.01 ) in the trained knee extensor muscle group . Peak torque also returned to pre-downhill values earlier for the trained group . Although plasma CK activity increased in both groups after downhill running , it was much lower ( P < 0.01 ) in the trained group . The results suggest that a prior bout of isokinetic eccentric training reduces muscle damage , reduces the amount of strength loss and decreases the sensation of DOMS after downhill running
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 .