الفهرس 
Title : Effects of Swimming and Stretching Initiation Time on the Healing of Strain-Induced Muscle Injury in Rats
Abstractيوجد فقط 14 صفحة متاحة للعرض العام
 |  | from | 76 |  |  |
| | | from | 76 | | |
المستخلص
Swimming and stretching are recommended for muscle strain rehabilitation. Yet, the effect of combining these two modalities on tissue healing is unclear. Purpose: to investigate whether the time of initiating swimming and stretching exercises would affect the healing of Tibialis Anterior (TA) muscle induced-strain in rats. Animals and Methods: Forty healthy male adult Wistar rats weighing 225 ±15 grams were randomly and equally divided into five groups; a normal control group (GI); an injured untreated control (GII); and three treated injured groups that either received stretching and swimming exercises at the acute stage (GIII), or swimming at the acute stage followed by stretching at the sub-acute stage (GIV), or stretching and swimming simultaneously starting from the sub-acute stage (GV). All injured animals had the TA muscle strain induced using a valid non-invasive method. In each session, static passive manual stretching was applied for 30 seconds for 4 times, whereas swimming was given for 45 minutes. Treatment was applied daily for a total of 8 consecutive days. Afterwards, all animals were left free to move within their cages without any further intervention until euthanasia at the 21st day (chronic stage). All groups were functionally assessed post treatment using sciatic functional index (SFI). After animals were sacrificed, TA was harvested and prepared for histopathological scoring using the semi-quantitative modified Movin score. This scoring system assesses fiber structure, arrangement, cell nuclei, collagen stainability, cellularity, vascularity and hyalinization. Each variable is scored from 0 (normal) to 3 (severe changes); with a total possible score ranging from 0 (normal tendon) to 21 (severe tendinopathy). Two blind independent assessors graded stained sections twice using a standard protocol. After consensus, the final score was used for further statistical analyses. Between-group comparison was done using Kruskal-Wallis test followed by Mann-Whitney test, with the significance level set at P<0.05. Results: Compared to normal control (GI), injured untreated control (G II) had a significantly worse tissue score (P=0.008), whereas all treated animal groups (GIII, IV and V) were not different (P > 0.05) indicating restoration of normal tissue appearance. Compared to GII, treated groups GIII and IV showed significant improvement (P=0.032 and 0.008, respectively), confirming the effectiveness of the therapeutic intervention, whereas, animals that received treatment at the subacute stage (GV) were not different (P=0.171). Function as measured by SFI scores was not significantly different between all study groups (P=0.690). Conclusions: Initiating stretching and swimming from the acute and through the subacute stages of strain injury improves tissue healing, whereas depriving animals from exercising during the acute stage is not the optimum choice for tissue healing. On the other hand, in this model, functional recovery is not affected by exercise initiation time. Future studies are recommended to investigate the effectiveness of different therapeutic exercises combination on the long term.