مقايسه مولفه هاي نيروي عكس العمل زمين طي دويدن در كودكان داراي عارضه سربه جلو در مقايسه با همسالان سالم

Running Ground Reaction Force Characteristics in Children with Forward Head Posture Compared to Healthy Control Ones

مقدمه و اهداف عارضه سربه­ جلو يكي از اختلالات شايع در ناحيه گردن است. هدف مطالعه حاضر بررسي مولفه­ هاي نيروي عكس ­العمل زمين در كودكان داراي عارضه سربه­ جلو در مقايسه با همتايان سالم طي فاز اتكاي دويدن بود. مواد و روش ­ها 28 كودك پسر به ترتيب در دو گروه سالم (تعداد=16 نفر) و سربه­ جلو (تعداد=12 نفر) قرار گرفتند. دو سيستم صفحه ­نيرو كيستلر جهت ثبت نيروهاي عكس ­العمل زمين طي دويدن با پاي برهنه استفاده شد. اوج مولفه ­هاي نيروي عكس ­العمل زمين، زمان رسيدن به اوج اين مولفه ­ها، ايمپالس در سه بعد و اوج مثبت و منفي گشتاور آزاد جهت تحليل ­هاي بيشتر مورد محاسبه قرار گرفت. از آزمون آماري تي مستقل جهت مقايسه بين گروهي استفاده شد. سطح معناداري برابر 0/05>P بود. يافته ­ها نتايج نشان داد كه سرعت دويدن در كودكان داراي عارضه سرب­ جلو در مقايسه با گروه كنترل كمتر مي­باشد (0/001>P). زمان رسيدن اوج عمودي (حدود 11/2 درصد، اندازه اثر متوسط، 0/035=P) و خارجي (حدود 76/3 درصد، اندازه اثر بزرگ، 0/009=P) نيروي عكس­ العمل زمين در گروه سربه­ جلو نسبت گروه سالم بزرگتر بود. اوج مولفه ­هاي نيروي عكس ­العمل زمين و اوج مثبت و منفي گشتاور آزاد بين دو گروه به لحاظ آماري اختلاف معناداري را نشان نداد (0/05

Background and Aims: Forward head posture is one of the most prevalent disorders in the cervical area. The objective of the present study was to investigate ground reaction force components during running in an able-bodied control group and in children with forward head posture. Materials and Methods: A total of 28 male children including 16 healthy controls and 16 children with forward head posture participated in the current study. Two Kistler force platforms were used to record the ground reaction forces during barefoot running. Peak ground reaction force components, their time to peak, impulses in all axes, and peak positive and negative free moments were assessed. Independent sample t-test was used for between-group comparisons. The significance level was set at p<0.05. Results: The findings indicated that running speed in children with forward head was smaller than that in control group (P<0.001). Time to peak for vertical (by 11.2%; medium effect size; P=0.035) and lateral (by 76.3%; large effect size; P=0.009) ground reaction force components in forward head group were greater than those in healthy group. Peak ground reaction force components and peak positive and negative free moment amplitudes were not found to be statistically different between the two groups (P>0.05). Conclusion: Running speed in children with forward head posture was lower than that in healthy control group, while the peak ground reaction force components were similar to those in control group. This altered running speed and ground reaction forces are suggestive of a lower mechanical efficiency of running in children with forward head posture. Children with forward head posture need interventions such as sport exercises to reduce peak ground reaction force components and free moment values during running.