Differential serial sarcomere number adaptations in knee extensor muscles of rats is contraction type dependent.

نویسندگان

  • Timothy A Butterfield
  • Timothy R Leonard
  • Walter Herzog
چکیده

Sarcomerogenesis, or the addition of sarcomeres in series within a fiber, has a profound impact on the performance of a muscle by increasing its contractile velocity and power. Sarcomerogenesis may provide a beneficial adaptation to prevent injury when a muscle consistently works at long lengths, accounting for the repeated-bout effect. The association between eccentric exercise, sarcomerogenesis and the repeated-bout effect has been proposed to depend on damage, where regeneration allows sarcomeres to work at shorter lengths for a given muscle-tendon unit length. To gain additional insight into this phenomenon, we measured fiber dynamics directly in the vastus lateralis (VL) muscle of rats during uphill and downhill walking, and we measured serial sarcomere number in the VL and vastus intermedius (VI) after chronic training on either a decline or incline grade. We found that the knee extensor muscles of uphill walking rats undergo repeated active concentric contractions, and therefore they suffer no contraction-induced injury. Conversely, the knee extensor muscles during downhill walking undergo repeated active eccentric contractions. Serial sarcomere numbers change differently for the uphill and downhill exercise groups, and for the VL and VI muscles. Short muscle lengths for uphill concentric-biased contractions result in a loss of serial sarcomeres, and long muscle lengths for downhill eccentric-biased contractions result in a gain of serial sarcomeres.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Sarcomere number regulation maintained after immobilization in desmin-null mouse skeletal muscle.

The serial sarcomere number of skeletal muscle changes in response to chronic length perturbation. The role of the intermediate filament desmin in regulating these changes was investigated by comparing the architectural adaptations of the tibialis anterior, extensor digitorum longus (EDL) and soleus from wild-type mice with those of homozygous desmin knockout mice after hindlimb immobilization....

متن کامل

The Comparison of Isokinetic Parameters of Hip and Knee Joint Muscles in Professional Soccer Players with Athletic Groin Pain and Healthy One: Implications for Sports Injuries Prevention

Aims and background: This study aimed to investigate the comparison of isokinetic parameters of hip and knee joint muscles in professional soccer players with athletic groin pain (AGP) and healthy ones. Material and Methods: 32 soccer players (control group (n=16) and AGP group (n=16)) who take part in the first and second division league participated in this study. The isokinetic dynamometer ...

متن کامل

The Effect of Kinesio Taping on Electromyography Activity and Co-Contraction of knee Muscles in People with Patellofemoral Pain Syndrome during climbing and descending stairs

Introduction and aim: Ascending and descending stairs are one of the challenging activities for people with patellofemoral pain syndrome. Kinesiotype is one of the rehabilitation methods to improve the symptoms of patellofemoral pain syndrome.  This study aimed to evaluate the effect of kinesiotype on electromyographic activity and co-contraction of knee muscles in patients with patellofemoral ...

متن کامل

Effect of Exercise Therapy with Medicine Ball on Directed and General Co-contraction of Knee Joint Muscles in Low Back Pain Patients During Walking

Background and Objectives: Low back pain is a musculoskeletal disorder with an annual prevalence of 18.6%. The aim of the present study was to evaluate the effect of rehabilitation with medicine ball on directed and general co-contraction of knee joint muscles in low back patients during walking, Materials and Methods: The present study was a clinical trial. The statistical population of the p...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Journal of applied physiology

دوره 99 4  شماره 

صفحات  -

تاریخ انتشار 2005