title: Whole-body vibration-induced muscular reflex: Is it a stretch-induced reflex?
abstract: [Purpose] Whole-body vibration (WBV) can induce reflex responses in muscles. A number of studies have reported that the physiological mechanisms underlying this type of reflex activity can be explained by reference to a stretch-induced reflex. Thus, the primary objective of this study was to test whether the WBV-induced muscular reflex (WBV-IMR) can be explained as a stretch-induced reflex. [Subjects and Methods] The present study assessed 20 healthy males using surface electrodes placed on their right soleus muscle. The latency of the tendon reflex (T-reflex) as a stretch-induced reflex was compared with the reflex latency of the WBV-IMR. In addition, simulations were performed at 25, 30, 35, 40, 45, and 50 Hz to determine the stretch frequency of the muscle during WBV. [Results] WBV-IMR latency (40.5 ± 0.8 ms; 95% confidence interval [CI]: 39.0-41.9 ms) was significantly longer than T-reflex latency (34.6 ± 0.5 ms; 95% CI: 33.6-35.5 ms) and the mean difference was 6.2 ms (95% CI of the difference: 4.7-7.7 ms). The simulations performed in the present study demonstrated that the frequency of the stretch signal would be twice the frequency of the vibration. [Conclusion] These findings do not support the notion that WBV-IMR can be explained by reference to a stretch-induced reflex.
authors: Institute of Biomedical Engineering, Fatih University, Turkey.
authors: Halil Ibrahim
authors: HI
authors: Cakar
authors: Deparment of Physical Medicine and Rehabilitation, Bagcilar Training and Research Hospital, Turkey.
authors: Muharrem
authors: M
authors: Cidem
authors: Koç University School of Medicine, Turkey.
authors: Oguz
authors: O
authors: Sebik
authors: Koç University School of Medicine, Turkey.
authors: Gizem
authors: G
authors: Yilmaz
authors: Deparment of Physical Medicine and Rehabilitation, Cerrahpasa Medical Faculty, Istanbul University, Turkey.
authors: Safak Sahir
authors: SS
authors: Karamehmetoglu
authors: Institute of Biomedical Engineering, Fatih University, Turkey.
authors: Sadik
authors: S
authors: Kara
authors: Deparment of Physical Medicine and Rehabilitation, Bagcilar Training and Research Hospital, Turkey.
authors: Ilhan
authors: I
authors: Karacan
authors: Koç University School of Medicine, Turkey.
authors: Kemal Sıtkı
authors: KS
authors: Türker
keywords: Gravitational physiology; Skeletal muscle function; Tonic vibration reflex