As shown in the current study, the results imply that vibration stimulation may be more favorably used to enhance the clinical function of the affected upper limb in patients with poststroke hemiparesis with improved spatiotemporal acuity during the forward-reaching task. A possible explanation for the observed gains with vibration stimulation may be that the facilitation of the firing of muscle spindle’s Ia afferents results in enhancement of corticospinal excitability and causes increased activity of the Ia inhibitory interneurons. As a result, the reflex threshold of the paretic limb is progressively reduced (Libouton et al., 2012), thereby leading to optimization of the control mechanism of muscular coactivation during actual limb movements (Trumbower et al., 2010). The present study supports the results of a previous study suggesting the beneficial long-term effects of a focal muscle vibration, which is applied repeatedly at a frequency of 100 Hz for 90 min over 3 consecutive days, on motor performance in patients with poststroke hemiparesis (Caliandro et al., 2012). In addition, the current results are similar to those of recent studies that reported positive changes in motor control during functional tasks (Liepert and Binder, 2010).
Muscle vibration provides additional opportunity for strong proprioceptive stimulation by reaching the sensorimotor cortex directly (Christova et al., 2011) and facilitating cortical reorganization, which can improve cortical influence on motor systems (Zhao et al., 2011). Recruitment of cortical neurons is probably because of the integration of somatosensory inputs, which facilitates the planning process of limb movements and regulates the potential involvement of adjacent joints. Moreover, another assumption of vibration effects is caused by repetitive tactile stimulation on skin, which results in benefits from synchronous activation in neural afferents and cortical neurons and influences the connectivity of cortical neurons in the sensory cortex with the neural network of other cortices (Freyer et al., 2012). After vibration stimulation, increased cortical excitability has been evidenced by numerous neuroscientific studies (Conrad et al., 2011). Such a neurophysiological correlation may be the possible mechanism for long-term potentiation derived from alterations in the strength of the corticocortical connections (Hoogendam et al., 2010). Enhanced cortical activity of the motor area may be a contributing factor to enhance the fidelity of movement control during the initial phase of rehabilitation such as the feedforward mechanism and anticipatory motor control. Subsequently, spinal reflex systems may be effectively modulated by facilitation in descending cortical control (Conrad et al., 2011). The reinforcement of cortical activation contributes toward the increase in motor-evoked potential and decrease in latency of the vibrated muscle, which is observed early after the onset of the vibration (Christova et al., 2011). These results suggest that our findings may be useful for research that investigates the effects of vibration on the recovery of somatosensory deficits and improvement of function after treatment, although a single application of sensory stimulation cannot affect brain plasticity.
In addition, a changed muscular response derived from the vibration stimulation can alter the spastic property of upper limb muscles (Zhao et al., 2011). Knowledge of these mechanisms may be useful for performing vibration stimulation as a daily routine therapy of stroke rehabilitation. In general, fine motor control and hand dexterity are the primary means of successfully executing skillful, voluntary movements, which is based on the ability to accept, precisely perceive, and discriminate sensory stimuli received from external environmental sources. Improved hand function may be the main factor allowing the ability to independently perform everyday tasks, leading to a huge impact on the quality of life (Carey et al., 1993). Therefore, the implication is that the use of sensory training contributes toward the transfer of its effects to daily, routine activities and functional recovery.
There are no conflicts of interest.
Alt Murphy M, Willén C, Sunnerhagen KS (2011). Kinematic variables quantifying upper-extremity performance after stroke
during reaching and drinking from a glass. Neurorehabil Neural Repair 25:71–80.
Blank R, von Kries R, Hesse S, von Voss H (2008). Conductive education for children with cerebral palsy: effects on hand motor functions relevant to activities of daily living. Arch Phys Med Rehabil 89:251–259.
Brasil-Neto JP, de Lima AC (2008). Sensory deficits in the unaffected hand of hemiparetic stroke
patients. Cogn Behav Neurol 21:202–205.
Caliandro P, Celletti C, Padua L, Minciotti I, Russo G, Granata G, et al. (2012). Focal muscle vibration in the treatment of upper limb spasticity: a pilot randomized controlled trial in patients with chronic stroke
. Arch Phys Med Rehabil 93:1656–1661.
Carey LM, Matyas TA, Oke LE (1993). Sensory loss in stroke
patients: effective training of tactile and proprioceptive discrimination. Arch Phys Med Rehabil 74:602–611.
Carr JH, Shepherd RB (1998). Neurological rehabilitation: optimizing motor performance. London: Churchill Livingstone.
Chen HM, Chen CC, Hsueh IP, Huang SL, Hsieh CL (2009). Test-retest reproducibility and smallest real difference of 5 hand function
tests in patients with stroke
. Neurorehabil Neural Repair 23:435–440.
Chen WL, Shih YC, Chi CF (2010). Hand and finger dexterity as a function of skin temperature, EMG, and ambient condition. Hum Factors 52:426–440.
Christova M, Rafolt D, Golaszewski S, Gallasch E (2011). Outlasting corticomotor excitability changes induced by 25 Hz whole-hand mechanical stimulation. Eur J Appl Physiol 111:3051–3059.
Connell LA, Lincoln NB, Radford KA (2008). Somatosensory impairment after stroke
: frequency of different deficits and their recovery. Clin Rehabil 22:758–767.
Conrad MO, Scheidt RA, Schmit BD (2011). Effects of wrist tendon vibration on targeted upper-arm movements in poststroke hemiparesis. Neurorehabil Neural Repair 25:61–70.
Doucet BM, Griffin L (2013). High-versus low-frequency stimulation effects on fine motor control in chronic hemiplegia: a pilot study. Top Stroke
Freyer F, Reinacher M, Nolte G, Dinse HR, Ritter P (2012). Repetitive tactile stimulation changes resting-state functional connectivity-implications for treatment of sensorimotor decline. Front Hum Neurosci 6:144.
Folstein MF, Folstein SE, McHugh PR (1975). “Minimental state”. A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 12:189–198.
Hoogendam JM, Ramakers GM, Di Lazzaro V (2010). Physiology of repetitive transcranial magnetic stimulation of the human brain. Brain Stimul 3:95–118.
Ikuno K, Kawaguchi S, Kitabeppu S, Kitaura M, Tokuhisa K, Morimoto S, et al. (2012). Effects of peripheral sensory nerve stimulation plus task-oriented training on upper extremity function in patients with subacute stroke
: a pilot randomized crossover trial. Clin Rehabil 26:999–1009.
Jeannerod M, Arbib MA, Rizzolatti G, Sakata H (1995). Grasping objects: the cortical mechanisms of visuomotor transformation. Trends Neurosci 18:314–320.
Jebsen RH, Taylor N, Trieschmann RB, Trotter MJ, Howard LA (1969). An objective and standardized test of hand function
. Arch Phys Med Rehabil 50:311–319.
Kalisch T, Tegenthoff M, Dinse HR (2010). Repetitive electric stimulation elicits enduring improvement of sensorimotor performance in seniors. Neural Plast 2010:690531.
Kawahira K, Shimodozono M, Etoh S, Kamada K, Noma T, Tanaka N (2010). Effects of intensive repetition of a new facilitation technique on motor functional recovery of the hemiplegic upper limb and hand. Brain Inj 24:1202–1213.
Kwon YH, Jang SH (2011). The enhanced cortical activation induced by transcranial direct current stimulation during hand movements. Neurosci Lett 492:105–108.
Laaksonen K, Kirveskari E, Mäkelä JP, Kaste M, Mustanoja S, Nummenmaa L, et al. (2012). Effect of afferent input on motor cortex excitability during stroke
recovery. Clin Neurophysiol 123:2429–2436.
Libouton X, Barbier O, Berger Y, Plaghki L, Thonnard JL (2012). Tactile roughness discrimination of the finger pad relies primarily on vibration sensitive afferents not necessarily located in the hand. Behav Brain Res 229:273–279.
Liepert J, Binder C (2010). Vibration-induced effects in stroke
patients with spastic hemiparesis – a pilot study. Restor Neurol Neurosci 28:729–735.
Michielsen ME, Selles RW, van der Geest JN, Eckhardt M, Yavuzer G, Stam HJ, et al. (2011). Motor recovery and cortical reorganization after mirror therapy in chronic stroke
patients: a phase II randomized controlled trial. Neurorehabil Neural Repair 25:223–233.
Overvliet KE, Anema HA, Brenner E, Dijkerman HC, Smeets JB (2011). Relative finger position influences whether you can localize tactile stimuli. Exp Brain Res 208:245–255.
Platz T, Pinkowski C, van Wijck F, Kim IH, di Bella P, Johnson G (2005). Reliability and validity of arm function assessment with standardized guidelines for the Fugl-Meyer Test, Action Research Arm Test and Box and Block Test: a multicentre study. Clin Rehabil 19:404–411.
Pouydebat E, Fragaszy D, Kivell TL (2014). Grasping in primates: for feeding, moving and human specificities. BMSAP 26:129–133.
Roberts HC, Denison HJ, Martin HJ, Patel HP, Syddall H, Cooper C, Sayer AA (2011). A review of the measurement of grip strength in clinical and epidemiological studies: towards a standardised approach. Age Ageing 40:423–429.
Roiha K, Kirveskari E, Kaste M, Mustanoja S, Mäkelä JP, Salonen O, et al. (2011). Reorganization of the primary somatosensory cortex during stroke
recovery. Clin Neurophysiol 122:339–345.
Rood MS (1954). Neurophysiologic reaction as a basis for physical therapy. Phys Ther Rev 34:444–449.
Rothwell JC, Traub MM, Day BL, Obeso JA, Thomas PK, Marsden CD (1982). Manual motor performance in a deafferented man. Brain 105 (Pt 3):515–542.
Scalha TB, Miyasaki E, Lima NM, Borges G (2011). Correlations between motor and sensory functions in upper limb chronic hemiparetics after stroke
. Arq Neuropsiquiatr 69:624–629.
Seo NJ, Rymer WZ, Kamper DG (2010). Altered digit force direction during pinch grip following stroke
. Exp Brain Res 202:891–901.
Sesto ME, Radwin RG, Salvi FJ (2003). Functional deficits in carpal tunnel syndrome. Am J Ind Med 44:133–140.
Trombly CA, Radomski MV (2002). Occupational therapy for physical dysfunction, 5th ed. Baltimore: Lippincott Williams & Wilkins.
Trumbower RD, Ravichandran VJ, Krutky MA, Perreault EJ (2010). Contributions of altered stretch reflex coordination to arm impairments following stroke
. J Neurophysiol 104:3612–3624.
Van den Berg FE, Swinnen SP, Wenderoth N (2010). Hemispheric asymmetries of the premotor cortex are task specific as revealed by disruptive TMS during bimanual versus unimanual movements. Cereb Cortex 20:2842–2851.
Wang L, Yu C, Chen H, Qin W, He Y, Fan F, et al. (2010). Dynamic functional reorganization of the motor execution network after stroke
. Brain 133 (Pt 4):1224–1238.
Yousef H, Boukallel M, Althoefer K (2011). Tactile sensing for dexterous in-hand manipulation in robotics – a review. Sensors Actuators A: Physical 167:171–187.
Zhao X, Fan X, Song X, Shi L (2011). Daily muscle vibration amelioration of neural impairments of the soleus muscle during 2 weeks of immobilization. J Electromyogr Kinesiol 21:1017–1022.