Patterns of muscle activity for digital coarticulation

The Journal of Physiology

Uehara

Sakamoto

et al. 2018

Self Cite

Focal task-specific dystonia (FTSD) compromises dexterous movements. A proposed pathophysiological mechanism of FTSD involves malfunction of the motor cortex (M1). However, no evidence is yet available regarding whether and how malfunctions of M1 are responsible for the loss of motor dexterity. Here, we addressed this issue by assessing both M1 excitability and detailed movement parameters, as well as their relationships. Transcranial magnetic stimulation was applied over M1 in 20 pianists with FTSD, 20 healthy pianists and 20 non-musicians. The patients demonstrated both reduced short-interval intracortical inhibition (SICI) and elevated intracortical facilitation (ICF) compared with the healthy controls. This indicates that the abnormal cortical excitability reflects pathophysiology but not current skills. Hand motor dexterity was evaluated by position sensors during piano playing at two tempi. The patients showed delayed transition from finger flexion to extension at the fastest tempo and greater timing variability of the finger movements. Furthermore, multivariate analyses identified distinct sets of covariation between cortical excitability and dexterity measures. Namely, the SICI measure and ICF measure were associated with the temporal variability of the movements and the quickness of the transition from flexion to extension, respectively. Specifically, the reduced inhibition and elevated facilitation at M1 in pianists was related to the temporal imprecision and impairment of quick transitions in the sequential finger movements. The present study provides novel evidence associating M1 malfunctions with dexterity loss.

Section: Discussionmentioning

confidence: 99%

Aberrant cortical excitability reflects the loss of hand dexterity in musician's dystonia

The Journal of Physiology

Uehara

Sakamoto

et al. 2018

Self Cite

“…For example, the fingers and wrist initiated preparatory motions 500 ms prior to the thumb-under maneuver, which facilitated the subsequent horizontal translation of the hand. Finger muscular activity also provided evidence supportive for co-articulation in piano playing (Winges et al, 2013). The balance of burst amplitudes across multiple muscles depended on the characteristics of the preceding and subsequent keypresses, forming neuromuscular co-articulation throughout the time course of sequential finger movements.…”

Section: Hand Motor Control In Piano Playingmentioning

confidence: 93%

Flexibility of movement organization in piano performance

Altenmüller

2013

Front. Hum. Neurosci.

Self Cite

Piano performance involves a large repertoire of highly skilled movements. The acquisition of these exceptional skills despite innate neural and biomechanical constraints requires a sophisticated interaction between plasticity of the neural system and organization of a redundant number of degrees of freedom (DOF) in the motor system. Neuroplasticity subserving virtuosity of pianists has been documented in neuroimaging studies investigating effects of long-term piano training on structure and function of the cortical and subcortical regions. By contrast, recent behavioral studies have advanced the understanding of neuromuscular strategies and biomechanical principles behind the movement organization that enables skilled piano performance. Here we review the motor control and biomechanics literature, introducing the importance of describing motor behaviors not only for understanding mechanisms responsible for skillful motor actions in piano playing, but also for advancing diagnosis and rehabilitation of movement disorders caused by extensive piano practice.

“…This can be attributed to a less pronounced difference in the cortical activity associated with the index and ring fingers for musicians compared with non-musicians (Slobounov et al, 2002), anatomical changes that can lower biomechanical constraint on individual fingers in musicians (Smahel and Klimová 2004), or motor cortical reorganization due to musical training (Gentner et al 2010). The skilled pianists also reduced coactivation of the finger flexor and extensor muscles (Winges et al 2013), which can lower muscular stiffness and thereby decrease spillover of force exerted by one muscle into the adjacent muscles. This is because when one finger moves, lower stiffness at multi-tendon muscle results in production of smaller elastic force at its adjacent fingers, which eventually weakens the biomechanical constraint across fingers (Lang and Schieber 2004).…”

Section: Discussionmentioning

confidence: 99%

“…Jerde et al, 2003; Santello and Soechting, 1998; Soechting and Flanders, 1997; Weiss and Flanders, 2004). Patterns of coarticulation have also been observed where elements within a sequence are influenced by the preceding and subsequent elements (Engel et al, 1997; Jerde et al, 2003; Winges et al, 2013). The task itself influences the expected patterns of covariation and coarticulation.…”

Section: Introductionmentioning

confidence: 96%

Distinct digit kinematics by professional and amateur pianists

Winges

2015

Neuroscience

Many everyday tasks such as typing, grasping, and object manipulation require coordination of dynamic movement across multiple joints and digits. Playing a musical instrument is also one such task where the precise movement of multiple digits is transformed into specific sounds defined by the instrument. Through extensive practice musicians are able to produce precisely controlled movements to interact with the instrument and produce specific sequences of sounds. The present study aimed to determine what aspects of these dynamic movement patterns differ between pianists who have achieved professional status compared to amateur pianists that have also trained extensively. Common patterns of movement for each digit strike were observed for both professional and amateur pianists that were sequence specific, i.e. influenced by the digit performing the preceding strike. However, group differences were found in multi-digit movement patterns for sequences involving the ring or little finger. In some sequences, amateur subjects tended to work against the innate connectivity between digits while professionals allowed slight movement at non-striking digits (covariation) which was a more economical strategy. In other sequences professionals used more individuated finger movements for performance. Thus the present study provided evidence in favor of enhancement of both movement covariation and individuation across fingers in more skilled musicians, depending on fingering and movement sequence.