A study of the upper limb motion of patients with spinal cord injury while eating using two types of self-helping device

頸髄損傷者の食事動作に関して,スプーンの使用方法を替えることにより,上肢各関節(肩･肘・前腕・手関節)の角度と運動の範囲がどのように変化するかを明らかにするために,三次元動作解析を行った.対象はC6レベルの頸髄損傷者5人で,「ヨーグルトを食べる」という課題を2種類の自助具(自助具1:母指側使用,自助具2:手掌側使用)を用い実施した.撮影された画像から時間と上肢各関節角度を求め,自助具1,自助具2使用時で比較検討した.結果,自助具1使用時には自助具2使用時と比べ,1回の食事動作におけるすくう動作が占める割合が多い傾向にあった.また,食物をすくう際に肩関節屈曲,肩関節外転の運動が多く必要とされ,一連の動作を通じて前腕が回内方向に移行し,肩関節が屈曲・外転方向に移行することが明らかとなった.以上より,前腕の回外運動が十分可能である場合には手掌側使用の自助具の導入が望ましく,また母指側使用で食事を行う場合には,食物を口へ運ぶ動作だけでなく,すくう動作においても肩関節の運動が必要になることを十分に考慮した上で,自助具の提供やセッティングを行うことが重要であることが示唆された.The purpose of the present experiment was to examine how the upper limb movements (shoulder, elbow, forearm, wrist) of patients with spinal cord injury (C6 level) were affected while using two types (type 1: pronation type, type 2: supination type) of self-helping device. Five subjects were required to eat 5 spoonfuls of yoghurt. We recorded the position of 11 light reflecting markers attached to the subjects' body with three cameras. We divided the eating action into three phases, the scoop phase, reach-to-mouth phase, and reach-to-plate phase. These kinematic landmarks were used to define the dependent variables. We calculated five joint angles (shoulder flexion, shoulder abduction, elbow flexion, forearm supination, wrist extension) with a three-dimensional video-based motion analysis system (APAS System, Ariel Dynamics), and analyzed how they changed at each phase. We compared them while using type 1 and type 2. While using type 1, the scoop phase played a larger part than other phases, and shoulder flexion, shoulder abduction and elbow flexion angles increased, not only in the reach-to-mouth phase but also in the scoop phase, and the supination angle decreased. This result suggests that patients who can supinate their forearm had better use type 2, and also that it is important to consider upper limb movements in the scoop phase when we provide patients with a self-helping device. In this study, however, we focused only on upper limb movements. We also have to analyze head, neck and trunk movements and examine the relationship among upper limb, head, neck and trunk

Ipsilateral primary sensorimotor cortical response to mechanical tactile stimuli

We studied somatosensory-evoked fields elicited by mechanical versus electrical stimuli to index finger of healthy participants. Mechanical stimulation was index pulp compression and decompression by using nonmagnetic mechanical stimulator. Electrical stimulation was three times of sensory threshold and delivered to index pulp by using ball-shaped electrodes. Mechanical/electrical stimuli evoked contralateral primary somatosensory cortical responses in all respective participants. Compressive stimuli evoked ipsilateral primary sensorimotor cortical responses in all respective participants, with dipole strengths less than contralateral primary somatosensory cortical responses of compressive stimuli. Mechanical/electrical stimuli evoked secondary somatosensory (SII) cortical responses bilaterally; electrical-stimuli SII dipole strengths were relatively stronger than compressive-stimuli SII responses. It is concluded that the use of mechanical stimulation may improve our understanding of functional sensory cortical responses compared with electrical stimulation

Transcutaneous auricular vagus nerve stimulation enhances short-latency afferent inhibition via central cholinergic system activation

Abstract The present study examined the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on short-latency afferent inhibition (SAI), as indirect biomarker of cholinergic system activation. 24 healthy adults underwent intermittent taVNS (30 s on/30 s off, 30 min) or continuous taVNS at a frequency of 25 Hz (15 min) along with earlobe temporary stimulation (15 min or 30 min) were performed in random order. The efficiency with which the motor evoked potential from the abductor pollicis brevis muscle by transcranial magnetic stimulation was attenuated by the preceding median nerve conditioning stimulus was compared before taVNS, immediately after taVNS, and 15 min after taVNS. Continuous taVNS significantly increased SAI at 15 min post-stimulation compared to baseline. A positive correlation (Pearson coefficient = 0.563, p = 0.004) was observed between baseline SAI and changes after continuous taVNS. These results suggest that 15 min of continuous taVNS increases the activity of the cholinergic nervous system, as evidenced by the increase in SAI. In particular, the increase after taVNS was more pronounced in those with lower initial SAI. This study provides fundamental insight into the clinical potential of taVNS for cholinergic dysfunction

Three-dimensional motion analysis of pre- and postoperative thumb movement in trapeziometacarpal joint osteoarthritis-Comparison of arthrodesis and trapeziectomy with suspensionplasty.

Trapeziometacarpal osteoarthritis (TMC-OA) reduces the range of motion (ROM) of the thumb. However, the kinematic change achieved through surgical treatment remains unclear. Therefore, to quantify the kinematic change following TMC-OA surgery, we performed a three-dimensional motion analysis of the thumb using an optical motion capture system preoperatively and 1 year postoperatively in 23 patients with TMC-OA scheduled for arthrodesis (AD) or trapeziectomy with suspensionplasty (TS). Eighteen hands of nine healthy volunteers were also included as controls. Both procedures improved postoperative pain and Disability of the Arm, Shoulder and Hand scores, and AD increased pinch strength. The ROM of the base of the thumb was preserved in AD, which was thought to be due to the appearance of compensatory movements of adjacent joints even if the ROM of the TMC joint was lost. TS did not improve ROM. Quantifying thumb kinematic changes following TMC-OA surgery can improve our understanding of TMC-OA treatment and help select surgical procedures and postoperative assessment