scholarly journals Impaired sensorimotor control of the hand in congenital absence of functional muscle spindles

2018 ◽  
Vol 120 (6) ◽  
pp. 2788-2795 ◽  
Author(s):  
Lyndon J. Smith ◽  
Lucy Norcliffe-Kaufmann ◽  
Jose-Alberto Palma ◽  
Horacio Kaufmann ◽  
Vaughan G. Macefield
Keyword(s):  
Autonomic Neuropathy ◽  
Motor Performance ◽  
Large Diameter ◽  
Precision Grip ◽  
Muscle Spindles ◽  
Type Iii ◽  
Congenital Insensitivity ◽  
Tungsten Microelectrode ◽  
Muscles Of The Hand ◽  
Intrinsic Muscles

Patients with hereditary sensory and autonomic neuropathy type III (HSAN III) exhibit marked ataxia, including gait disturbances. We recently showed that functional muscle spindle afferents in the leg, recorded via intraneural microelectrodes inserted into the peroneal nerve, are absent in HSAN III, although large-diameter cutaneous afferents are intact. Moreover, there is a tight correlation between loss of proprioceptive acuity at the knee and the severity of gait impairment. We tested the hypothesis that manual motor performance is also compromised in HSAN III, attributed to the predicted absence of muscle spindles in the intrinsic muscles of the hand. Manual performance in the Purdue pegboard task was assessed in 12 individuals with HSAN III and 11 age-matched healthy controls. The mean (±SD) pegboard score (number of pins inserted in 30 s) was 8.1 ± 1.9 and 8.6 ± 1.8 for the left and right hand, respectively, significantly lower than the scores for the controls (15.0 ± 1.3 and 16.0 ± 1.1; P < 0.0001). Performance was not improved after kinesiology tape was applied over the joints of the hand. In 5 patients we inserted a tungsten microelectrode into the ulnar nerve at the wrist. No spontaneous or stretch-evoked muscle afferent activity could be identified in any of the 11 fascicles supplying intrinsic muscles of the hand, whereas touch-evoked activity from low-threshold cutaneous mechanoreceptor afferents could readily be recorded from 4 cutaneous fascicles. We conclude that functional muscle spindles are absent in the short muscles of the hand and most likely absent in the long finger flexors and extensors, and that this largely accounts for the poor manual motor performance in HSAN III. NEW & NOTEWORTHY We describe the impaired manual motor performance in patients with hereditary sensory and autonomic neuropathy type III (Riley-Day syndrome), who exhibit congenital insensitivity to pain, poor proprioception, and marked gait ataxia. We show that functional muscle spindles are absent in the intrinsic muscles of the hand, which we argue contributes to their poor performance in a task involving the precision grip.

scholarly journals Firing properties of muscle spindles supplying the intrinsic foot muscles of humans in unloaded and freestanding conditions

2019 ◽  
Vol 121 (1) ◽  
pp. 74-84 ◽  
Author(s):  
T. P. Knellwolf ◽  
A. R. Burton ◽  
E. Hammam ◽  
V. G. Macefield
Keyword(s):  
Muscle Spindle ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Muscle Spindles ◽  
Medial Malleolus ◽  
Proprioceptive Information ◽  
Muscle Spindle Afferents ◽  
Tungsten Microelectrode ◽  
Firing Properties ◽  
Intrinsic Muscles

We recently developed an approach for recording from muscle spindles in the intrinsic muscles of the foot in freestanding humans by inserting a tungsten microelectrode into the posterior tibial nerve behind the medial malleolus of the ankle. Here we characterize the behavior of muscle spindles in the small muscles of the foot in 1) seated subjects with the leg horizontal and the foot naturally plantarflexed and 2) standing subjects. In the first study, recordings were made from 26 muscle spindle afferents located within flexor digiti minimi brevis ( n = 4), abductor digiti minimi ( n = 3), quadratus plantae ( n = 3), plantar interossei ( n = 4), flexor digitorum brevis ( n = 3), dorsal interossei ( n = 2), and lumbricals ( n = 2), with one each supplying abductor hallucis, adductor hallucis, and flexor hallucis brevis. The identity of another two muscle afferents was unknown. The majority of the units were silent at rest, only seven (27%) being spontaneously active. Because of the anatomic constraints of the foot, some spindles supplying muscles acting on the toes responded to movements of one or more digits. In the second study, 12 muscle spindle afferents were examined during standing. The ongoing discharge of eight spindle afferents covaried with changes in the center of pressure during postural sway. We conclude that the majority of spindle endings in the small muscles of the foot are silent at rest, which may allow them to encode changes in conformation of the foot when it is loaded during standing. Moreover, these muscle spindle afferents can provide useful proprioceptive information during standing and postural sway. NEW & NOTEWORTHY We have characterized the firing properties of muscle spindles in the intrinsic muscles of the human foot for the first time. The majority of the spindle endings are silent in seated subjects, and most fire tonically during standing, their discharge covarying with center of pressure during postural sway. We conclude that spindle endings in the intrinsic muscles of the foot provide useful proprioceptive information during free standing.

scholarly journals Microneurography from the posterior tibial nerve: a novel method of recording activity from the foot in freely standing humans

2018 ◽  
Vol 120 (3) ◽  
pp. 953-959 ◽  
Author(s):  
T. P. Knellwolf ◽  
A. R. Burton ◽  
E. Hammam ◽  
V. G. Macefield
Keyword(s):  
Tibial Nerve ◽  
Human Subjects ◽  
Muscle Spindles ◽  
Cutaneous Afferents ◽  
Medial Malleolus ◽  
Posterior Tibial Nerve ◽  
Posterior Tibial ◽  
Novel Approach ◽  
Tungsten Microelectrode ◽  
Intrinsic Muscles

The posterior tibial nerve, located behind the medial malleolus of the ankle, supplies the intrinsic muscles of the foot and most of the skin of the sole. We describe a novel approach for recording from this nerve via a percutaneously inserted tungsten microelectrode and provide examples of recordings from presumed muscle spindle endings recorded in freely standing human subjects. The fact that the angular excursions of the ankle joint are small as the foot is loaded during the transition from the seated position to standing means that one can obtain stable recordings of neural traffic in unloaded, loaded, and freely standing conditions. We conclude that this novel approach will allow studies that will increase our understanding of the roles of muscle and cutaneous afferents in the foot in the control of upright posture. NEW & NOTEWORTHY We have performed the first microneurographic studies from the posterior tibial nerve at the ankle. Stability of the recording site allows one to record from muscle spindles in the intrinsic muscles of the foot as well as from cutaneous mechanoreceptors in the sole of the foot during the transition from seated to standing. This novel approach opens up new opportunities for studying the roles of muscle and cutaneous afferents in the foot in the control of upright stance.

A COMPARISON OF THE STRENGTH OF THE ABDUCTION OF THE LITTLE AND INDEX FINGERS AND PALMAR ABDUCTION AND OPPOSITION OF THE THUMB BETWEEN COLLEGE BASEBALL PLAYERS AND INEXPERIENCED SPORTS PLAYERS

2010 ◽  
Vol 13 (02) ◽  
pp. 75-82 ◽  
Author(s):  
Takako Chikenji ◽  
Hajime Toda ◽  
Chin Gyoku ◽  
Naoki Oikawa ◽  
Masaki Katayose ◽  
...  
Keyword(s):  
Statistical Difference ◽  
Index Finger ◽  
Baseball Players ◽  
Intrinsic Muscle ◽  
Batting Performance ◽  
College Baseball ◽  
Muscle Groups ◽  
Muscles Of The Hand ◽  
Intrinsic Muscles ◽  
Little Finger

The purpose of this study was to investigate the strengths of four intrinsic muscles of the hand of college baseball players. The strengths of four intrinsic muscle groups were measured by the Rotterdam Intrinsic Hand Myometer (RIHM) which has been developed to assess the abduction of the little finger and index finger, and palmar abduction and opposition of the thumb. The strengths of these four intrinsic muscle groups were compared between baseball players and inexperienced sports players. The abduction of the little finger and index finger, and the opposition of the thumb in both the dominant and nondominant hands of the baseball players were notably stronger than those of the inexperienced sports players. There was no statistical difference in the strength of the palmar abduction of the thumb between the two groups. The results suggest that the specific intrinsic muscles in both the dominant and nondominant hands might be strengthened by repeated baseball practices, such as a batting performance, which requires strain in both the dominant and nondominant hands repeatedly.

The Early Development of Muscle Spindles in the Rat

1973 ◽  
Vol 12 (1) ◽  
pp. 175-195
Author(s):  
ALICE MILBURN
Keyword(s):  
Close Association ◽  
Large Diameter ◽  
Muscle Spindles ◽  
Muscle Fibres ◽  
Intrafusal Muscle ◽  
Intrafusal Fibres ◽  
Fusimotor Innervation ◽  
Nuclear Chain ◽  
Intramuscular Nerve

The morphogenesis of muscle spindles in rat lower hind-limb muscles has been investigated using the electron microscope. The earliest detectable spindles are seen in the 19.5-day foetus and consist of a single myotube bearing simple nerve terminals of the large primary afferent axon from nearby unmyelinated intramuscular nerve trunks. The capsule forms by an extension of the perineural epithelium of the supplying nerve fasciculus, and is confined initially to the innervated zone. Myonuclei accumulate in this region, so that the first intrafusal muscle fibre to develop is a nuclear-bag fibre. Myoblasts, present within the capsule of the spindle throughout its development, fuse to form a smaller less-differentiated myotube by the 20-day foetal stage. This new myotube matures by close association with the initial fibre, and by birth (21-22 days gestation) has formed the smaller, intermediate bag fibre, that has been identified histochemically and ultrastructurally in the adult. The nuclear-chain fibres develop in the same way; myoblasts fuse to form satellite myotubes that mature in pseudopodial apposition to one of the other fibres within its basement membrane. This apposition consists of extensions of sarcoplasm from the developing myotube into the supporting fibre. By the 4-day postnatal stage the full adult complement of 4 intrafusal muscle fibres is present, although ultrastructural variations, seen in the adult, are not differentiated. The fusimotor innervation begins to arrive at birth, but is not mature until the 12th postnatal day, when the myofibrillar ultrastructural differentiation, including the loss of the M-line in the large-diameter bag fibre, is complete. The periaxial space appears at the same time. It is suggested that the sequential development of the intrafusal fibres is a reflexion of the decreasing morphogenetic effect of the afferent innervation, whereas the role of the fusimotor innervation is in ultrastructural, myofibrillar differentiation.

scholarly journals Refractory Myositis Affecting the Intrinsic Muscles of the Hand

2020 ◽  
Vol 59 (9) ◽  
pp. 1211-1214
Author(s):  
Kosei Nakamura ◽  
Akihiro Sugai ◽  
Etsuji Saji ◽  
Kensaku Kasuga ◽  
Osamu Onodera
Keyword(s):  
Muscles Of The Hand ◽  
Intrinsic Muscles
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