Unilateral reference values for Hoffmann’s amplitude could be applied to the diagnosis of lumbosacral radiculopathy, especially in patients with bilateral lesions. Here, we assessed Hoffmann’s reflex by measuring H-...Unilateral reference values for Hoffmann’s amplitude could be applied to the diagnosis of lumbosacral radiculopathy, especially in patients with bilateral lesions. Here, we assessed Hoffmann’s reflex by measuring H-wave amplitude and the ratio of H-wave amplitude to M-wave amplitude (the H/M ratio). We performed a cross-sectional survey of patients from a Taiwan rehabilitation center (n = 64, age 20 - 87) who presented with lower back pain that radiated to the leg and received a referral for electrodiagnostic examinations. Reference values for H-wave profile parameters were determined using data from lumbosacral radiculopathy-negative patients (n = 10, age 22 - 53), who had normal big toe test results, ankle reflex test results, motor and sensory nerve conductive studies and F-wave latency and who displayed no evidence of radiculopathy in electromyography and imaging studies. The 50th percentile values for H/M ratio and H-wave amplitude were 28% and 6.25 mV, respectively. An H-wave profile th percentile (H/M ratio bosacral radiculopathy (n = 64). Approximately 41% of patients with an H-wave profile th percentile showed electromyography-confirmed chronic radiculopathy. Electromyography-confirmed current radiculopathy was observed in 35% of patients with an H/R展开更多
Background:Acute lateral ankle sprains(ALAS)are associated with long-term impairments and instability tied to altered neural excitability.Arthrogenic muscle inhibition(AMI)has been observed in this population;however,...Background:Acute lateral ankle sprains(ALAS)are associated with long-term impairments and instability tied to altered neural excitability.Arthrogenic muscle inhibition(AMI)has been observed in this population;however,relationships with injury-related impairments are unclear,potentially due to the resting,prone position in which AMI is typically measured.Assessing AMI during bipedal stance may provide a better understanding of this relationship.Methods:AMI was assessed in 38 young adults(19 ALAS within 72 h of injury:10 males,21.4±2.7 years;19 healthy controls:10 males,21.9±2.2 years;mean±SD)using the Hoffmann reflex(H-reflex)during bipedal stance.Electrical stimulation was administered to identify the _(max)imal H-reflex(H_(max))and _(max)imal motor response(M_(max))from the soleus,fibularis longus,and tibialis anterior muscles.The primary outcome measure was the H_(max)/M_(max) ratio.Secondary outcomes included acute symptoms(pain and swelling),postural control during bipedal stance,and self-reported function.Results:No significant group-by-limb interactions were observed for any muscle.However,a significant group main effect was observed in the soleus muscle(F(1,35)=6.82,p=0.013),indicating significantly lower H_(max)/M_(max) ratios following ALAS(0.38±0.20)compared to healthy controls(0.53±0.16).Furthermore,lower H_(max)/M_(max) ratios in the soleus significantly correlated with acute symptoms and self-reported function but not with postural control.Conclusion:This study supports previous evidence of AMI in patients with ALAS,providing insight into neurophysiologic impacts of musculoskeletal injury.Our results suggest that assessing AMI in a standing position following acute injury may provide valuable insight into how AMI develops and guide potential therapeutic options to curb and offset the formation of joint instability.展开更多
BACKGROUND： Previous studies have demonstrated the relationship of lower limb dominance with left- and right-handedness, supporting findings suggest that there is a role for peripheral factors in the neural control o...BACKGROUND： Previous studies have demonstrated the relationship of lower limb dominance with left- and right-handedness, supporting findings suggest that there is a role for peripheral factors in the neural control of movement. OBJECTIVE： To investigate the effect of laterality pattern on the neural mechanisms of motor control at the peripheral level. DESIGN, TIME AND SETTING： A controlled observation experiment was performed at the Motor Diagnostics Laboratory of the Academy of Physical Education in Katowice, Poland, in June 2009. PARTICIPANTS： Twenty young male adults aged 21-23 years and presenting two laterality patterns in hand-foot combination （right handed-right footed and left handed-left footed groups） took part in the experiment. All participants were carefully screened to eliminate any neurological or muscle disease or trauma. METHODS： The experiment included a laterality evaluation and the motor evoked potentials of dominant and non-dominant limbs. Measures were done through the use of the Hoffmann-reflex （H-reflex） circuitry. The soleus H-reflex parameters elicited at rest in lower extremities were compared. The soleus H-reflex and the direct motor response were elicited in lower extremities of each participant in the same laboratory session. MAIN OUTCOME MEASURES： Onset latencies and min-max amplitudes of the direct motor response and the H-reflex; the motor and sensory conduction velocities; and symmetry coefficients of response parameters. RESULTS： The analysis of symmetry coefficients of direct and late motor responses confirmed differences between two laterality patterns in amplitude and latency of the H-reflex as well as in a sensory conduction velocity （P 〈 0.05）, but not in direct motor response parameters. The amplitude of the H-reflex and the calculated sensory la afferent conduction velocity in the dominant lower extremity were significantly depressed in the right-sided group in comparison to the left-sided group （P = 0.001）. The right-sided group presented significantly higher motor fiber conduction velocity in the dominant leg than in the non-dominant leg （P = 0.006）, with no similar effect in the left-sided group. CONCLUSION： The neural control of the H-reflex elicited at rest is related to the laterality pattern in hand-foot combination in healthy adults. This result strongly suggests the possible existence of intrinsic control mechanisms of afferent feedback related to functional dominance in human limbs.展开更多
文摘Unilateral reference values for Hoffmann’s amplitude could be applied to the diagnosis of lumbosacral radiculopathy, especially in patients with bilateral lesions. Here, we assessed Hoffmann’s reflex by measuring H-wave amplitude and the ratio of H-wave amplitude to M-wave amplitude (the H/M ratio). We performed a cross-sectional survey of patients from a Taiwan rehabilitation center (n = 64, age 20 - 87) who presented with lower back pain that radiated to the leg and received a referral for electrodiagnostic examinations. Reference values for H-wave profile parameters were determined using data from lumbosacral radiculopathy-negative patients (n = 10, age 22 - 53), who had normal big toe test results, ankle reflex test results, motor and sensory nerve conductive studies and F-wave latency and who displayed no evidence of radiculopathy in electromyography and imaging studies. The 50th percentile values for H/M ratio and H-wave amplitude were 28% and 6.25 mV, respectively. An H-wave profile th percentile (H/M ratio bosacral radiculopathy (n = 64). Approximately 41% of patients with an H-wave profile th percentile showed electromyography-confirmed chronic radiculopathy. Electromyography-confirmed current radiculopathy was observed in 35% of patients with an H/R
文摘Background:Acute lateral ankle sprains(ALAS)are associated with long-term impairments and instability tied to altered neural excitability.Arthrogenic muscle inhibition(AMI)has been observed in this population;however,relationships with injury-related impairments are unclear,potentially due to the resting,prone position in which AMI is typically measured.Assessing AMI during bipedal stance may provide a better understanding of this relationship.Methods:AMI was assessed in 38 young adults(19 ALAS within 72 h of injury:10 males,21.4±2.7 years;19 healthy controls:10 males,21.9±2.2 years;mean±SD)using the Hoffmann reflex(H-reflex)during bipedal stance.Electrical stimulation was administered to identify the _(max)imal H-reflex(H_(max))and _(max)imal motor response(M_(max))from the soleus,fibularis longus,and tibialis anterior muscles.The primary outcome measure was the H_(max)/M_(max) ratio.Secondary outcomes included acute symptoms(pain and swelling),postural control during bipedal stance,and self-reported function.Results:No significant group-by-limb interactions were observed for any muscle.However,a significant group main effect was observed in the soleus muscle(F(1,35)=6.82,p=0.013),indicating significantly lower H_(max)/M_(max) ratios following ALAS(0.38±0.20)compared to healthy controls(0.53±0.16).Furthermore,lower H_(max)/M_(max) ratios in the soleus significantly correlated with acute symptoms and self-reported function but not with postural control.Conclusion:This study supports previous evidence of AMI in patients with ALAS,providing insight into neurophysiologic impacts of musculoskeletal injury.Our results suggest that assessing AMI in a standing position following acute injury may provide valuable insight into how AMI develops and guide potential therapeutic options to curb and offset the formation of joint instability.
基金a Grant from the Ministry of Science and Higher Education of Poland, No. N 404 045 31/2332
文摘BACKGROUND： Previous studies have demonstrated the relationship of lower limb dominance with left- and right-handedness, supporting findings suggest that there is a role for peripheral factors in the neural control of movement. OBJECTIVE： To investigate the effect of laterality pattern on the neural mechanisms of motor control at the peripheral level. DESIGN, TIME AND SETTING： A controlled observation experiment was performed at the Motor Diagnostics Laboratory of the Academy of Physical Education in Katowice, Poland, in June 2009. PARTICIPANTS： Twenty young male adults aged 21-23 years and presenting two laterality patterns in hand-foot combination （right handed-right footed and left handed-left footed groups） took part in the experiment. All participants were carefully screened to eliminate any neurological or muscle disease or trauma. METHODS： The experiment included a laterality evaluation and the motor evoked potentials of dominant and non-dominant limbs. Measures were done through the use of the Hoffmann-reflex （H-reflex） circuitry. The soleus H-reflex parameters elicited at rest in lower extremities were compared. The soleus H-reflex and the direct motor response were elicited in lower extremities of each participant in the same laboratory session. MAIN OUTCOME MEASURES： Onset latencies and min-max amplitudes of the direct motor response and the H-reflex; the motor and sensory conduction velocities; and symmetry coefficients of response parameters. RESULTS： The analysis of symmetry coefficients of direct and late motor responses confirmed differences between two laterality patterns in amplitude and latency of the H-reflex as well as in a sensory conduction velocity （P 〈 0.05）, but not in direct motor response parameters. The amplitude of the H-reflex and the calculated sensory la afferent conduction velocity in the dominant lower extremity were significantly depressed in the right-sided group in comparison to the left-sided group （P = 0.001）. The right-sided group presented significantly higher motor fiber conduction velocity in the dominant leg than in the non-dominant leg （P = 0.006）, with no similar effect in the left-sided group. CONCLUSION： The neural control of the H-reflex elicited at rest is related to the laterality pattern in hand-foot combination in healthy adults. This result strongly suggests the possible existence of intrinsic control mechanisms of afferent feedback related to functional dominance in human limbs.
