Relationship between Movement Quality, Functional Ambulation Status, and Spatiotemporal Gait Parameters in Children with Myelomeningocele.

AIMS: We investigated relationships among the Pediatric Neuromuscular Recovery Scale (Peds NRS), modified Hoffer Scale, and spatiotemporal gait parameters in children with myelomeningocele (MMC). METHODS: 21 children with MMC, age 5.3 years (SD = 2.6), were assessed by three clinicians using the Peds NRS and modified Hoffer Scale. In eight children, gait parameters were also measured. RESULTS: The Peds NRS summary score demonstrated good correlation with modified Hoffer Scale score (r = -0.64, p = 0.002) that accounted for 41% of variation in summary score. Six Peds NRS seated/standing items exhibited good relationships with modified Hoffer Scale (r = -0.51 to -0.70, p ≤ 0.023), and the sit-to-stand item demonstrated an excellent relationship (r = -0.85, p < 0.001). Sit-to-stand and three standing/walking items exhibited excellent associations with cadence (Rs = 0.81 to 0.88, p ≤ 0.014), and swing and stance time (both Rs = -0.83 to -0.90, p ≤ 0.01). Two Peds NRS standing items and modified Hoffer Scale score demonstrated good correlations with velocity (Rs = 0.71, p = 0.047; Rs = -0.73, p = 0.04, respectively). CONCLUSIONS: Our findings suggest that children with MMC who exhibit greater movement quality and trunk control are likely to be functional ambulators with more optimal spatiotemporal gait parameters.

Temporal Indices of Ankle Clonus and Relationship to Electrophysiologic and Clinical Measures in Persons With Spinal Cord Injury.

BACKGROUND AND PURPOSE: Clonus arising from plantar flexor hyperreflexia is a phenomenon that is commonly observed in persons with spastic hypertonia. We assessed the temporal components of a biomechanical measure to quantify ankle clonus, and validated these in persons with spasticity due to spinal cord injury. METHODS: In 40 individuals with chronic (>1 year) spinal cord injury, we elicited ankle clonus using a standardized mechanical perturbation (drop test). We examined reliability and construct validity of 2 components of the drop test: clonus duration (timed with a stopwatch) and number of oscillations in the first 10-second interval (measured via optical motion capture). We compared these measures to the Spinal Cord Assessment Tool for Spastic reflexes (SCATS) clonus score and H-reflex/M-wave (H/M) ratio, a clinical and electrophysiologic measure, respectively. RESULTS: Intra- and interrater reliability of clonus duration measurement was good [intraclass correlation coefficient, ICC (2, 1) = 1.00]; test-retest reliability was good both at 1 hour [ICC (2, 2) = 0.99] and at 1 week [ICC (2, 2) = 0.99]. Clonus duration was moderately correlated with SCATS clonus score (r = 0.58). Number of oscillations had good within-session test-retest reliability [ICC (2, 1) > 0.90] and strong correlations with SCATS clonus score (r = 0.86) and soleus H/M ratio (r = 0.77). DISCUSSION AND CONCLUSIONS: Clonus duration and number of oscillations as measured with a standardized test are reliable and valid measures of plantar flexor hyperreflexia that are accessible for clinical use. Tools for objective measurement of ankle clonus are valuable for assessing effectiveness of interventions directed at normalizing reflex activity associated with spasticity.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A179).

Modulatory effects of locomotor training on extensor spasticity in individuals with motor-incomplete spinal cord injury.

PURPOSE: Sparse data exist about effects of locomotor training on spasticity in individuals with spinal cord injury (SCI). We investigated changes in spastic responses in individuals with motor-incomplete SCI (MISCI) associated with locomotor training and examined properties of a biomechanical measure of clonus severity, plantar flexor reflex threshold angle (PF RTA). METHODS: In 18 individuals with chronic MISCI, we assessed biomechanical and electrophysiologic measures of extensor spasticity and their relationship with walking speed before and after 12 weeks of body-weight supported locomotor training. Measures included PF RTA, plantar flexor (ankle clonus) and quadriceps spasm duration, soleus H-reflex, and ankle muscle electromyography. PF RTA validity was assessed by measuring PF RTA and clonus duration in 40 individuals with SCI and 10 non-disabled individuals. RESULTS: Locomotor training was associated with decreased PF RTA (p = 0.06), ankle clonus (p = 0.09) and quadriceps spasm (p = 0.05). PF RTA discriminated between non-disabled individuals and individuals with SCI and was moderately correlated with walking speed, soleus H/M ratio, and quadriceps spasm duration. CONCLUSIONS: In persons with spastic paresis due to MISCI, locomotor training was associated with decreased spasticity as measured by decreased plantar flexor excitability, ankle clonus, and quadriceps spasm.

Operant conditioning to increase ankle control or decrease reflex excitability improves reflex modulation and walking function in chronic spinal cord injury.

Ankle clonus is common after spinal cord injury (SCI) and is attributed to loss of supraspinally mediated inhibition of soleus stretch reflexes and maladaptive reorganization of spinal reflex pathways. The maladaptive reorganization underlying ankle clonus is associated with other abnormalities, such as coactivation and reciprocal facilitation of tibialis anterior (TA) and soleus (SOL), which contribute to impaired walking ability in individuals with motor-incomplete SCI. Operant conditioning can increase muscle activation and decrease stretch reflexes in individuals with SCI. We compared two operant conditioning-based interventions in individuals with ankle clonus and impaired walking ability due to SCI. Training included either voluntary TA activation (TA↑) to enhance supraspinal drive or SOL H-reflex suppression (SOL↓) to modulate reflex pathways at the spinal cord level. We measured clonus duration, plantar flexor reflex threshold angle, timed toe tapping, dorsiflexion (DF) active range of motion, lower extremity motor scores (LEMS), walking foot clearance, speed and distance, SOL H-reflex amplitude modulation as an index of reciprocal inhibition, presynaptic inhibition, low-frequency depression, and SOL-to-TA clonus coactivation ratio. TA↑ decreased plantar flexor reflex threshold angle (-4.33°) and DF active range-of-motion angle (-4.32°) and increased LEMS of DF (+0.8 points), total LEMS of the training leg (+2.2 points), and nontraining leg (+0.8 points), and increased walking foot clearance (+ 4.8 mm) and distance (+12.09 m). SOL↓ decreased SOL-to-TA coactivation ratio (-0.21), increased nontraining leg LEMS (+1.8 points), walking speed (+0.02 m/s), and distance (+6.25 m). In sum, we found increased voluntary control associated with TA↑ outcomes and decreased reflex excitability associated with SOL↓ outcomes.

Restoration of walking function in an individual with chronic complete (AIS A) spinal cord injury.

OBJECTIVE: The prognosis for further recovery of motor function 2 years after complete spinal cord injury is poor. This case report describes recovery of walking function in an a 33-year old man two years post T7 spinal cord injury American Spinal Injury Association Impairment Scale A following intensive physical therapy and robotic locomotor training. DESIGN: Case report. METHODS: The subject engaged in an intensive clinic-based physical therapy program and research-based robotic locomotor training study over a 7-month period. Physical therapy was initiated 4 months prior to entry into the research study, and targeted trunk control, upper extremity strength, and upright mobility. On initial entry into the robotic locomotor training study the subject's AIS A classification was substantiated. Initial, interim, and follow-up tests of sensation, strength, sitting balance, spasticity, and mobility were performed. RESULTS: Lower extremity motor scores improved from 0/50 to 4/50, bilateral hip flexors increased from grade 0/5 to 2/5, warranting injury re-classification from American Spinal Injury Association Impairment Scale A to C. Intensive physical therapy combined with robotic locomotor training was associated with restoration of short distance walking function with lower extremity braces and a walker. CONCLUSION: To our knowledge, this is the first report of an individual with chronic spinal cord injury American Spinal Injury Association Impairment Scale A improving in over-ground walking ability following intensive physical therapy and robotic locomotor training. The presence of a neurophysiologically discomplete lesion probably permitted training of operational neural pathways and enabled the development of useful voluntary movement.