Background and Purpose: Walking in the home and community is an important goal for individuals with incomplete spinal cord injury (iSCI). Walking in the community requires various skills, such as negotiating curbs, doors, and uneven terrain. This case report describes the use of a method to retrain walking overground that is intensive, variable, and relevant to daily walking (skill training). The aims of this case series were to determine the effectiveness of skill training in a small group of people with iSCI and to compare skill training with body-weight–supported treadmill training (BWSTT) in the same individuals.Case Description: Four individuals who were a median of 2.7 years (interquartile range [IQR]=12.8) after iSCI participated in alternating phases of intervention, each 3 months long. All patients started with BWSTT. Two patients subsequently engaged in skill training while the other 2 patients engaged in BWSTT, after which a third phase of intervention (opposite to the second) was repeated.Outcomes: The Modified Emory Functional Ambulation Profile, the 10-Meter Walk Test, the 6-Minute Walk Test, the Berg Balance Scale, and the Activities-specific Balance Confidence Scale were administered before training, monthly throughout training, and 3 months after training.Discussion: Overall improvements in walking speed met or exceeded the minimal clinically important difference for individuals with iSCI (≥0.05 m/s), particularly during the skill training phase (skill training: median=0.09 m/s, IQR=0.13; BWSTT: median=0.01 m/s, IQR=0.07). Walking endurance, obstacle clearance, and stair climbing also improved with both types of intervention. Three of the 4 patients had retained their gains at follow-up (retention of walking speed: median=92%, IQR=63%). Thus, the findings suggest that skill training was effective in this small group of individuals.

1. It was hypothesized that passive movement of either the whole leg or its separate segments, in a manner mimicking human gait, leads to attenuation of the soleus H reflex. It was further hypothesized that this attenuation arises from presynaptic effects. Reflex amplitudes were observed in humans during natural bipedal and unipedal stepping on the spot, during passive stepping, during passive movement of the lower limb segments about the hip, knee, and ankle individually in a stepping fashion, and during passive movement with tonic contraction of the soleus muscle. 2. In natural stepping at a cadence of 54 steps/min, the reflex means were substantially depressed in the swing phase (P < 0.01). (Means, standing control 90.1%, unipedal 8.3%, bipedal 6.9%, of maximum M wave.) During the stance phase, reflex magnitudes were mildly and significantly elevated in four of six subjects, compared with standing controls (P < 0.05). 3. For passive stepping, subjects were dorsally tilted 20 and 90 degrees (lying supine) from the vertical position, to obtain quiet electromyograms (EMGs) in the postural muscles. Recorded during natural stepping, the right leg was manipulated to match the electrogoniometer traces of the three major joints. 4. At 20 degrees of tilt of the body, mean H reflexes were significantly lower, by 26.4%, compared with the supine position (P < 0.05). During passive stepping movement of the leg at 54 steps/min, the reflex was profoundly attenuated over the entire cycle (P < 0.01). The significantly attenuated reflexes during active stepping and during passive stepping movement of the whole leg were not significantly different at the point where the limb approached full flexion in the swing phase (P > 0.48). This was the case for measurements made at either body position, 20 degrees dorsal tilt or supine. 5. Passive flexion-extension, around either the hip or the knee, significantly inhibited the mean reflex magnitude close to full flexion, at either body position (P < 0.01). Such movement around the ankle resulted in significant inhibition of the reflex in two of the four subjects (P < 0.05). The numeric sum of the reflex depression arising from the flexion-extension of the individual joints was greater than that arising from movement of the whole limb. 6. With the ankle braced, the significant reflex attenuation remained when a tonic isometric contraction of the soleus muscle was introduced. This suggests premotoneuronal mechanisms for the inhibition.(ABSTRACT TRUNCATED AT 400 WORDS)

1 To quantify the importance of reflexes due to muscle length changes in generating force during walking, we studied high decerebrate cats that walked on a treadmill. One leg was denervated except for the triceps surae and a few other selected muscles. The triceps surae muscles are ankle extensor muscles that attach to the Achilles' tendon which was cut and connected to a muscle puller. In some steps the EMG activity triggered the puller to move the muscle through the pattern of length changes that are normally produced by ankle movements in intact cats walking over ground (simulated walking). In other steps the muscles were held isometrically. The EMG and force produced during the two types of steps were compared. On average about 50% more EMG was generated during the E2 part of the simulated stance phase in the triceps surae muscles, but not in other muscles studied. 2 Force was increased significantly over the entire stance phase by about 20%, when muscle stretches simulating walking were applied. However, during much of the stance phase the triceps surae muscles are shortening and so would produce less force. The effect of shortening was assessed in control experiments in which these muscles were stimulated at a constant frequency, either isometrically or during simulated walking movements. 3 By combining data from the walking and control experiments, we estimate that about 35 % of the force produced in the cat ankle extensors during stance is produced by reflexes due to muscle length changes. Other sensory inputs may also contribute to force production, but the total reflex contribution will vary under different conditions of speed, length, loading, task difficulty, etc. Since a substantial percentage of the force in the stance phase of walking is normally produced by muscle reflexes, this force can be continuously adjusted up or down, if the muscles receive extra stretch or unloading during a particular step cycle.