Tibialis posterior transfer in central palsy of foot levators: A propos of 17 cases

Tibialis posterior transfer in central palsy of foot levators: a propos of 17cases.AimTo evaluate, in spastic patients with a lack of tibialis anterior spontaneous contraction, the efficiency of the tibialis posterior transfer and the occurrence of adverse effects on the static foot posture.Patients and methodsSeventeen patients were evaluated retrospectively, on average 69months after intervention (9–108). Mean age was 47years (26–61). Seven patients presented stroke, 4cranial trauma, 3medullar trauma, 3patients suffered respectively from cerebral palsy, cerebral tumor and cervical myelopathy. The tibialis posterior was transferred on the tibialis anterior in 9cases, on the peroneus brevis in 5cases, on the calcaneocuboid capsule once and on both tibialis anterior and calcaneocuboid capsule once. Three isolated talo-navicular arthrodesis and one triple arthrodesis were associated.ResultsWe found the need of orthosis decreased (P=0,021), 9patients no longer needed their orthosis. The walking distance was significantly increased (P=0,031) in 9patients. The average satisfaction score was 2.71/4 (0–4).On average, the maximum active dorsiflexion reached the neutral position (−20 to 20) with knee extended and 6° (−10–20) with knee flexed; the arc of movement averaged 9° (0–40) knee extended and 16,2° (0–40) knee flexed during analytic testing and 2,8° (0–10) when walking. Only half of the patients presented a tenodesis effect when walking. Dorsiflexion strength averaged 1,5 (0–5). Six patients had a normal plantar footprint, 8 a cavus foot and 2 a flatfoot, without any worsening compared to preoperative status. The Djian angle averaged 119,5° (105–138) and the hindfoot alignment angle was 7,7° valgus. There was no significant difference with the non-operated foot.DiscussionThe tibialis posterior transfer is effective in foot-drop in half of the patients, with a tenodesis effect that is not systematic in spastic patients. A flat valgus foot does not appear to be a long-term complication of this procedure

Parallelizable MACs Based on the Sum of PRPs with Security Beyond the Birthday Bound

The combination of universal hashing and encryption is a fundamental paradigm for the construction of symmetric-key MACs, dating back to the seminal works by Wegman and Carter, Shoup, and Bernstein. While fully sufficient for many practical applications, the Wegman-Carter construction, however, is well-known to break if nonces are ever repeated, and provides only birthday-bound security if instantiated with a permutation. Those limitations inspired the community to several recent proposals that addressed them, initiated by Cogliati et al.\u27s Encrypted Wegman-Carter Davies-Meyer (EWCDM) construction. This work extends this line of research by studying two constructions based on the sum of PRPs: (1) a stateless deterministic scheme that uses two hash functions, and (2) a nonce-based scheme with one hash-function call and a nonce. We show up to 2n/3-bit security for both of them if the hash function is universal. Compared to the EWCDM construction, our proposals avoid the fact that a single reuse of a nonce can lead to a break

Concurrent validity of the ZeroWire® footswitch system for the measurement of temporal gait parameters

International audienceBackground: In contrast to wearable tools (like in-shoe) sensors, lab-based gait assessment (using pressure-sensitive mats or cameras) only acquire data over short distances in non-ecological environments.Research question: To examine the concurrent validity of a wearable ZeroWire® footswitch system (Aurion Srl, Milan, Italy) vs. the GAITRite® walkway (CIR systems Inc., NJ, USA) for recording temporal gait parameters.Methods: We included 40 healthy participants in a prospective, single-center study. Temporal gait parameters were recorded simultaneously with the ZeroWire® and GAITRite® systems while each participant walked at three different speeds (slow (60steps/min), comfortable and maximum). To measure the validity, we calculated the interclass correlation coefficient (ICC) and the coefficient of variation (CV) for each parameter (gait cadence, stride time, step time, stance time, and single-support and double-support times). We also performed a graphical analysis using the Bland and Altman method.Results: The footswitch system showed moderate-to-excellent concurrent validity vs. the GAITRite mat. The degree of agreement between the two assessments was greatest at the maximum gait velocity showed, with very good validity (ICC > 0.91) seen for most parameters, whereas agreement ranged from moderate to very good for the other speeds. Independently of the gait speed, the highest levels of agreement were recorded for gait velocity, cadence, stride time, step time, and stance time. According to the CVs, both systems showed the same accuracy and double-support time was the more variable parameter.Significance: The ZeroWire® footswitch system appears to be valid for assessing temporal gait parameters (and particularly gait cadence and stride, step and stance times in healthy participants). It is likely to be well suited to the assessment of gait parameters under ecological conditions and in dual-task gait paradigms

Impact de la fatigabilité musculaire du quadriceps sur les cocontractions spastiques entre quadriceps et ischiojambiers et sur la marche chez les patients hémiparétiques post-AVC

International audienceContexteLa cocontraction spastique est fréquemment rencontrée chez les patients post-AVC mais l’influence de la fatigue musculaire sur ces cocontractions est mal connue.ObjectifsÉvaluer l’effet induit par un protocole isocinétique de fatigue du quadriceps sur le degré de cocontraction entre extenseurs de genou (droit antérieur, vastes latéral et médial) et ischio-jambiers (semi-tendineux) durant la flexion de genou chez des patients hémiparétiques post-AVC chroniques. Secondairement, évaluer l’effet de ce protocole sur le degré de spasticité du quadriceps, sur les paramètres spatio-temporels et de l’endurance à la marche.MéthodesÉtude exploratoire prospective monocentrique de 27 patients hémiparétiques présentant un stiff knee gait. Protocole de fatigue côté hémiparétique : alternance d’extensions actives concentriques maximales de genou avec retours passifs en flexion jusqu’à fatigue musculaire effective. Paramètres mesurés avant/après protocole : indice EMG de cocontraction (ICC) entre droit antérieur, vastes latéral et médial versus semi-tendineux, indice de recrutement agoniste du semi-tendineux (IRA), spasticité (Tardieu), pic de couple de flexion et extension de genou, paramètres spatio-temporels (Gaitrite), vitesse maximale (10MWT), endurance et effort perçu à la marche.RésultatsAprès fatigue, diminution significative du pic de couple isométrique du quadriceps (p = 0,014) sans modification majeure de l’ICC et de l’IRA. Amélioration significative de la spasticité du quadriceps, du 10MWT, de l’endurance et des paramètres spatio-temporels de marche (vitesse, cadence et longueur du pas côté parétique).ConclusionEffet positif d’un protocole isocinétique de fatigue du quadriceps sur plusieurs paramètres de marche dont la vitesse, sans effet sur les cocontractions spastiqueschez des patients hémiparétiques chroniques post-AVC

Surgical treatment of disabling shoulder hypertonia in patients with brain injury

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