Optimal Contraction Intensity During Proprioceptive Neuromuscular Facilitation for Maximal Increase of Range of Motion

Abstract

An informal review of literature on the use of postisometric relaxation (PIR) type proprioceptive neuromuscular facilitation (PNF) indicates that the force of contraction requested from the athlete ranges from 10 to 100% of maximum voluntary isometric contraction (MVIC). The purpose of this study was therefore to determine if an optimal contraction intensity to elicit maximum positive change in range of motion (DeltaROM) exists. This research question was tested across a convenience sample of 56 (37 male and 19 female) university athletes. Target contractions during PNF interventions were set at 20, 50, and 100% MVIC. Pre- and post-PNF intervention hip flexion range of motion (ROM) was measured on a unilateral straight leg raise. The target MVIC of 20, 50, and 100% elicited mean pre-post intervention DeltaROM of 8.4, 12.9, and 11.6 degrees , respectively (all p < or = 0.0001). Differences in pre-post intervention DeltaROM between target contraction intensities were also significant (p = 0.016 to < or = 0.0001). A peak DeltaROM of 13.3 degrees was found at a PNF contraction intensity of 64.3% MVIC. Where optimizing increased ROM in healthy athletes is the desired outcome of PIR-PNF application, coaches and trainers should elicit contraction intensities of approximately 65% MVIC.

Facilitação Neuromuscular Proprioceptiva Na Marcha Em Pacientes Com Sequela De Acidente Vascular Encefalico

“…Ao aplicar a FNP para os músculos de extensão da articulação do quadril, pesquisadores descobriram melhora de aproximadamente 60% da contração isométrica voluntaria e aumento da amplitude de movimento. No presente estudo, os pacientes apresentaram grande melhora na marcha, conscientizando-se e mantendo a funcionalidade do movimento de dorsiflexão (23) . Algumas pesquisas revelam uma melhora significante na função motora e na funcionalidade de 11 pacientes sobreviventes de AVE, o que atesta os resultados aqui encontrados (24)(25) .…”

Immediate effect of contract-relax antagonist-contract method on iliopsoas muscle and hamstring muscle stretching in chronic non-specific low back pain

“…The target hip was moved toward the floor until the participant felt a mild stretch sensation. Then, the participant was asked to perform a sub-maximum voluntary isometric contraction (MVIC) (approximately 25% MVIC) [21] of the iliopsoas muscles for 10 s, then completely relax for 10 s. During relaxation, the antagonistic gluteal muscle is contracted isometrically for 10 s. The participant's leg was slowly moved to the new range until a mild stretch sensation was felt and held at this position for 20 s. This holdrelax stretching to iliopsoas, and isometric contraction of gluteus maximus was repeated 5 times, followed by a 1-min rest, for 15 min. All subjects were immediately measured after intervention for post-test by the same examiner.…”

Alongamento passivo agudo não afeta a atividade muscular máxima dos ísquiotibiais

“…O DFIA pode estar relacionado à dose-resposta do treinamento, tipo de alongamento (estático, dinâmico ou FNP) (Herda, et al, 2008) ou características musculares específicas (tipos de fibras), podendo durar entre 6 a 90 minutos (Ryan, et al, 2008). Existem duas hipóteses primárias para explicar tal fenômeno: (1) Fatores neurais como a diminuição da ativação muscular, alteração das estratégias de controle motor, efeito de inibição do sistema nervoso central e diminuição de sensitividade dos proprioceptores articulares e musculares (Herda, et al, 2008); (2) Fatores mecânicos como a diminuição da rigidez músculo-tendínea que pode afetar a curva de comprimento-tensão e/ou a taxa da velocidade de encurtamento dos sarcômeros (Cramer & Housh, 2005;Fowles, Sale, & MacDougall, 2000;Herda, et al, 2008;Ryan, et al, 2008 -López et al, 2010;La Torre, et al, 2010;Ryan, et al, 2008;Sheard & Paine, 2010), produzindo diferentes modificações nos componentes elásticos em série ou mesmo no controle neural dos sujeitos avaliados (Beedle, et al, 2008;Molacek, Conley, Evetovich, & Hinnerichs, 2010…”