Improving the sensitivity of the hop index in patients with an ACL deficient knee by transforming the hop distance scores

BACKGROUND: The one leg hop for distance is one of the most commonly employed functional tests utilized in the evaluation of the ACL deficient and reconstructed patient. While the reliability of the hop test scores has been well established, validity studies have revealed low sensitivity rates in detecting functional limitations using the hop index (the ratio or percentage of limb performance). However, the impact of the inherent limitations associated with the hop index have not been investigated to date. One specific limitation relates to the impact of the differences in the underlying hop distance scores. Therefore, this pilot study set out to determine: 1) the impact that between limb differences in hop distance has on the sensitivity of the hop index in detecting functional limitations and; 2) whether a logarithmic transformation of the underlying hop distance scores improves the sensitivity of the hop index. METHODS: A cross sectional design involving the evaluation of one leg hop for distance performance in a consecutive sample of 10 ACL deficient males with an isolated ACL tear awaiting reconstructive surgery and nine gender, age-matched controls. RESULTS: In the ACL deficient, the hop index was associated with the distance hopped on the non-injured limb (r = -0.66, p = 0.04) but not on the injured limb. Transformation (logarithmic) of the hop distance scores and re-calculation of the hop index using the transformed scores increased the sensitivity of the hop index in the detection of functional limitations from 20 to 60% and 50 to 70% using the normal limb symmetry reference norms of ≥ 85% and 90% respectively. CONCLUSION: The distance hopped on the non-injured limb is a critical factor in detecting functional limitations using the hop index in patients with an ACL deficient knee. Logarithmic transformation of the hop distance scores minimizes the effect of the arithmetic differences between limbs however; the sensitivity of the hop index in detecting abnormal limb symmetry remains low

Influência do intervalo de tempo entre as sessões de alongamento no ganho de flexibilidade dos isquiotibiais Influence of the time interval between stretching sessions on increased hamstring flexibility

CONTEXTO: A otimização do treino de flexibilidade está relacionada com o uso de parâmetros adequados de alongamento. Entretanto, o intervalo de tempo adequado entre as sessões de alongamento tem sido pouco investigado. OBJETIVO: Verificar se a variação no intervalo de tempo entre sessões de alongamento influencia no ganho de flexibilidade. MÉTODOS: 28 mulheres, com idade de 22,5 ± 1,8 anos, foram distribuídas aleatoriamente em três grupos. Aplicaram-se 10 sessões de alongamento nos isquiotibiais do membro direito. O grupo 0X (n = 8) foi o controle e não recebeu alongamento. O grupo 3X (n = 10) alongou três vezes por semana (intervalo de 48 horas) e o grupo 5X (n = 10), cinco vezes (intervalo de 24 horas). Aplicaram-se 10 sessões de alongamento (sustentar-relaxar) nos isquiotibiais direitos. As medidas foram tomadas por análise fotométrica no programa AutoCad® 2000. A análise estatística foi realizada com ANOVA e teste post hoc de Newman-Keuls adotando um p-valor referencial de 0,05. RESULTADOS: Após 10 sessões, identificou-se aumento da flexibilidade nos grupos experimentais, porém sem diferença entre estes. O grupo 3X aumentou significativamente a partir do 10º dia do programa (quinta sessão) e o grupo 5X, a partir do terceiro (terceira sessão). CONCLUSÕES: O alongamento aumenta a flexibilidade dos isquiotibiais, independente do tempo entre as sessões (24 ou 48 horas); e a variável tempo não influencia o ganho de flexibilidade total. Porém, com cinco sessões semanais, ganha-se flexibilidade mais rapidamente. Isso sugere que o ganho de flexibilidade é sessão-dependente.<br>CONTEXT: The optimization of flexibility training is related to the use of ideal stretching parameters. However, the time interval between sessions has been little investigated. OBJECTIVE: To verify if the variation in time interval between stretching sessions influences in flexibility gain. METHODOLOGY: Twenty-eight women, average age of 22.5 ± 1.8 years, were randomly distributed into three groups. Group 0X was the control and performed no stretching. Group 3X (n = 10) took part in three sessions per week (interval = 48 hours) and group 5X (n = 10) in five times (interval = 24 hours). Ten stretching sessions were applied (hold-relax) to the right hamstring. The measurement of active knee extension was performed using photometric analyses on AutoCAD® 2000 software. Statistical analysis was carried out with ANOVA and Newman-Keuls post hoc test for a significance level of p < 0.05. RESULTS: After 10 sessions, increased flexibility was identified in the experimental groups (p < 0.01), but with no difference between them. Group 3X significantly increased flexibility from the tenth day of the program (fifth session) and group 5X from the third day (third session). CONCLUSIONS: Stretching increases hamstring flexibility, regardless of the time between sessions (24 or 48 hours). Moreover, the interval between the sessions does not influence total flexibility gain. However, with five weekly stretching sessions, flexibility increases more rapidly than it does with three, suggesting that flexibility gain is session-dependent