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Biomedical subjects

P Blanpied

Publications and source records attributed to P Blanpied.

6 recordsLinked to original sources
PubMed2000

Effectiveness of lateral slide exercise in an anterior cruciate ligament reconstruction rehabilitation home exercise program.

STUDY DESIGN: Two-group repeated measures design using a sample of convenience of subjects with anterior cruciate ligament (ACL) reconstructive surgery. OBJECTIVES: To determine the effect of incorporating one specific weight-bearing exercise (lateral slide exercise using a slide board) into an ACL reconstruction home exercise program. BACKGROUND: Reduced clinic visits have increased the importance of home exercise programs in knee ligament reconstruction rehabilitation. Few studies have been conducted to test the efficacy of specific exercises as part of a home-based treatment program on subjects who have undergone ACL reconstruction. METHODS AND MEASURES: Fourteen subjects who underwent patella tendon autograft reconstruction on one of their ACLs were studied. Testing consisted of the following 4 measurements: peak isometric knee extension torque, peak isometric knee flexion torque, maximum lateral step height, and lateral step-up repetitions to fatigue. Subjects were pretested at 8 weeks after surgery and were randomly placed into either a control or experimental group. The postsurgical rehabilitation was similar for both groups, except the experimental group incorporated lateral slide exercise into their home exercise program. All subjects were re-evaluated 14 weeks after surgery. RESULTS: A 2-way repeated measure ANOVA (group by test session), and posthoc testing revealed significant improvements in the slide group for quadricep strength (101.9 +/- 31.3 N m to 140.5 +/- 31.3 N m of torque), while the control group showed no significant increase (125.1 +/- 61.7 N m to 125.8 +/- 45.1 N m of torque). Lateral step height also improved in the slide group (from 22.9 +/- 5.3 cm to 28.7 +/- 5.6 cm), while the control group showed no increase (20.0 +/- 4.5 cm to 20.7 +/- 3.4 cm). Both groups increased in lateral step-up repetitions to fatigue. CONCLUSION: Including lateral slide exercise in a home exercise program after ACL reconstruction appears to improve knee extension strength.

Adult↗
PubMed1998

The effects of serial stretch loading on stretch work and stretch-shorten cycle performance in the knee musculature.

Training methods to optimize stretch-shorten cycle performance and an active muscle's ability to resist a sudden stretch (stretch work) and the relationship between the two have not been fully explored. The purpose of this study was to examine the effects of an 8-week strengthening program of serial stretch loading on stretch work and stretch-shorten cycle performance in the quadriceps and hamstring muscles. Thirty-one asymptomatic subjects participated in pre- and post-tests of maximum voluntary isometric contractions, stretch work and stretch-shorten cycle trials, and single-leg vertical jumps. The training portion consisted of progressively resisted isotonic single-leg squats. One leg exercised against an isotonic load with serial stretch loading, while the other leg exercised against isotonic load alone. Training resulted in strength gains in both legs indicated by the increase in weight lifted during training, but not by maximum voluntary isometric contractions. Vertical jump height increased in both legs. In the hamstring, stretch work decreased and stretch-shorten cycle performance increased in both legs. In the quadriceps, serial stretch loading intervention resulted in increased stretch-shorten cycle performance and no significant change in stretch work. The correlation between stretch-shorten cycle and stretch work was weak but significant. These findings suggest that the use of serial stretch loading could improve muscular performance and enhance a muscle's potential for dynamic stabilization.

Adult↗
PubMed1995

The effects of different stretch velocities on average force of the shortening phase in the stretch-shorten cycle.

The function of muscle is thought to be enhanced through the use of a stretch-shorten cycle. Although this pattern of muscle function is commonly used, optimal parameters of the cycle are not well understood. The purpose of this paper is to review the stretch-shorten cycle pattern of muscle function, as it applies to human movement, and to present a research study that investigated the effects of different stretching speeds on the average concentric forces during stretch-shorten cycles. Twenty-two women performed repeated plantar flexor stretch-shorten cycles on a Kin-Com dynamometer at approximately 60% of their isometric plantar flexor maximum. Sequential trials were recorded for 15 seconds at three different speed combinations (eccentric speed/concentric speed): 50/180 degrees/sec, 100/180 degrees/sec, and 150/180 degrees/sec. Eighteen cycles from each speed combination were chosen for analysis based on contributing to an equal plantar flexor activity among the speed combinations. Analysis of variance indicated that the speed combination that most closely approximated normal walking (50/180 degrees/sec) resulted in the highest average concentric forces. Analysis of covariance indicated that the highest forces were due, at least in part, to a higher averaged interphase force.

Adult↗
PubMed1993

The difference in stiffness of the active plantarflexors between young and elderly human females.

The purpose of this investigation was to determine the difference in the intrinsic stiffness of the active plantarflexor muscles between young and elderly human females, and to determine changes in this stiffness associated with a 6-week strengthening exercise program. Intrinsic muscle stiffness was determined by measuring the resistance in the first 62 milliseconds offered by the muscle to multiple single stretch trials at 20% to 60% of maximal isometric contraction. Stiffnesses were related to pre-stretch torque (K/PST) by a linear fit. The K/PST relationship of the elderly subjects exhibited a steeper slope, indicating a greater increase in stiffness with an increase in pre-stretch torque. The effect of testing subjects at identical relative, but different absolute pre-stretch torque levels precluded definitive conclusions on possible stiffness differences between the age groups. After the strengthening exercise program, the plantarflexors showed an increase in maximum produced torque, and a decrease in stiffness as well as a decrease in the slope of the K/PST relationship.

Adult↗
PubMed1992

Human plantarflexor stiffness to multiple single-stretch trials.

The purpose of this investigation was to determine the influence of different stretch velocities, different rates of pre-stretch force development, and different pre-stretch muscle lengths on the intrinsic stiffness exhibited by the quasi-statically contracting active human plantarflexors during multiple single-stretch trials at 20-60% of maximum isometric contraction. Subjects were positioned prone, with the knee flexed 1.57 rad(90 degrees), shank stabilized, and foot secured in a hard plastic orthotic. Slowly increasing isometric plantarflexion force was produced until the plantarflexors were stretched by a rapid 0.2 rad (12 degrees) dorsiflexion movement. Plantarflexion forces and ankle positions were determined during these stretches as well as during resting stretches when the muscle was inactive. Resting forces were subtracted from the active trials, forces converted to torques, and stiffnesses determined for the first 62 ms of the stretch. The slope of the stiffness vs pre-stretch torque relationship averaged 4.30 +/- 0.34 Nm rad-1 Nm-1. Little difference was found between stiffness determined through the single-stretch method and the results of previous studies employing different mechanical inputs. Differences in stiffnesses with different stretching velocities were caused by computational artifact rather than by differences in intrinsic muscular reaction. Faster rates of pre-stretch force increase prior to the stretch resulted in slightly lower stiffnesses. Different pre-stretch muscle lengths apparently did not result in different stiffnesses. The shape of the torque vs displacement curve was remarkably insensitive to the planned manipulations of the testing conditions, responding in a stereotypical manner.

Adult↗