What’s the best way to stretch the hamstrings?

The Introduction

hamstringsDespite its widespread use in sport, one area of sport science that has not been looked at in depth is stretching and flexibility. Coaches and clinicians all recommend stretching and most athletes do it as part of warm-up and cool down as well as part of normal training to prevent injury. Previous research has shown that:

  • 3-4 sets of stretches should be done with each stretch held for 30 seconds.
  • Best results come from 5 or more sessions a week.
  • Ballistic (bouncing) stretches are less effective and may cause injury.
  • PNF (contract-relax) type stretches may be more effective than static stretches.

The two basic types of stretching include active stretching, in which range of motion is increased through voluntary contraction (bouncing and PNF), and passive stretching, in which range of motion is increased through external assistance (holding or using a towel or band). This study aimed to determine which of four types of stretching is most effective in improving hamstring length. The results have strong implications for all of we masters athltes who MUST stretch!

The Research

One hundred male (45 females, 55 males) subjects between the ages of 21 and 57 were enrolled in the study. They were randomly assigned to one of 5 different groups comparing different hamstring-stretching techniques:

  1. Control group who did no stretching and maintained normal activities.
  2. A passive stretch group that lay on their back on the floor, lifted their leg straight up and used a strap under their arch to stretch the hamstrings.
  3. An active stretch group that did the same stretch as above but with no strap (but holding the thigh with their hands) and trying to straighten the leg to create the hamstring stretch.
  4.  An active assisted stretch where the same position as above was achieved but with the heel against a wall and the hamstrings of the stretched leg contracted and the ankle ‘pumped’ by pushing against a strap.
  5. A passive stretch in the same position as 4 above but with no contraction of the hamstrings.

Stretching was done 3-5 times a week with 3 repetitions done and held for 30 seconds each.

Outcome measures, including hamstring length and perceived level of hamstring tightness, were recorded on all subjects initially, at 4 weeks, and at 8 weeks.

The Results

After 4 weeks of stretching, there was a statistically significant improvement in hamstring length using active stretches (3 and 4 above) as compared with passive (2 and 5) stretches. From weeks 4 through 8, hamstring length for the active stretching groups decreased. After 8 weeks of stretching, the straight leg raise passive stretch group had the greatest improvement in hamstring length. Also, using PNF in the active stretch (3 above) provided better knee range-of-motion improvements than the passive methods did. The more frequently stretching was done and the further they pushed into range the better the results.

The So What?

Thus, gains in flexibility are time dependent and should thus be done consistently and frequently and, most importantly, be achieved by end of range pressure. It appears the straight leg raise passive stretch (number 5 above) and the PNF (number 4 above) have the greatest benefits to increasing hamstring length.

Flexibility for masters athletes is discussed at length in chapter 9 of The Masters Athlete. The chapter highlights in detail the methods discussed in this paper.

Fasen JM, O’Connor AM, Schwartz SL, Watson JO, Plastaras CT, Garvan CW, Bulcao C, Johnson SC, Akuthota V.  A randomized controlled trial of hamstring stretching: comparison of four techniques. Journal of Strength and Conditioning Research. 23(2):660-667.