Running is something that can be done almost anywhere. It is easy. It requires very little thinking or planning whether it’s at home, while on vacation or in a familiar training facility or environment. Whether it is done for leisure, to lose weight or as part of training for sport, running is an effective training tool. However, it is important to understand that the hamstrings are three muscles that are directly involved with the propulsion of the running cycle. The latest research on hamstring injuries may surprise you.
There is a growing incidence of hamstring injuries in athletes. So whether you are running for fun, or training an athlete for a particular sport, understanding the mechanics of running, and the latest evidence-based research and strategies can help you with new tools to help clients with pre-existing or chronic hamstring pain.
Movement Analysis: Running
The running cycle can be divided into two phases: the contact phase and the swing phase.
1. The contact phase (support phase; drive phase): is where one foot is in contact with the ground, (i.e. from foot strike to toe-off) foot strike/contact(when the foot hits the ground), mid support(transference of weight from knee flexion to knee extension) and take off(propulsion).
2. The swing phase constitutes when the lower extremity is swinging through the air, i.e., from follow-through, forward swing and foot descent(terminal swing). During the second half of the swing, the hamstrings are active, lengthening and absorbing energy from the decelerating limb in preparation for foot contact. “
The greatest musculotendinous stretch is placed on the bicep femoris biomechanically, which may contribute to it’s tendency to be more often injures than the other two hamstring muscles during high speed running.1 Injuries Hamstring injuries constitute a substantial percentage of musculoskeleal injuries in high school, collegiate and professional levels. Athletes who particpate in track, football, australian rules football(AFL) and rugby are especially prone to this injury Given the demands of these particular sports, the extreme stretch incurred by the hamstring muscle.1 In the Australian Football League (AFL), 16% of all playing time missed was through hamstring strains.
Another feature of muscle strains is the recurrence rate, 34% of hamstring strains in the AFL being recurrences, making hamstring injuries one of the most common sources of injury and reinjury among footballers.2
Hamstring strains are commonly classified or graded according to the amount of pain, weakness and loss of motion, resulting in grades I(mild), grades II(moderate) and grades III(severe).
Treatment of hamstring strains is not part of this article. However, most grade I sprains require up to 4 weeks of recovery as compared to grade II sprains which can take up to 8 weeks. Grade III sprains are severe and usually are season ending to an athlete. Requiring a minimum of 12 weeks to heal and are prone to reinjury as previously stated.
In a study by Chumanov (2007), measured the speed and influence of individual muscles on hamstring stretch, loading, and work during the swing phase. T hey examined19 athletes sprinting on a treadmill at speeds ranging from 80% to 100% of maximum speed. Simulated lower extremity joint angles and model predicted excitations were measured. Results indicated that individual muscles on hamstring stretch was larger at maximal speed when compared to slower speeds. The biceps femoris (BF) exhibited greater musculotendon stretch than the semimembranosus (SM) and semitendinosus (ST) muscles. The conclusion was that hamstring strain injury during sprinting may be related to the performance of large amounts of negative work over repeated strides and/or resulting from a perturbation in pelvic muscle coordination that induces excessive hamstring stretch in a single stride.3
Can Hamstring Injuries Be Prevented?
Arnason et al(2008) wanted to test the effect of eccentric strength training and flexibility training on the incidence of hamstring strains in soccer. He examined 17-30 elite soccer teams from Iceland and Norway. The first two seasons were used as baseline, while intervention programs consisting of warm-up stretching, flexibility and/or eccentric strength training which were introduced during the 2001 and 2002 seasons. A control group and intervention group were established. Results indicate that the teams who used the eccentric training program had a lower incidence of hamstring strains compared with teams that did not use the program. In another study by Verall et al (2005), followed a single team of Australian Rules football players examining the effect of a specific intervention program on the incidence and consequence of hamstring muscle strain injuries.
Results: A beneficial effect was demonstrated with a smaller number of players having hamstring injuries, a lower number of competition games missed being recorded, and a decrease in hamstring strain incidence per 1000 hours of playing time following the intervention program.
Conclusion: Implementing sport specific training drills resulted in a significant reduction in the number and consequences of hamstring muscle strain injuries.
Prevention Strategies
One common criticism of rehabilitation programs is the lack of attention of strengthening musculature adjacent to the hamstrings. This includes the lumbo-pelvic girdle and hip abductors. It has been shown that warm up exercises(activity) can be incredibly helpful for increasing blood flow, increasing pliability of the muscle, increasing mental acuity to name a few.
Listed below are drills and exercises that can you can use with your athletic client to improve flexibility, increase awareness and decrease injuries.
1. Warm up drills(All warm-up perform for 30 second 2-3 bouts)
- Statues(high knee to arm)- Have your client raise one arm and the opposite knee to simulate running.
- Jogging in place
2. Agility(Perform agility drills in an environment with sufficient space beginning with 20′ x 2 with 2-3 bouts of each)
- Grapevine-cross long leg over the other making sure that the client minimally rotates the trunk.
- Grapevine with arms by their side.
- Grapevine and pass the client a ball, medicine ball when instructed.
In the next section, simple sport specific exercises that you can teach athletic client listed below targeting the hamstrings.
| Figure 1. Diagonal reverse lunge | Figure 2. Hamstring curls with bridging with trunk rotation. |
Additional Exercises:
Horizontal Leg press machine
The traditional position is seated with feet on a push plate. Try this approach. First, position the client in a side position with their top leg and bottom leg on the push plate. Before using any weight, take all the weight off for safety. Next, ask the client to bend the bottom knee so that literally the top leg is pushing only. Once they can perform this correctly, add 50% of your normal weight to begin with, going slowly, watching form and most importantly, to be safe. This is an excellent biomechanical variation that targets the hamstrings from a different angle and can be very effective.
Cable or exercise tubing press outs seated
First, explain to your client this “different exercise” before instructing. Place exercise tubing around the client’s ankle and have them scoot forward(therefore this places tension on the rubbing as it is tied behind them). Then ask them while seated to bend the opposite knee and with the leg that has the tubing is to flex their knee/hip complex then extend. The client will feel this in their glute max initially.
Now to target the hamstring, adjust their position as stated in the modified leg press exercise previously mentioned. Have the client lie on his or her side so that both feet in essence are facing 12 pm (like on a clock). The top leg has the tubing on it. Instruct the client to “scoot” away which places tension on the tubing and instruct the client to flex and extend their leg which in essence is like kicking at varying angles — 10 am, 12 pm, 2 pm as on a clock face. Then repeat on the other leg. If the client does not feel anything in their hamstring, increase the distance or switch to another, more resistant tube.
Summary
Hamstring injuries like any injury can be mild or extreme, affecting the athletic client’s not only performance but mental mindset. It is also important to not only motivate the client who may be recovering from an injury, to help them with other strategies to keep them upbeat and avoid becoming depressed which I have seen with not only my athletic patient’s over the years, but have learned while now studying abroad in Australia covering Rugby.
Understanding that the hamstring complex is made up of three muscles that synergistically are powerful producing force, speed and quickness is important. However, understanding per the research, the biceps femoris is the weakest of the three and can take up to twice as long to heal and recover from is even more important. Awareness and prevention are both key. Train the client in multi-planes and this can strongly aid in preventing hamstring injuries making training fun!
About the Author
Chris Gellert, PT, MPT, CSCS, CPT is the President of Pinnacle Training & Consulting Systems. Gellert offers educational workshops on human movement, home study courses on human movement, and consulting services. As a clinician, author, presenter, with extensive experience having treated and worked with individuals’ of all ages with various spinal injuries, post surgical conditions, traumatic and sport specific injuries in industrial rehabilitation, outpatient and private practice settings. He is presently pursuing an advanced Master’s Degree in Orthopedics/Manual Therapy in Australia. For more information, contact www.pinnacle-tcs.com or email him at [email protected]
