Support for a 'knee related' hamstring mechanism

[Whoskins]

More evidence for the complex nature of human anatomy which traditionally has been thought of as a basic 'origin and insertion' model. The anatomical relationship between the knee and hamstring and its role in injury causation has been discussed in literature reviews:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15922230&query_hl=5

This further supports the complex multifactorial aetiology behind hamstring injury and the requirement for multimodal injury management addressing both kinetic and kinematic considerations and local and non-local factors.

Tubbs RS, Caycedo FJ, Oakes WJ, Salter EG. Descriptive anatomy of the insertion of the biceps femoris muscle. Clin Anat. 2005 Nov 10; [Epub ahead of print]

The biceps femoris is the most lateral component of the so-called hamstring muscles. Classically, this muscle's insertion into the head of the fibula has been described but further details of its anatomy have not been universally appreciated. Additional insertions into the crural fascia and tibia have been described. We dissected 56 cadavers paying especially close attention to the insertion of the biceps femoris muscle. The tendon of this muscle was found to have both medial and lateral slips each with an anterior and posterior component. Further, we found an attachment not only into the lateral condyle of the femur but also the popliteus tendon and arcuate popliteal ligament. Our study has found that the tendon of insertion of the biceps femoris muscle is more complex than described previously and suggests that this tendon may be far more important in knee stability based on the multiple attachment sites found. We hypothesize that there may be a synergistic effect between the biceps femoris and the popliteus muscles based on our findings of an additional attachment of the biceps femoris tendon into the popliteus tendon. This study provides new detailed nomenclature for the description of the tendon of insertion of the biceps femoris muscle and indicates that the current description of the insertion of the tendon of the biceps femoris muscle should be revised. The clinician must have a thorough understanding of this anatomy before correct therapeutic maneuvers can be implemented.

[Whoskins]

More good work from Thelen's group supporting an eccentric mechanism to hamstring injury, which has been linked to kinetic considerations.

Thelen DG, Chumanov ES, Best TM, Swanson SC, Heiderscheit BC. Simulation of Biceps Femoris Musculotendon Mechanics during the Swing Phase of Sprinting. Med Sci Sports Exerc. 2005 Nov;37(11):1931-8.

INTRODUCTION/PURPOSE:: Characterization of hamstring mechanics during sprinting is fundamental to understanding musculotendon injury mechanisms. The objective of this study was to use muscle-actuated forward dynamic simulations to investigate musculotendon mechanics of the biceps femoris long head during the swing phase of sprinting. METHODS:: We used a three-dimensional linked segment model with 26 Hill-type musculotendon actuators to simulate swing phase dynamics. Muscle excitations were computed that drove the linked segment model to track measured hip and knee motion of an individual sprinting on a treadmill. The simulations were used to investigate the effect of tendon compliance on the excursions and power development of the muscle and tendinous components of the biceps femoris. RESULTS:: The biceps femoris musculotendon complex underwent a stretch-shortening cycle over the latter half of swing phase, with the shortening portion occurring in the final 10% of the gait cycle. Biceps femoris excitation increased markedly between 70 and 80% of the gait cycle and continued through the end of swing. Following the onset of excitation, stretch of the muscle component slowed considerably while the tendon lengthened and stored elastic energy. Simulating the sprinting movement with a more compliant tendon increased tendon elastic energy storage, thereby reducing peak muscle stretch and negative muscle work. CONCLUSIONS:: Muscle-actuated forward dynamic simulation provides a powerful approach for investigating biomechanical factors that may contribute to the occurrence of hamstring musculotendon injuries.

[lennongardner]

I have this exact problem as discussed n this article. I have had this pain for 2 years now. I contacted a world renowned doctor in Vail, Co. I had arth surgery and still continue to have most of the pain. I was treated for inflammation of the popliteal tendon. I had a kenalog (cortisone ) injection. It felt better for a short time. It still hurts to squat, any type of weight bearing and also when a where high heels. I get fricture burn when I ride a bike with resistance. I had ITB therapy for a year also, no pain relief. Can anyone relate? Please advise.