Research Review: Force Transmission Through the Thoracolumbar Fascia with Passive and Active Motion of Latissimus Dorsi
By Stefanie DiCarrado DPT, PT, NASM CPT & CES
Edited by Brent Brookbush DPT, PT, MS, PES, CES, CSCS, ACSM H/FS
Original Citation:
Carvalhais, VO., Ocarino, Jde M., Araújo, VL., Souza, TR., Silva, PL., Fonseca, ST. (2012). Myofascial force transmission between the latissimus dorsi and gluteus maximus muscles: An in vivo experiment. Journal of Biomechanics 46. 1003-1007 - ABSTRACT
Note the connection & fiber orientation of the latissimus doris, thoracolumbar fascia, and contralateral gluteus maximus
Why is this relevant?:
Past research has indicated force transmission can occur through fascia and affected muscle fibers within the same muscle, between muscles with a shared fascial connection, and between non-muscular tissue that shares a fascial connection (1,2,3,4). The connections that allow for force transmission are commonly described as fascial trains, slings, or subsystems throughout the body. The Posterior Oblique Subsystem (POS) is traditionally defined as the ipsilateral latissimus dorsi (LD) , the thoracolumbar fascia (TLF), and the contralateral gluteus maximus (GMax) . Human movements such as walking, stair climbing, running, and hopping may rely on POS synergy where arm extension occurs simultaneously with contralateral leg extension. A better understanding of this synergy may imply interventions for increasing performance, rehabilitation, and therapeutic intervention for activities of daily living.
Study Summary
| Study Design | Experimental Descriptive Study |
| Level of Evidence | Level IIb: Evidence from a non experimental study |
| Subject Demographics |
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| Outcome Measures |
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| Results | |
| Conclusions | Active and passive tension on the LD can influence hip movement and joint stiffness. These force transmissions as noted here and in POS documentation are necessary for functional tasks such as walking and running. It is likely that tension in the GMax will affect tension in the LD with rippling effects to the glenohumeral (GH) and scapulothoracic (ST) joints. Therefore one should consider top down and bottom up force transmissions during movement assessment. |
| Conclusions of the Researchers | Both active and passive tension of the LD can influence the position of the hip and the stiffness of the joint. The thoracolumbar fascia (TLF) would allow for these forces to be transmitted as it is anatomical link between the two muscles. Biomechanical models should incorporate force transmission via fascia rather than only through muscle to bone via tendon or they risk missing the complexity of joint movement. |
* The authors defined joint stiffness as the change in the total force exerted across the hip by opposing muscle groups as the joint position changes
Review & Commentary:
This study provides strong evidence of force transmission through the thoracolumbar fascia (TLF) from the LD to the GMax in healthy individuals. The authors analyzed EMG and dynamometric (movement) data of the dominant upper extremity and contralateral lower extremity. Subjects initially performed three repetitions of shoulder adduction with scapular depression to record the maximal voluntary isometric contraction (MVIC) for the LD to be used as a comparison during testing. To measure hip rotation, researchers used an isokinetic dynamometer for three different testing conditions, during which the subjects laid prone while their lower extremity moved passively from 25° of IR to 25° of ER.. Testing conditions consisted of:
- Arms resting at their side
- Dominant arm resting in 120° of shoulder flexion with scapular elevation (maintained via a cable attached to the subject's wrist);
- Active shoulder adduction and scapular depression
Researchers maintained the integrity of the data collected by employing a standardized methodology. They used a blood pressure cuff while testing MVIC and again in condition 3 (active shoulder and scapular movement) to standardize the amount of LD tension to 25% of the MVIC. EMG monitoring of hip musculature was used (GMax , gluteus medius , biceps femoris , tensor fascia lata and adductor magnus ) to ensure that muscle activity did not influence or exert force on the hip joint, Prior to testing, the subject's hip was moved through 15 passive repetitions of ER/IR to loosen up the tissue and prevent tissue viscosity from altering results.
Interestingly, individual subject analysis noted variability in the resting position (RP) shift of the hip with LD tension. The authors noted that myofascial stiffness may be the cause of this variability and could potentially alter the force transmission through the TLF. This could indicate that for proper force transmission, soft tissue restrictions must be addressed by a qualified medical professional (PT, DC, ATC, LMT) prior to exercise.
This study is not without limitations. Surface EMG electrodes increase the risk of cross talk between muscles more than fine wire EMG; however, the EMG data was not a variable analyzed in the study and was only used to ensure that the hip musculature was not active, contributing to hip stiffness, during testing. EMG was also used to validate active contraction of the LD . Another limitation exists with regard to the inclusion and exclusion criteria as the authors used lack of pain, or documented injury, to ensure a healthy population. As movement impairment does not always result in pain, it is possible that some subjects had pain free lumbopelvic hip dysfunction that would influence initial resting position (RP) of the hip. This may affect net forces exerted on the hip joint; however, in this study the researchers examined the individuals natural RP and recorded deviations from that position with active or passive LD tension. This reduces the likelihood that muscle imbalance would impact the affect of LD tension on hip position. As with any study, a larger sample size assists in the global significance of the results.
Why is this study important?
This study is important because it provides "in vivo" study, of force transmission where previous research by Vleeming et al (1995) and Barker et al (2004) involved cadavers. Controversy among researchers exists in whether cadaver tissue behaves and transmits force the same as live tissue. This study offers strong evidence to support findings discovered in previous, cadaver based research. The information provided from this study offer not only supports the function of the POS but allows us to see how the position and subsequent movement of the hip can be affected by overactivity or adaptive shortening in the LD .
How does it affect practice?
There are two ways in which the evidence presented here may affect clinical practice. The first being the need to integrate the POS into a training or rehabilitation program for individuals displaying instability or inefficiency in any part of the kinetic chain. The POS provides stability throughout the entire kinetic chain, preventing the inward "collapse" (pronation) of the kinetic chain. Within a clinical setting any client with tendencies for over pronation, excessive hip internal rotation and adduction, or spinal flexion would benefit from integration and neuromuscular re-education of this subsystem. Additionally, the POS plays an integral role in sacroiliac stabilization and should be considered in anyone with low back or SIJ dysfunction. As described in the POS article : "Every time we land from a jump, get pushed in the back, step off a curb, or bend over to pick something-up – it is this subsystem, along with the optimal function of our ISS (Intrinsic Stabilization Subsystem) , that ensures optimal stability of our lumbo pelvic hip complex."
Secondly, individuals with noted muscle imbalance through the lumbo pelvic hip complex (including the SIJ) may have an imbalance in the POS that requires further investigation. The LD has a propensity for overactivity and, via the TLF, may compromise optimal motion of the SIJ and lumbopelvic hip complex, resulting in pain and dysfunction.
How does it relate to Brookbush Institute Content?
The Brookbush Institute expands the traditional definition of the POS to include the contralateral gluteus medius as it shares an attachment to the TLF via the gluteal fascia, and can assist in eccentric deceleration of hip internal rotation.
The POS is considered underactive within the Brookbush Institute's predictive models of Upper Body Dysfunction (UBD) , Lumbo Pelvic Hip Complex Dysfunction (LPHCD), Sacroiliac Joint Dysfunction (SIJD) , and Lower Leg Dysfunction (LLD) . An over active, synergistically dominant Deep Longitudinal Subsystem (DLS) is common in individuals with an under active POS as is the Anterior Oblique Subsystem (AOS) in those with LLD and UBD . However, there are times when both the POS and AOS will be both preset as under-active. When performing an overhead squat assessment, a human movement specialist should note any signs of overactivity in the DLS (knees bow-in, knees bow-out, feet turn-out or an asymmetrical weight shift), overactivity in the AOS (excessive kyphosis, spinal flexion, or hip flexion (excessive forward lean)), or under-activity in the AOS (anterior pelvic tilt, excessive lordosis). Integration of the POS into any training or rehabilitation program can be done with any combination of a "pull" activity with a leg exercise involving hip extension (eg. squat to row). If the AOS is also under-active, the Brookbush Institute recommends an AOS integration exercise (step up to press) followed by a POS integration exercise.
Although rare, it is possible to have an overactive POS . Generally, these are individuals with a history of low back pain or surgery in the lumbo pelvic hip region, who exhibit a posterior pelvic tilt during static posture and who demonstrate an inadequate forward lead during squatting.
The following videos contain exercises related to POS subsystem integration.
Squat to Row
Step Up To Pull
Static Lunge to Pull
Reverse Lunge to Pull
Squat to Sled Pull
Sources
1. Huijing, P.A. (2009) Epimuscular myofascial force transmission: a historical review and implications for new research. International Society of Biomechanics Muybridge
2. Purslow, P.P. (2010) Muscle fascia and force transmission. Journal of Bodywork and Movement Therapies 14, 411–417.
3. Smeulders, M.J., Kreulen, M. (2007) Myofascial force transmission and tendon transfer for patients suffering from spastic paresis: a review and some new observations. Journal of Electromyography Kinesiology 17, 644–656
4. Yucesoy, C.A., (2010) Epimuscular myofascial force transmission implies novel principles for muscular mechanics. Exercise and Sport Sciences Reviews 38, 128–134.
5. Vleeming, A., Pool-Goudzwaard, A.L., Stoeckart, R., Wingerden, J.P., Snijders, C.J. (1995). The posterior layer of the thoracolumbar fascia. Its function in load transfer from spine to legs. Spine 20, 753–758.
6. Barker, P.J., Briggs, C.A., Bogeski, G. (2004). Tensile transmission across the lumbar fasciae in unembalmed cadavers: effects of tension to various muscular attachments. Spine 29, 129–138.
© 2015 Brent Brookbush
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