I attended physio again last night and was given this article on core stabilising which is basically the techniques that I am being taught. Very interesting stuff.
I always thought strengthing the core was acheived by situps, leg raises and back extensions etc. The current thinking however is that the deep core muscles need to be strong as they are the main stabilising muscles. Doing situps, back extension etc only really works the outer core.
Strengthening the back extensor muscles is a useful preventive approach for low-back pain. However, the current vogue in physiotherapy and fitness training is to focus on what is known as 'core stability' training, which specifically targets the smaller and deeper lumbar spine and trunk muscles. The aim of core stability training is to effectively recruit the trunk musculature and then learn to control the position of the lumbar spine during dynamic movements. This article will review the theory and research that underlies core stability training and suggest a simple exercise progression to enhance this function.
*Hodges and Richardson (1) have described the lumbar spine area as 'inherently unstable'. In practical terms, this means the lumbar spine relies for stability on the muscles that actively support the area. This 'active' support comes from four mechanisms; tension from theracolumbar fascia; intra-abdominal pressure; the paraspinal muscles; and the deep lumbar extensors (2).
The theracolumbar fascia (TLF) can provide a tensile support to the lumbar spine via deep-trunk muscle activity. The Transversus Abdominis (TA) and the Internal Oblique (IO) muscles both attach to the TLF. This fascia 'wraps' around the spine, connecting the deep trunk muscles to it. When the TA contracts it increases the tension in TLF which, in turn, transmits a compressive force to the lumbar spine, enhancing its stability. In addition the increased tension of the TLF compresses the Erector Spinae (ES) and Multifidus (MF) muscles, encouraging these to contract and resist spine flexion forces.
The intra-abdominal pressure mechanism (IAP) can provide a supportive effect for the whole lumbar area. A co-contraction of the pelvic floor, TA, IO and low back muscles increases the IAP which, in turn, exerts a tensile force on the rectus sheath. This sheath encloses the Rectus Abdominus (RA) muscle and attaches to the IO and TA, surrounding the abdomen. The tension of the rectus sheath increases the pressure within the abdomen like a pressurised balloon. This supportive 'bag of air' reduces the compression and shear forces acting on the spine. Research shows that IAP increases before and during weightlifting exercises(3) and also during running(2), lending credence to the idea that it plays a crucial role in lumbar stability.
Research also demonstrates the significance of the paraspinal and deep lumbar muscles as important stabilisers. It is likely that these muscles act with a static contraction to resist any lumbar extension and rotational forces. The paraspinal muscles - Interspinalas and Intertransversarii - provide an individual stabilising effect on their adjacent vertebrae, acting in a similar way to ligaments (4). The deep lumbar muscle - multifidus (MF) - has been shown to be active throughout a full range of motion of the lumbar spine and during movements of the lower and upper limbs (5).
From this brief explanation of the anatomy and research into the muscles of the lumbar trunk area, it is clear that the deep-trunk muscles - TA, MF, IO, paraspinal, pelvic floor - are key to the active support of the lumbar spine. The co-contraction of these muscles produces forces via the TFL and IAP mechanism which stabilise the lumbar spine, and the paraspinal and MF muscles act directly to resist the forces acting on the lumbar spine.
Further study showed that it is not just the recruitment of these deep-trunk muscles but how they are recruited that is important. Hodges and Richardson showed that the co-contraction of the TA and MF muscles occurred prior to any movement of the limbs. This suggests that these muscles anticipate dynamic forces which may act on the lumbar spine and stabilise the area prior to any movement. Hodges and Richardson also showed that the timing of coordination of these muscles was very significant, and that back injury patients were unable to recruit their TA and MF muscles early enough to stabilise the spine prior to movement. The onset of the contraction before any force can act on the lumbar spine is essential for these muscles to act as stabilisers. Furthermore Hides et al (5) found that the MF muscle showed poor recruitment in back injury patients, again showing how the recruitment of these deep trunk muscles is very important.
Interestingly, as early as the 1920s Joseph Pilates talked about developing a 'girdle of strength' by learning to recruit the deep-trunk muscles. Even without a complete knowledge of anatomy and the benefits of the latest muscle activity research, he was aware of the importance of these deep muscles and their supportive effects.
Having identified the key muscles and how they act, the next step is to establish how best to train them. As with any type of strength and conditioning training, the protocol for improving the function of the deep-trunk muscles must be specific to the task required. This specificity of training must take into account the type of contraction, the muscle fibre type and the anatomical position required.
By definition, the deep-trunk muscles act as 'stabilisers' and are not involved in producing movements, but instead use static, or isometric, contractions. Furthermore, they must act as stabilisers continuously during everyday activities as well as sport, and so require very good endurance of low-level forces. These muscles do not need to be very strong, but they must be correctly coordinated and capable of working continuously; in addition, they must hold the lumbar spine in the neutral position - the correct alignment of the pelvis that allows for the natural S-curve of the spine. These characteristics underpin the following deep-trunk muscle training programme.
The basics...
Core stability training begins with learning to co-contract the TA and MF muscles effectively, as this is key to the lumbar-support mechanism. To do this you must perform the 'abdominal hollowing' technique with the spine in the neutral position, as follows:
Start by lying on your back with knees bent. Your lumbar spine should be neither arched up nor flattened against the floor, but aligned normally with a small gap between the floor and your back. This is the 'neutral' lumbar position you should learn to achieve.
Breathe in deeply and relax all your stomach muscles. Breathe out and, as you do so, draw your lower abdomen inwards as if your belly button is going back towards the floor. Pilates teachers describe this as 'zipping up' - as if you are fastening a tight pair of jeans.
Hold the contraction for 10 seconds and stay relaxed, allowing yourself to breathe in and out as you hold the tension in your lower stomach area. Repeat 5-10 times.
Sounds easy? Well maybe, but it is absolutely vital that you perform this abdominal hollowing exercise correctly; otherwise you will not recruit the TA and MF effectively. The following tips will help to ensure your practice is correct.
Do not:
let the whole stomach tense up or your upper abdominals bulge outwards, as this means you have cheated by using the large rectus abdominus muscle (the six-pack) instead of TA;
brace your TA muscle too hard; just a gentle contraction is enough. Remember it's endurance not max strength you are trying to improve;
tilt your pelvis or flatten your back, as this means you have lost the neutral position you are trying to learn to stabilise;
hold your breath, as this means you are not relaxed. You must learn to breathe normally and maintain the co-contraction of TA and MF.
Do:
use your fingers for 'biofeedback' on either side of your lower abdomen to feel the tension in the TA muscle.
Once you have mastered the abdominal hollowing lying on your back, practise it lying on your front, four-point kneeling, sitting and standing. In each position get your lumbar spine into neutral before you perform the hollowing movement.
I always thought strengthing the core was acheived by situps, leg raises and back extensions etc. The current thinking however is that the deep core muscles need to be strong as they are the main stabilising muscles. Doing situps, back extension etc only really works the outer core.
Strengthening the back extensor muscles is a useful preventive approach for low-back pain. However, the current vogue in physiotherapy and fitness training is to focus on what is known as 'core stability' training, which specifically targets the smaller and deeper lumbar spine and trunk muscles. The aim of core stability training is to effectively recruit the trunk musculature and then learn to control the position of the lumbar spine during dynamic movements. This article will review the theory and research that underlies core stability training and suggest a simple exercise progression to enhance this function.
*Hodges and Richardson (1) have described the lumbar spine area as 'inherently unstable'. In practical terms, this means the lumbar spine relies for stability on the muscles that actively support the area. This 'active' support comes from four mechanisms; tension from theracolumbar fascia; intra-abdominal pressure; the paraspinal muscles; and the deep lumbar extensors (2).
The theracolumbar fascia (TLF) can provide a tensile support to the lumbar spine via deep-trunk muscle activity. The Transversus Abdominis (TA) and the Internal Oblique (IO) muscles both attach to the TLF. This fascia 'wraps' around the spine, connecting the deep trunk muscles to it. When the TA contracts it increases the tension in TLF which, in turn, transmits a compressive force to the lumbar spine, enhancing its stability. In addition the increased tension of the TLF compresses the Erector Spinae (ES) and Multifidus (MF) muscles, encouraging these to contract and resist spine flexion forces.
The intra-abdominal pressure mechanism (IAP) can provide a supportive effect for the whole lumbar area. A co-contraction of the pelvic floor, TA, IO and low back muscles increases the IAP which, in turn, exerts a tensile force on the rectus sheath. This sheath encloses the Rectus Abdominus (RA) muscle and attaches to the IO and TA, surrounding the abdomen. The tension of the rectus sheath increases the pressure within the abdomen like a pressurised balloon. This supportive 'bag of air' reduces the compression and shear forces acting on the spine. Research shows that IAP increases before and during weightlifting exercises(3) and also during running(2), lending credence to the idea that it plays a crucial role in lumbar stability.
Research also demonstrates the significance of the paraspinal and deep lumbar muscles as important stabilisers. It is likely that these muscles act with a static contraction to resist any lumbar extension and rotational forces. The paraspinal muscles - Interspinalas and Intertransversarii - provide an individual stabilising effect on their adjacent vertebrae, acting in a similar way to ligaments (4). The deep lumbar muscle - multifidus (MF) - has been shown to be active throughout a full range of motion of the lumbar spine and during movements of the lower and upper limbs (5).
From this brief explanation of the anatomy and research into the muscles of the lumbar trunk area, it is clear that the deep-trunk muscles - TA, MF, IO, paraspinal, pelvic floor - are key to the active support of the lumbar spine. The co-contraction of these muscles produces forces via the TFL and IAP mechanism which stabilise the lumbar spine, and the paraspinal and MF muscles act directly to resist the forces acting on the lumbar spine.
Further study showed that it is not just the recruitment of these deep-trunk muscles but how they are recruited that is important. Hodges and Richardson showed that the co-contraction of the TA and MF muscles occurred prior to any movement of the limbs. This suggests that these muscles anticipate dynamic forces which may act on the lumbar spine and stabilise the area prior to any movement. Hodges and Richardson also showed that the timing of coordination of these muscles was very significant, and that back injury patients were unable to recruit their TA and MF muscles early enough to stabilise the spine prior to movement. The onset of the contraction before any force can act on the lumbar spine is essential for these muscles to act as stabilisers. Furthermore Hides et al (5) found that the MF muscle showed poor recruitment in back injury patients, again showing how the recruitment of these deep trunk muscles is very important.
Interestingly, as early as the 1920s Joseph Pilates talked about developing a 'girdle of strength' by learning to recruit the deep-trunk muscles. Even without a complete knowledge of anatomy and the benefits of the latest muscle activity research, he was aware of the importance of these deep muscles and their supportive effects.
Having identified the key muscles and how they act, the next step is to establish how best to train them. As with any type of strength and conditioning training, the protocol for improving the function of the deep-trunk muscles must be specific to the task required. This specificity of training must take into account the type of contraction, the muscle fibre type and the anatomical position required.
By definition, the deep-trunk muscles act as 'stabilisers' and are not involved in producing movements, but instead use static, or isometric, contractions. Furthermore, they must act as stabilisers continuously during everyday activities as well as sport, and so require very good endurance of low-level forces. These muscles do not need to be very strong, but they must be correctly coordinated and capable of working continuously; in addition, they must hold the lumbar spine in the neutral position - the correct alignment of the pelvis that allows for the natural S-curve of the spine. These characteristics underpin the following deep-trunk muscle training programme.
The basics...
Core stability training begins with learning to co-contract the TA and MF muscles effectively, as this is key to the lumbar-support mechanism. To do this you must perform the 'abdominal hollowing' technique with the spine in the neutral position, as follows:
Start by lying on your back with knees bent. Your lumbar spine should be neither arched up nor flattened against the floor, but aligned normally with a small gap between the floor and your back. This is the 'neutral' lumbar position you should learn to achieve.
Breathe in deeply and relax all your stomach muscles. Breathe out and, as you do so, draw your lower abdomen inwards as if your belly button is going back towards the floor. Pilates teachers describe this as 'zipping up' - as if you are fastening a tight pair of jeans.
Hold the contraction for 10 seconds and stay relaxed, allowing yourself to breathe in and out as you hold the tension in your lower stomach area. Repeat 5-10 times.
Sounds easy? Well maybe, but it is absolutely vital that you perform this abdominal hollowing exercise correctly; otherwise you will not recruit the TA and MF effectively. The following tips will help to ensure your practice is correct.
Do not:
let the whole stomach tense up or your upper abdominals bulge outwards, as this means you have cheated by using the large rectus abdominus muscle (the six-pack) instead of TA;
brace your TA muscle too hard; just a gentle contraction is enough. Remember it's endurance not max strength you are trying to improve;
tilt your pelvis or flatten your back, as this means you have lost the neutral position you are trying to learn to stabilise;
hold your breath, as this means you are not relaxed. You must learn to breathe normally and maintain the co-contraction of TA and MF.
Do:
use your fingers for 'biofeedback' on either side of your lower abdomen to feel the tension in the TA muscle.
Once you have mastered the abdominal hollowing lying on your back, practise it lying on your front, four-point kneeling, sitting and standing. In each position get your lumbar spine into neutral before you perform the hollowing movement.
