Friday, October 22, 2010

Respiratory muscle stretch gymnastics (RMSG) a review of PUBMED from 1996-2002


Preamble:
RMSG can be called an exclusive Japanese contribution to our knowledge pool. First invented & later on further researched by Japanese researchers only. We found 6 papers by search of PUBMED with the search word “Respiratory muscle stretch gymnastics”. Abstract plus search categories found 3 full articles out of 6 mentioned journals listed in PUBMED. This article is a small review of those 6 articles.

What is RMSG?

RMSG is a group of stretching exercises sequentially performed to stretch specific muscles involved in respiration. There are 5 different muscle groups targeted in RMSG.
Respiratory Muscle Stretch Gymnastics RMSG was designed to be easy to learn and to perform at home on a daily basis, and to stretch either the inspiratory intercostal muscles during inspiration or the expiratory intercostal muscles during expiration, in attempt to reduce chest wall stiffness.

Who devised it first?

Yamanda M et al of Japan devised it first time in 1996 and they applied it on 13 COPD patients for 4 week duration whose mean FEV1 is 1.24 liters.

What was the initial report of Ymanda et al?

Out of above mentioned 13 patients 12 completed the 4 week schedule. They practiced the stretching thrice a day for 4 weeks. They claimed that Respiratory muscle stretch gymnastics is useful in pulmonary rehabilitation.

They found following changes in the spirometry based & non-spirometry based parameters after the training:

1. FRC, TLC & RV (residual capacity): Significantly decreased
2. 6- min walk distance: Increased
3. Dyspnoea after 6- min walk: Significantly decreased
4. Quality of Life (QOL): Significantly improved (Measured with the Chronic Respiratory Disease Questionnaire of Guyatt, et al)

Further studies on RMSG:

2nd published study – 1998

Onodera A et al applied a group of exercises including RMSG for chronic respiratory failure due to pulmonary emphysema. The entire group consist of pursed lip breathing, diaphragmatic breathing, respiratory muscle stretch gymnastics, and walking with synchronized breathing.

15 inpatients completed the study for 3 weeks. The dependant variables measured changed in the following way
1. VAS measured dyspnea at the end of a 6-minute walk before and after the program: Decreased significantly
2. Functional exercise capacity measured by 6-minute walking distance: Increased significantly
But maximal exercise capacity, endurance time measured by incremental treadmill test did not improve.
3. TLC & RV: Decreased significantly

This study concluded that
This combined program relieves dyspnea, increases functional exercise capacity, and decreases TLC and RV on patients with chronic respiratory failure due to pulmonary emphysema.

3rd published study – 1999

Ito M et al applied diaphragmatic breathing (DB) & RMSG separately on 16 elderly COPD patients and studied the immediate changes by them. The intervention was in the flowing order DB was performed for 10 minutes in supine position. For RMSG, 5 patterns were repeated 10 times each.

Following respiratory variables are studied after 20 minutes of gap between the end of the exercises & measurement.
1. Expiratory time: After RMSG there was a significant overall prolongation in expiratory time which was not marked after DB.
2. Minute ventilation (MV), CO2 output, respiratory gas exchange ratio, end tidal O2 fraction, end tidal CO2 fraction and tidal diaphragmatic volume: After DB there is over all decrease in the above said parameter but not seen after RMSG.
This study concluded that RMSG may have a beneficial effect on the respiratory pattern but DB may provoke post-hyperventilation hypoxemia.

4th published study – 2000

Miyahara et al studied the impact of RMSG and cycle ergometer exercise training on 18 COPD inpatients in a before-after study. The pulmonary rehabilitation program was carried out 5 days per week for 3 weeks.
Dependant variables included: PFT (Pulmonary function tests), incremental ergometer exercise test 6-min walking test, and a quality of life assessment by the Chronic Respiratory Questionnaire.

The changes are as follows:
1. VO2max (indicator of maximal exercise capacity)- No increase. But 6-min walking distance (indicator of functional exercise capacity)- increase significantly.
2. QOL improves significantly in terms of dyspnea, fatigue, and emotional state.
This study reveals a combined RMSG and cycle ergometer exercise training even for a 3-week program may be beneficial for COPD patients to increases in functional exercise capacity without an increase in maximal exercise capacity, are helpful for reducing dyspnea and improving QOL in patients with COPD.

5th published study – 2002

Minoguchi et al did a cross over trial between RMSG and inspiratory muscle training (IMT) patients with chronic obstructive pulmonary disease (COPD) to know which one is a better pulmonary rehabilitation method.
They concluded RMSG may have clinically significant benefits, which may be somewhat different from the benefits of IMT, in patients with COPD.
The compared dosages
IMT = 2 sessions of 10 minutes of training at 30% of PImax, daily × for 4 weeks and RMSG = 3 sessions of 5 RMSG patterns 4 times each, daily × for 4 weeks
* cases ware assigned in randomized order
* for cross over 4 week wash out period was given

This study found following effects of RMSG & IMT
1. PImax : RMSG has no effect on PImax but IMT increases PImax
2. Chest expansion (CE): Both IMT & RMSG show similar increases in CE.
3. FRC: Significantly decreased (by 158 ml) with RMSG, but not with IMT.
4. VC, FEV1, PEF &arterial blood gases: No significant changes.
5. 6-min walking distance: more significantly increased with RMSG than with IMT.

6th published study – 2002

Aida M et al are the first authors who tried to implement RMSG to alleviate pain in post coronary artery bypass patients. Earlier authors tried to implement RMSG mostly in COPDs.
This study is a randomized control trial with sample size 16 grouped in to 2. All of them exhibited rib cage dominant breathing after median sternotomy for coronary artery bypass grafting (CABG). One group was treated with conventional treatment and another with SMSG.

The finding ware as follows:
1. Expected decrease of spirometric measures like MIP (maximum inspiratory pressure), MEP (maximum expiratory pressure), FRC, FEV1 was small in the group treated with RMSG.
2. RMSG group had significantly reduced pain around both scapulas at discharge.
3. Overall ADL- Increased significantly in RMSG group
4. Profile of mood states (POMS)/Vigor scores, POMS/Tension-Anxiety scores: Scores at discharge for RMSG group were significantly smaller than those preoperatively.
5. 6-minutes walk distance: Significantly increased

RMSG specifically fashioned for post CABG patients approached with mid-sternotomy improves patient participation in exercise therapy and increases exercise capacity by reducing post operative pain, relieving anxiety and tension, and improving ADL.

Composition of RMSG

Five patterns have been used routinely by the clinicians. A brief description of the movements is given below. On the starting day of RMSG rehabilitation, patients learn the 5 patterns by watching a demonstration and by using a pamphlet. At home, the patients performed the 5 stretch patterns 4 times following a order from 1-5.

Pattern 1. Elevating and pulling back the shoulders
As you slowly breath in through your nose, gradually elevate and pull back both shoulders. After taking a deep breath, slowly breathe out through your mouth, relax and lower your shoulders.

Pattern 2. Stretching the upper chest
Place both hands on your upper chest. Pull back your elbows and pull down your chest while lifting your chin and inhaling a deep breathe through your nose. Expire slowly through your mouth and relax.

Pattern 3. Stretching the back muscle
Hold your hands in front of your chest. As you slowly breathe in through your nose, move your hands front wards and down, and stretch your back. After deep inspiration, slowly breathe out and resume the original position.

Pattern 4. Stretching the lower chest
Hold the ends of a towel with both hands outstretched at shoulder height. After taking a deep breath, move your arms up while breathing out slowly. After deep expiration, lower your hands and breathe normally.

Pattern 5. Elevating the elbow
Hold one hand behind your head. Take a deep breath through your nose. While slowly exhaling through your mouth, stretch your trunk by raising your elbow as high as is easily possible. Return to the original position while breathing normally. Repeat the process using the alternate hand behind the head.

Modified RMSG used by Aida M et al for post CABG pain patients:

1. Whole body relaxation
Position: Either lying down on bed or sitting on a chair.
Do: Contract muscles of face, shoulder, back, hand and feet for several seconds, then exhale deeply to relax all the muscles of the body.

2. Bending the neck forward & to both the sides
Position: Sitting on a chair.
Do:
a.Raise the shoulder for 5 seconds, then exhale deeply to relax totally.
b. While pursing the lips- exhale and bend the neck to Rt side to stretch the sternomastoid, then inhale while bringing the neck back to it’s original position. Exhale deeply to relax totally.
c. Repeat the stretch to Lt hand side.

3. Rotating the shoulder (include pectoralis major & trapezius muscles)
Position: Sitting on a chair.
Do:
Gradually rotate the shoulders & scapulas forwards few times, then exhale deeply to relax totally.

4. Stretching the shoulder girdle & tricep brachaii muscle
Position: Sitting on a chair.
Do:
Extend the arms forwards as far as possible and retain the position for 5 seconds.
While exhaling return the arms to the original position and relax totally.

5. Stretching the tricep brachaii & serratus anterior muscles
Position: Sitting on a chair.
Do:
a. While using one hand to protect the wound (of mid sternotomy used for CABG), place the other hand on the the same side shoulder bending it at elbow
b. while inhaling, slowly raise the elbow vertically to extend the serratus anterior muscle under the arm pit.
c. while exhaling deeply, return the arm to the original position and relax totally.
d. Repeat the above said procedures by changing the sides.

Limitation of above said studies:
1. Inadequate sampe size & study duration.
2. Target muscles in stretches described by Aida M seem dubious.
3. Carry over effects not discussed.

References:

1. Aida N et al; J Med Dent Sci. 2002 Dec;49(4):157-70. (Respiratory muscle stretch gymnastics in patients with post coronary artery bypass grafting pain: impact on respiratory muscle function, activity, mood and exercise capacity).
2. Minoguchi H et a; Intern Med. 2002 Oct;41(10):805-12. (Cross-over comparison between respiratory muscle stretch gymnastics and inspiratory muscle training).
3. Miyahara N et al; Acta Med Okayama. 2000 Aug;54(4):179-84. (Effects of short-term pulmonary rehabilitation on exercise capacity and quality of life in patients with chronic obstructive pulmonary disease).
4. Ito M et al; Intern Med. 1999 Feb;38(2):126-32. (Immediate effect of respiratory muscle stretch gymnastics and diaphragmatic breathing on respiratory pattern. Respiratory Muscle Conditioning Group).
5. Onodera A et al; Nihon Kokyuki Gakkai Zasshi. 1998 Aug;36(8):679-83. (Effects of a short-term pulmonary rehabilitation program on patients with chronic respiratory failure due to pulmonary emphysema).
6. Yamada M et al; Nihon Kyobu Shikkan Gakkai Zasshi. 1996 Jun;34(6):646-52. (Clinical effects of four weeks of respiratory muscle stretch gymnastics in patients with chronic obstructive pulmonary disease).




Friday, October 15, 2010

Anticipatory postural adjustment (APA) & Posture



Objective of this review: To provide the reader basic idea of the anticipatory postural adjustments with spinal disorders. Understanding this topic will lead to appreciate the kinetic chain concepts through understanding of basic postural system operation.

Posture & Poise: Posture is a term to describe shape whether good or bad. Poise is either present or absent at any moment so to describe poise as good or bad is to misunderstand its meaning. The term posture is generally accepted to relate to the dynamic relationship of the body segments in activity. Poise is a state; an ability to maintain appropriate muscle tension at all times in both movement and static positions.

A well-balanced structure is supported and mobilised by gravitational forces with minimal effort. Correct posture is considered vital for health and functioning of the internal organs and all bodily functions. A poorly balanced structure requires inappropriate muscular activity to maintain position and initiate movement. This constant state of activity leads to unnecessary contraction to hold a position and impedes functioning. For example, tight muscles around the torso restrict movement of the ribcage and prevent natural breathing.

Ideal ‘plumb-line’ correct posture can also have poor movement patterns. This is because it is not the shape that is important but how it is maintained. A 'correct posture', i.e, one that looks right, can be achieved with totally inappropriate muscular activity. Physiologist Charles Sherrington once described our systems for maintaining posture as the ‘most uncertain and untrustworthy of all’. This is not encouraging when all corrective methods for improving posture rely on the very systems that are the cause of the problem. The fact that posture can deteriorate suggests the fallibility of the controlling mechanisms.

Core muscles (muscles towards the axis of the movement) have significant impact on postural stability on which movements are superimposed by the dynamic movers that lie in a layer(s) over the core muscle(s).
Anticipatory postural adjustments are a part of any movement, hence let us understand APA.

APA- Anticipatory postural adjustment

When a task to perform a fast, focal voluntary movement coexists with a task to maintain equilibrium in the field of gravity or posture of a limb, feedforward adjustments in the activity of apparently postural muscles are used to counteract the expected perturbing forces. These reactions are generated by the central nervous system in anticipation of a perturbation, and, therefore, they have been termed "anticipatory postural adjustments" (for a review see Massion 1992).

Anticipatory adjustments have been studied in a variety of experimental procedures, including voluntary foot movements (Alekseev et al. 1979; Dietz et al. 1980), trunk movements (Oddsson and Thorstensson 1986), and arm movements in standing subjects (Belenkiy et al. 1967; Bouisset and Zattara 1981; Cordo and Nashner 1982; Friedli et al. 1984, 1988; Riach et al. 1992; Aruin and Latash 1995), as well as in tasks restricted to upper extremities that did not involve maintenance of the vertical posture (Dufosse et al. 1985; Struppler et al. 1994).

Preceding all voluntary movements, no matter how small, a pre-emptive adjustment occurs to prepare for a change of position, known as postural preparation or anticipatory postural adjustment.

We do not start to attempt the act until we have first set up the conditions we associate with the movement, even if unsuitable. You will be generally unaware of these preparatory actions and continue to apply them for every move. The affect of unsuitable preparations on movement can be likened to applying the brake on a car before driving off. Your habit of getting set to lift, run or play a shot could be reducing performance. If you are already in a state of unbalance before you move due to poor employment of muscle, the ensuing preparations for movement will be inappropriate leading to inefficient actions.

Study 1:

CNS uses the same organization of the motor command for the control of both APA (segmental control) & CPA - corrective postural adjustments (whole body posture). But APA can be non-efficient in segmental postural control. CNS use anticipatory postural muscle activities (APMA) in synergy where gravity plays a crucial role.

Chabran et al (2001) in one study concluded central nervous system (CNS) uses the same organization of the motor command for the control of both segmental and whole-body posture: APA and corrective postural adjustments (CPA), which are based on well-organized anticipatory postural muscle activities (APMA), except that APA can be non-efficient in segmental postural control.

Further this study suggests that the CNS uses a sequence of APMA: a postural muscle synergy which is predetermined as a function of the intended direction of the movements and modulates the gain towards certain muscles, in accordance with the gravitational effects, and supports reaction changes.

Study 2:

Separate control of abdominals.

A study by Hodges et al (1999) reveal that transverse abdominal (a core muscle) is separately controlled than other abdominals. APA of Tr Abd do not vary with lower limb movement but co-vary with the other abdominal muscles. Hence TrA may be controlled independently of the motor command for limb movement in contrast to the other abdominal muscles.

Study 3:

Inertia associated with APA, when the time comes, balance the inertia forces due to the movement of the mobile limb therefore counteracting the disturbance to postural equilibrium.

Bouisset et al tried to find out whether APAs are programmed or not & biomechanical consequence of APA. They found APA like others (Chabran et al) corresponds to dynamic phenomena which are centrally preprogrammed. The inertia forces associated with APA may, when the time comes, balance the inertia forces due to the movement of the mobile limb therefore counteracting the disturbance to postural equilibrium.

Hence it is suggested that posturo-kinetic programming could result from a differential sensitivity of the CNS to two biomechanical factors, a linear and a rotational one, which can characterize the perturbation associated with voluntary movement.

Study 4:

Chabran et al (2002) studied whether fatigue of postural muscles influence the coordination between segmental posture and movement or not. They found postural fatigue induced by a low-level isometric contraction has no effect on voluntary movement and requires no dramatic adaptation in postural control.

Study 5:

CNS can also suppress APA

Alexander et al (1998) found in their study in conditions of high stability demands; the central nervous system may suppress APAs as a protection against their possible destabilizing effects. These effects are more pronounced when the direction of an expected perturbation is in the plane of instability.

Study 6:

APAs are less efficient in chr. low back pain (LBA)

According to Mosley & Hodges (2006) sustained decrease in the variability of anticipatory postural adjustments (APAs) occurs when performing cued arm raises following acute, experimentally induced low back pain (LBP). Jesse et al (2009) found people with chronic LBP may be less capable of adapting their APAs to ensure postural stability during movement.

Attempts to postural improvement:

Postural correction is one of the primary interventions of many physiotherapeutic interventions.
By now we are aware that postural muscles reactions start in anticipation of movement whose inertia helps to counteract the perturbing force to equilibrium. One may see the poised & coordinated segmental posture & movements notoriously in the presence of fatigue of the postural muscles because CNS can suppress APAs.

At this point of our discussion, famous physiologist Charles Sherrington’s description our systems for maintaining posture as the ‘most uncertain and untrustworthy of all’ sounds very true. This is not encouraging when all corrective methods for improving posture rely on the very systems that are the cause of the problem.

The fact that posture can deteriorate suggests the unreliability of the controlling mechanisms. Hence to take corrective methods following problems need to be understood & addressed:

(1) functional organization of the postural system
(2) localization of postural functions in the mammalian CNS
(3) postural networks
(4) impairment of postural control caused by different deficits such as vestibular, prorioceptive, kinesthetic etc.

Core stability & posture:

Core stability is the ability of the lumbopelvic hip complex to prevent buckling and to return to equilibrium after perturbation. Although static elements (bone and soft tissue) contribute to some degree, core stability is predominantly maintained by the dynamic function of muscular elements.

Dangers of not having proper core stability:

There is a clear relationship between trunk muscle activity and lower extremity movement. Current evidence suggests that decreased core stability may predispose to injury and that appropriate training may reduce injury. Core stability can be tested using isometric, isokinetic, and isoinertial methods.

A unique approach: Core integration to lengthen myofascia to improve posture

Postural organization is controlled by the central nervous system in conjunction with the skeletal, muscular, and fascial systems. DellaGrotte et al (2008) described a neuromotor re-education intervention for static and dynamic postural misalignment. This DellaGrotte et al (2008) approach is leads to lengthening of myofascia & core integration that leads to improved postural organization.

Appropriate intervention directed for core stability & integration may not only result in decreased rates of back and lower extremity injury but also in postural improvement.

References:

1. Chabran E et al; J Electromyogr Kinesiol. 2002 Feb;12(1):67-79.
2. Chabran E et al; Exp Brain Res. 2001 Nov;141(2):133-45.
3. DellaGrotte J et al; J Bodyw Mov Ther. 2008 Jul;12(3):231-45. Epub 2008 Jul 9.
4. Bouisset et al; Journal of Biomechanics, Volume 20, Issue 8, 1987, Pages 735-742 (Biomechanical study of the programming of anticipatory postural adjustments associated with voluntary movement)
5. Alexander et al; Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control Volume 109, Issue 4, August 1998, Pages 350-359 (Anticipatory postural adjustments in conditions of postural instability )
6. Willson JD et al; J Am Acad Orthop Surg, Vol 13, No 5, September 2005, 316-325.
© 2005 the American Academy of Orthopaedic Surgeons. (Core Stability and Its Relationship to Lower Extremity Function and Injury)
7. Hodges et al; Neuroscience Letters Volume 265, Issue 2, 16 April 1999, Pages 91-94 (Transversus abdominis and the superficial abdominal muscles are controlled independently in a postural task).
8. Jesse V et al; Behav Neurosci. 2009 April; 123(2): 455–458 (People with chronic low back pain exhibit decreased variability in the timing of their anticipatory postural adjustments).
9. Deliagina TG et al; Physiol Behav. 2007 Sep 10;92(1-2):148-54. Epub 2007 May 21. (Nervous mechanisms controlling body posture).