Tag: Critical tasks

Experimenting with the Berg – 13. Component 12

Submitted by: Jeremy Nelson PT

12.0 Place Alternate foot on Step or Stool While Standing Unsupported

This component examines the capacity of the patient to perform a weight shift to unload the extremity that is going to perform the step up motion. The goal of the component is to be “able to stand independently and safely and complete 8 steps in 20 seconds”. The time part of the test provides an insight into the overall coordination power that exists in the neuromuscular system. The first task is to perform the weight shift and maintain center of gravity over the base support of the foot into a single limb pattern. The more difficult task comes next, supporting of the stance limb of the stepping up of the contralateral side.

As the lower extremity flexes at the hip and knee to place the foot on the stool, the posterior moment must be countered by the stance limb with an anterior moment. The stance hip must be strong enough to support the COG and BOS relationship in the single limb position as well a counter the posterior moment.
If the performer “needs assistance to keep from falling/unable to try” then presumably the first task was not completed. Without the initial weight shift the stepping lower extremity is unable to be unweighted to perform the motion. This is likely from inadequate control of COG to perform the weight shift or an inadequate BOS in terms of poor foot posture. Reviewing the asymmetrical stance critical tasks into the single limb critical tasks will provide the desired outcomes to measure current reality against.

Again, similar to the other Berg components time is an element to investigate and record speed as function of strength, coordination and power. In order for the extremity to successfully step up there needs to be adequate time for that to happen. The time is developed through the shifting of the body weight to the extremity that is going to be in a close kinetic chain into a single limb position.
As is described in the Component 14 discussion, the single limb position has been involved in many of the movements being examined at the end of the test. With improved single limb support, the control of the step is developed. The strength and control of the extensors and abductor’s are being examined as if there is an inadequacy in either one there will not be enough time for the patient to step up without assistance.

When the performer is “able to complete > 2 steps needs minimal assist” what type of and what degree the assistance is needed is important to identify. When using the upper extremities to assist in stabilizing the COG over the BOS to complete the weight shift points to inadequate gluteal strength or posture of the hip and knee. Assistance required to step up maybe related to the poor knee mobility.

When the performer is “able to complete 4 steps without aid with supervision” and “able to stand independently and complete 8 steps in > 20 seconds” both indicate that the critical tasks are present and the body is able to produce. The difference is a matter of speed and coordination. As the speed increases the size of the weight shift begins to narrow. The larger weight shifts in the lower scores are replaced with small shifts. However this is not to indicate that the forces that the muscles produce to counter are less important. In fact the opposite is true. As the hip strength and power increases the COG is suspended over the BOS for shorter periods of time and the return to the start position. Better control is developed and the performer is able to respond to the demands of life safer and with more confidence.

Experimenting with the Berg – 12. Component 11

Submitted by: Jeremy Nelson PT

11.0 Turn 360°.

Turning around is a difficult task to complete as it requires multiple bases of support and control of the COG to produce weight shifts in different directions. The goal of this component is to be “able to turn 360 degrees safely in 4 seconds or less”. This component includes weight shifts to establish a new base of support while maintaining the center of gravity over that new base of support and also unloading and extremity order to move that extremity. A s discussed in the Component 9 – Picking up from the floor, the Berg is not sequenced in the way that reflects increasing difficulty. As this motions includes the tasks of attaining, maintaining and controlling the COG over the single limb BOS, it would most likely be near the difficulty scale. Ideally the capacity to stand on the single limb, measured in the last component 14 would precede the turning test.

For the practicing clinician its beneficial to understand the critical tasks in each component and how they relate to other functional activities. Included in the turning is the task of stepping posteriorly to establish a new BOS and then accepting the weight shift in a posterior lateral direction. No easy task for the performer with asymmetrical strength or a hypo active inner ear.
Similar to the turning and looking over the shoulder test, the vestibular system and its contribution to control rotations in space is included. During the closing of the eyes test in symmetrical stance examined in component 5, the dependency on the vestibular and sensory system was identified. As a result the rehab professional with an abundance of caution would want to review the test result for that component before testing this component. Although the eyes remain open, the rotational component of the test could provoke a loss of balance.

When the performer “needs assistance while turning” further inquiry is helpful to determine why the assistance is required. Are the signs and symptoms of vertigo present? When does the loss of balance requiring assistance occur? To what degree is the assistance required? All questions that will help to identity the entry point into the change effort. Depending on what critical task requires the assistance, this would be the place to return to. In other words if standing in symmetrical stances requires help, then go to the critical tasks for this position and begin to explore which requires change. If the beginning goes well, and further weight shifts are impaired, go to those critical tasks for further evaluation. When the performer “needs close supervision or verbal cuing” the critical task identified as inadequate will provide the appropriate verbal cuing.

As the performer demonstrates to be “able to turn 360 degrees safely but slowly” the rehab professional will comment on the reason for the deliberate nature of the turn. Often this is due to lack of power to control the weight shifts and provide the emphasis for the quick deceleration of a weight shift and then rapid acceleration of the weight shift to the other lower extremity.

Symmetry between the sides as a goal is examined. If the performer is “able to turn 360 degrees safely one side only 4 seconds or less”, then the asymmetry is investigated. Single limb testing on each extremity will demonstrate the capacity to accept the weight shift. It may also be cause for examination of the vestibular system even if vertigo is not obvious. With a balanced system capable of performing the full turn in the time desired, the performer is well positioned to be involved in their life as they desire.

Experimenting with Berg – 15. Component 14

Submitted by: Jeremy Nelson PT

14.0 Standing On One Leg

This final component of the Berg is not its most difficult as noted earlier. In regards to the hierarchy of critical tasks, this would be around 9 or 10 if the Berg was organized based on difficulty and complexity. The single limb pattern exists in other tests, albeit for shorter periods of time than will be tested in this component. What makes the scoring on this component worthy of being the last of tests is the duration of time each score. The goal requires the performer to be “able to lift leg independently and hold > 10 seconds”. To successfully complete the goal a number of critical tasks are required. The test examines first the weight shifting found in the asymmetrical stance critical tasks and progresses into the control of the center of gravity over a small base of support. On display are the extensors and hip abductors close kinetic chain performance.

What typically undermines the capacity of the performer to attain the test position as in “unable to try or needs assist to prevent fall” is the incomplete capacity at the level of the asymmetrical stance. At this level the weight shifting is inadequate. The critical task in asymmetrical stance as during ambulation from initial contact to midstance is to complete the weight shift on a diagonal. Performers that lose their balance during this position typically perform a weight shift anterior to posterior. In an asymmetrical BOS, this will bring the COG anterior of the BOS and result in the patient losing their balance to the trailing limb side. Once the performer is able to learn the weight shift from trailing limb to the forward limb on the diagonal they are well positioned to attempt the single limb position.

To be able to lift the leg off the ground during the “tries to lift leg unable to hold 3 seconds but remains standing independently” the weight shift has occurred, however the stance lower extremity is unable to maintain the COG over the small BOS. Typically the cause is at the hip, which demonstrates instability in various planes. If the mobility of the hip is adequate to attain the knee at extension and hip at neutral, then the next task is to coordinate the hip to position the COG over the BOS. Most often the performer fails to pass 3 seconds because they have returned to the start position by falling towards midline. In other words the initial weight shift was only to the medial edge of the stance LE. The lesson here is to promote greater weight shifting to the stance LE. Focusing on enhancing the power of the hip abductors and extenders to perform in a closed kinetic chain will increase the duration of the single limb stance.

As the performer is “able to lift leg independently and hold ≥ 3 seconds” and up to “able to lift leg independently and hold 5-10 seconds” conclusions regarding the safety on different surfaces during ambulation can be made. As uneven surfaces take a longer time for the step to take place and thus require greater time in the single limb position, the performer can be considered safer as the capacity for single limb stability improves. As was described in the picking off of the floor, there can be progressions within the scoring matrix, with the changes of the BOS surface. Moving from a firm tile surface to a more compliant carpet surface provides increasing challenges regarding the establishment of the BOS and the control of the COG over the BOS. As the challenges increase and the performer progresses through this component they will find that they are better able to be involved in life as they desire.

Experimenting with the Berg – 11. Component 9

Submitted by: Jeremy Nelson PT

9.0 Pick Up Object From Floor From a Standing Position

Although 9th on the list of tests in the Berg, when examining this component for complexity it is near the top of difficulty. The goal of this component is to be “able to pick up slipper safely and easily”. How the performer completes this goal can be divided into a number of possible strategies; one that is a symmetrical stance involving a full hip hinge or squat, or an asymmetrical stance involving a modified split squat and finally as a single limb golfers lift. As a result, this component allows us to not only learn something about the current control the center of gravity in a changing base of support but also lets us know the preference for movement.

Strategies that the performer demonstrates in order to accomplish the task identifies which BOS they are most comfortable. The split squat pattern in which the person squats down to pick up the object from near the feet provides information about the asymmetrical BOS. The golfers lift in which the performer goes into a single limb to pick up the object implies a higher degree of neuromuscular development. This will be useful in organizing the change effort to come as well as knowing where on the hierarchies of critical tasks to begin and progress.

When the performer is “unable to try/needs assist to keep from losing balance or falling” there exists a profound inadequate control of the COG. This shouldn’t be a surprise at this point in the testing as the prior test components would have provided evidence the level of complexity demonstrated in this component would be unattainable. As discussed in the prior articles, this score indicates that there is work to be done in the prior supporting levels. Basic critical tasks are absent and the body segments utilized to complete these critical tasks are inadequate in more than one way.

When the performer is “Unable to pick up and needs supervision while trying” it is worth noting which base of support strategy was employed. A change effort to improve the performance in this component would most likely start in the base of support that is presented. Symmetrical base of support using the hip hinge would return to the prior functional reach critical tasks. An asymmetrical base of support could include the split squat as an entry point. And if the performer presents the golfers lift, the stance phase of ambulation would be a good entry point to consider. A problem solving approach, without considering how something is moving and seeing this simply as lack of lower extremity strength will be unlikely to succeed. There is simply to many data points that are related to consider one solution as adequate.

As the performer demonstrates “unable to pick up but reaches 2-5 cm(1-2 inches) from slipper and keeps balance independently” an adequate control of the COG over the preferred BOS can be implied. At least to the point of near the ground. The question here is whether the inability to reach the ground is due to mobility, inadequate flexibility of the body segment, or inadequate stability to attain the control required reaching the ground and return. The human brain is very good at knowing its limits and not getting caught into a position it can’t get out of. What at first looks like inadequate flexibility of tissue to attain a position could also be neurological based muscle guarding as the edges of coordinated movement are reached.

To investigate the questions, the first place to start is to return to the critical tasks of each base of support and investigate what level of flexibility and mobility exist. The seated hip hinge with reaching to the ground demonstrates adequate flexibility if all body segments perform as expected. As the base of support narrows and the complexity of the movement increases, the investigation turns to dynamic stability. The golfers lift is a complex movement that more likely indicates control of the COG to complete the task then flexibility. Further control would be demonstrated by “able to pick up slipper but needs supervision”.

By including the BOS as a data point when observing this component, further progressions or regressions can be organized. As the performer attains the goal in a symmetrical stance, move to the asymmetrical stance to complete the picking up of the object. Having attained the goal in the asymmetrical BOS, the single limb BOS is available. In this way the patient is provided a wide range of demands to learn from, resulting is greater preparation for the demands of the real world.

Experimenting with the Berg – 10. Component 8

8.0 Reaching Forward with Outstretched Arm Standing
The reaching component of the Berg is also found in its own test, the Functional Reach. It provides information about the balance. This component tests the strength of the extensors and eccentric motion of the hips in order to control the forward bending of the body at the hip joint. As the hip joint flexes and the center of gravity moves towards the anterior portion of the base support there is also a shift backwards by the core in order to maintain the base support center of gravity. If the body segments can complete these critical tasks, then the relationship of the COG and BOS is supported and the performer stays upright. As the arms reach out further, flexion at the hip occurs.Each score in the component provides valuable information regarding the state of the body segments and data to organize a successful change effort.

When the performer “loses balance while trying/requires external support” the body segments are not adequate to produce the critical task of the maintaining the COG over the BOS. This is similar to the earlier components that examined the capacity of the neuromuscular system to produce static stability. Without adequate control of static balance to begin a forward motion the performer will lose balance or attempt only with upper extremity support. Going further in the test would be likely counterproductive and possibly dangerous. Returning the upright posture of the lower extremities into extension and the pelvis into neutral maybe enough to regain the static control desired. Clearly there is work to be done at the supportive critical tasks and a regression to the basics is the best move forward.

When the performer “reaches forward but needs supervision” the body has developed through adequate posture and strength to maintain the static balance and to begin tentatively to extend the upper extremity away from the COG. As the arm extends this shifts the COM anteriorly. The body reacts by producing an extension moment on the lumbar spine as a counter force. Typically this looks like lumbar spine flexion as the performer reaches out to attempting to maintain the COG over the BOS without moving. This tug of war provides stability however ultimately limits the capacity of the body segments to support dynamic control of the COG within the BOS.

When the performer “can reach forward 5 cm (2 inches)” the observer would recognize the shift of the COG to edge of BOS by transferring body weight on to the metatarsal heads. As the reach proceeds the BOS begins to change from the full foot to the rise of the heels on to the metatarsal heads. Predictably the performer will be straining as strong gastrocsoleus is required as a counter force. The problem solving approach would be to seek to enhance the lower extremity strength to counter the forward motion, or to improve the posterior chain to again pull the body back. Instead the loss of balance indicates that the COG has left the BOS, most likely moving anterior of the BOS.

However no matter how strong the lower extremities are, completing the “can reach forward 12 cm (5 inches)” and “can reach forward confidently 25 cm (10 inches)” will not be attainable. What is required is a critical task to maintain the COG over BOS. The key is the standing hip hinge. Ironically in order to reach more forward, must be better at maintaining the COG above the BOS through the use of posterior weight shift. The hip hinge has been present before, however in the seated position and as a critical task of the sit to stand to sit components. In the standing symmetrical position utilized for this test, different body segments are contributing to the movement in different ways. Knee extension is required to perform this test and as such requires adequate biceps femoris length to attain the knee extension position. This is not enough to complete the test however, as the biceps femoris must also be flexible and strong enough to assist in controlling the anterior pelvic tilt that is part of the hip hinge movement.

Without adequate length and/or strength the biceps femoris through its origin on the ischial tuberosities will limit the anterior pelvic rotation and initiate a posterior pelvic tilt. As this occurs the lumbar spine will be forced from the extended position into relative flexion, resulting in loss of control of the posterior weight shift maintaining the COG within the BOS. The posterior weight shift to assist the forward reach will be impossible to complete, resulting in a loss of balance.

Within the context of hierarchies of critical tasks it is best to step down to the level of the squat progressions to practice the hip hinge. Using the standing hip hinge to initiate stand to sit, variations on theme can be used to enhance biceps femoris length and eccentric control. Control of the COG with this new available mobility can be practiced with the anterior weight shift in the seated position. From there the BOS is changed to symmetrical stance and the hip hinge with the posterior weight shift introduced.

Experimenting with the Berg – 8. Component 6

Submitted by: Jeremy Nelson PT

6.0 Standing Unsupported with Eyes Closed.

This component of the Berg balance test references the neurological structures that provide data to the brain. Specifically it examines the sensory structures that provide information about the body’s position in time and space. The capacity of the brain to organize around this data is also implied in the results of this test. Both provide a place for further development of a plan of care as the critical tasks for the symmetrical stance and the single limb task are the outcomes that the motor system uses the data to develop.

As a quick review, the sensory system includes the afferents of the eyes, vestibular system, the proprioceptors on the joints and the touch receptors of the skin. As the eyes are closed for this test, the visual data provided by the eyes about horizon, distance, motion is not available. As a result, the vestibular system and the sensory system are providing the data for the brain to organize balance. Although it is not a specific test of the vestibular system, this test can be a jumping off point into other test such as the CTSIB. It provides evidence for further investigation of the specific elements of the sensory system when scores indicate that balance is undermined when the eyes are closed.

A couple of lines of inquiry are supported by the data from this test. The first is in regards to the information coming from the sensory system. Is this data sufficient; are there enough nerve impulses to be a point of information for the brain to organize around, without the visual information from the eyes? Degenerative conditions such as diabetic neuropathy cause the changes that may lead to a paucity of information from the base of support skin. Due to damage of the peripheral nerves, inadequate data is available for the coordination components of the brain about what is happening at the BOS. This can sometimes be an excess of information from the pain fibers early in the condition before numbness is permanent.

Without the sensory information the brain does not know if it’s a symmetrical stance, asymmetrical stance or single limb position at the base of support. Where then to place the COG? How to organize the muscle actions when this data point is unavailable or inadequate? With the eyes closed, data that was assisting the organization is not available. However if the special testing indicates the sensory system is adequate, the next question is asked.
The next inquiry is about the brains capacity to use the information to control the COG over the symmetrical BOS. The goal is to maintain static posture in a symmetrical stance. The motor and balance sections of the brain work with the two data points of the BOS and the COG. As data in the form of nerve impulses coming from the sensory centers register the brain responds by orchestrating muscles in a coordinated fashion to support the dynamic and control. Given adequate sensory data, then the changes observed maybe a question of coordination.

The change effort is focused on the learning of the nervous system of how to use what data is available to complete the critical task. The strategy is to provide the best opportunity for learning by using the phase of learning motor related tasks. When the patient scores low and “needs help to keep from falling” there is a profound loss of sensory data from the lower extremities. The most basic level of learning that is being able to perceive something. Perception is the ability to be aware of objects, qualities, or relationships through the senses. Selecting relevant cues and relating the cues to motor acts is the domain of the balance centers of the brain. Because this is limited at this level a change effort to promote learning of the nervous system to take advantage of what little sensory data exists. Tools to increase proprioception at other joints, compensatory activities to increase the size of the base of support and core strengthening to maximize the COG control are approaches to enhance the COG BOS relationship.

When a patient is “unable to keep eyes closed 3 seconds but stays safely”, the plan of care is focused on the use of imitation as a strategy. Copying an action demonstrated by the rehab professional. This is observation and replication. Guided response through the performance of another person and/or repeating performance. Only through a great deal of trial and error can the brain learn to orchestrate the movements.

At the level of “able to stand 3 seconds” and “able to stand 10 seconds with supervision” reproduction of the critical task from instruction or memory is the focus. Guidance is withdrawn and the cueing limited. The patient is provided a variety of situations and tasks in which the critical task will be utilized. Self-correction of the failing efforts is the desired outcome for the patient to be able to set up themselves in the varying physical demands they will encounter in the world. Finally, the goal of “able to stand 10 seconds safely” confirms the patient’s ability to set up the body to complete the critical tasks. Being ready for response to through mental, physical preparation is further enhanced by practicing the critical task with eyes closed.

When using a problem solving approach, this component can seem hopeless. No treatment available will restore the damaged nerves. However as educators of movement, we can use the tools and structures developed by professional educators to enhance the learning. When viewing this component within the context of the COG and BOS relationship and thinking about the critical tasks that are required in higher levels of complexity movement, the rehab professional is better positioned to consider creating new strategies to get the job done. Instead of asking what can be done to restore sensation, instead it is what can be done to complete the critical task. In fact this is a principal of successful neurological rehabilitation. To organize around the diagnosis is to try to restore damaged tissue to impact function. To organize around the critical tasks for movement, with the principles of motor learning, a higher degree of success is likely.

Experimenting with the Berg – 7 Part 2 – Component 5

Submitted by: Jeremy Nelson PT

5.0 Transfers – Part 2

Examining the scoring matrix for this component a wide level of capacity is documented. At the lowest levels the patient “needs two people to assist or supervise to be safe” when moving from one surface to the other. This can have a number of causes and would include inadequate control of the COG to promote any level of stability. Although a higher level of function when the patient “needs one person to assist” there continues to be a lack of COG control. As discussed earlier, these scores do not provide an explanation for why what is occurring, is actually occurring. Any intervention to move towards the next level of function would include an explanation of the body segments contribution to the critical tasks of the movement, in this case inadequate.

To be “able to transfer with verbal cuing and/or supervision” the patient now demonstrates a capacity to control the COG to initiate a weight shift, although continues to require verbal instruction on how to sequence and complete each critical task. The difference between a squat transfer and a standing pivot transfer is the ability to shift the body weight to unweight one of the lower extremities to change position. Transferring requires the center of gravity be maneuvered within the base of support the patient needs to be able to shift their body weight throughout that base of support. The control of the COG to produce the weight shift likely includes critical tasks already performed in the seated and sits to stand motions. Having completed those elements, the patient would be better positioned to orchestrate the complex movements in order to change and establish a new BOS.

Why would a patient be “able to transfer safely definite need of hands”? The upper extremities are extension of the COG control. With the upper extremities supporting weight or providing more information to the brain through touch, the nervous system can better organize the weight shifting and positioning of the COG relative to the changing BOS. Again here the rehab professional is well positioned to describe the use of the upper extremities, whether for support and control of the trunk or simply for touch. Each level of upper extremity supports provides data to support the interventions planned and to document changes as a result of the intervention.

When the patient demonstrates being “able to transfer safely with minor use of hands”, the Berg component is satisfied. However the movement professional may not be as through collaboration with the patient it is learned that the transfers required by the patient to participate in life in a way that matters to the patient are not as simple as moving from one chair to the next. In life, there are varying surface heights, hand positions, motions to be made in addition to the one previously described. As the demands change, the scoring matrix can still be employed as behaviors seen and documented. And having had developed a clear record of what interventions were causative in restoring the capacity of the body to produce the critical task movements to give rise to the functional movement, the movement professional can review their notes and be well positioned to develop progressions on behalf of the patients desired level of function.

Experimenting with the Berg – 7 Part 1 – Component 5

Submitted by: Jeremy Nelson PT

5.0 transfers – Part 1

Functional outcome tools like the Berg provide a useful framework for documenting change over time. However answering the question of why that changed happened, and what were the causes of the changes observed requires the unique skills of the movement professional. The functional outcome tools provide a framework for identifying progress over time, as each scoring matrix demonstrates improvement towards a desired level of function. However those data points require further translation making explicit the relationships that give rise to the behavior being observed. Only after this reconstituting of the goal into the component parts can these elements become data points to organize a change effort around.

In the rehabilitation market today, the question “Is the intervention provided the cause of the change observed?” is the so called $50,000 question. Did the change occur as it would have any way, such as the natural progression through the inflammatory phase? Or was the change a result of another intervention, such as the elimination of pain through medication? Functional tools such as the Berg assist in identifying the desired levels of change however more is to be done by the rehabilitation specialist. The role of the rehabilitation specialist is to take that observable and measurable task and then examine and evaluate its constitute relationships. These relationships not only occur between person and the environment but include relationships between body segments and within those segments at the level of individual joints and muscles.

If the medication was the cause of the improvement, then what about the contributing body segments? Is there an acceptable level of organization to produce movement that is nondestructive? This question, motivated by the value of prevention, is a valuable use of the rehabilitation professional’s time. Are the body segments coordinated enough to provide safe movement in other typically environmental demands? Again the rehab professional has the unique tools to comment on the movement of a patient that has had the initial problem of pain reduced to provide improved function.

Consider the fifth component of the Berg, the Transfer. Transfers are basic staple of the work that is done by rehabilitation professionals. It seems so basic and simple, and yet when evaluating and working to improve transferring, the complexity can often be overwhelming. Up and to this point, the berg test has examined the COG in motion or maintained in a position relative to a static BOS. True, the sit to stand and stand to sit does include a change in BOS, however the transfer includes the change of BOS at the level of the extremities as well.

Observing a transfer from one chair to the other both the COG and BOS control is on display, the neuromuscular system ability to control the center of gravity while also organizing a changing base of support . Within a base of support that may include upper extremity support and given that it is a pivot transfer and is not necessarily stand pivot transfer what we may be observing is a use of the upper extremities to compensate for an inability of the core musculature to control the center of gravity. The rehab professional is uniquely qualified to comment on how the transfer is taking place, describing quality of movement. Just because a patient demonstrates movement consistent with a a defined score, it may not be in way that is safe over the long run.

Experimenting with the Berg – 6- Component 4

Submitted by: Jeremy Nelson PT

4.0 Standing to Sitting.

Much can be learned about the contributing body segments when observing the stand to sit motion. The body is doing more than just reversing gears from sitting to standing. Now the neuromuscular system is dealing with the acceleration of the COG caused by gravity. This is much different from the acceleration needed to overcome inertia when raising the COG above the BOS.

As a result, a different type of muscle contraction and a new level of coordination are required. The eccentric movement places a greater demand on the extensors muscles. Therefore we get to learn more about the patient’s ability to control the deceleration. Eccentric muscle contractions involve the selective deactivation of motor units and the maximization of other motor units. In this situation there is little room for error and any weakness that exists in the neuromuscular system will be magnified. Poor posture and body segments that are not contributing to the COG BOS relationship will further burden the system resulting in a loss of balance.

Consider the contribution of the thoracic spine. Commonly the thoracic spine presents in varying degrees of kyphosis. The thoracic spine although a firm structure, does contribute mobility to allow for the lumbar spine to remain stable and the cervico-thoracic junction to create a stable foundation for the highly mobile cervical spine. In addition, the mobility of the thoracic spine produces a guiding force contributing to the dynamic stability of the scapulae to support the highly mobile gleno humeral joint. Excess kyphosis of the thoracic spine impacts many of the critical tasks required to complete a smooth lowering of the COG.

First, the center of gravity must be well positioned in the symmetrical base of support. With thoracic kyphosis, immediately the body is compensating for the forward head position, resulting in a weight shift posteriorly. With this force moment already established the typical motion is to begin the stand to sit motion with a flexion of the knees, as the body attempts to keep the center of gravity within the BOS. As the knees continue to flex, the BOS begins to change as the heels lift. As a result the performer begins to lose balance anteriorly and will further compensate by a posterior weight shift to balance the feet. Overwhelmed by the force demands, the quadriceps begins to fatigue, or knees begin to hurt. A hard landing occurs with the falling backwards as the posterior moment accelerates.

The key is to change the thoracic spines capacity to support the required position to control the COG over the BOS. Manual techniques as well as therapeutic exercises can be employed to restore the thoracic spine posture. A complete extension of the thorax and pectorals is often required to return the thoracic spine and reduce or eliminate the forward head posture. Returning the cervical spine and head to their natural position also assists the vestibular system in outputting accurate data to the brain about position in time and space. With posture improved, the change effort is not completed as the goal is to promote the control of and not just capacity to.

The key here is to initiate from the hips using the hip hinge in the standing symmetrical position. The hip hinge was present in the sitting to stand motion and helped explained the different scores for the component. So is the case for the standing to sitting. The scoring includes a range from “needs assist to sit” to “sits safely with minimal use of hands”. Along the way the berg identifies the use of hands and the back of the knees to control the descent as well as the degree of control present. The use of hands and knees is a compensatory strategy to use the extremities to control the position of the COG in the BOS. Without maintaining the COG in the BOS it will be impossible to complete the lowering . This can only be done by first hip hinging to complete the tasks.

There is another way to use the hips and knees to promote the hip hinge. Cueing the patient to reach and touch their knees initiates the hip hinge. How the movement professional progresses the plan of care to improve the standing to sit movement will determine how well this motion is available to the nervous system when performing higher level tasks that will be seen in the proceeding Berg components. The inclusion of different paces of movement, supportive equipment and cueing to produce the optimal learning environment for the nervous system to learn how to control the eccentric motions will be critical in improving the patients’ involvement in life.

Experimenting with the Berg – 5. Component 3

Submitted by: Jeremy Nelson PT

Component 3.0 Sitting with Back Unsupported But Feet Supported

In the seated position, the center of gravity is closer to the base of support. The base of support is also wider than what we saw in the unsupported symmetrical standing of the previous element. As a result, it is a less complex position to maintain and work in and has a lower kinetic energy. It could then seem that this component, being easier would require less attention then more demanding postures.

This is not true, and in fact sitting capacity will be important information when working on higher levels of function. The chestnut that you must first stand before you can sit makes sense. And how one sits will influence the capacity to stand as was discussed in the first component. Although not part of the test scoring, the clinician may investigate the capacity to anterior weight shift and explore the patient’s capacity to control dynamic motion. The seated position can be an entry point into improving squat transitions and standing activity.

Within the Berg, this component time is also being measured in time. This data point is often interpreted as level of strength and endurance in the extensors must musculature. More specifically it is a measure of the efficiency of maintaining the COG over the BOS in this position. As was described in the unsupported standing, a postural assessment is helpful to examine the passive range of motions and muscle lengths to attain this position. Most important is the pelvic positioning. This will have a dominant influence on the spinal posture and further positions the COG behind the BOS when in a posterior tilt. LE posturing into excess adduction will decrease the control of the COG over the BOS and instead lead to posterior rotation moment that leads to the patient using a forward head posture strategy. In essence the patient may be trying to pull herself forward with the anterior chain resulting in poor efficiencies, likely leading to fatigue and hyperactivity of pecs, iliospoas, adductors, kyphosis and poor diaphragmatic excursion. What may at first be a lack of extensors control is more likely excess activation of the anterior chain with reciprocal inhibition of the posterior chain in sitting.

A principal in using structured motion is to always have a place to go. When the client is unable to complete a certain activity in a position, step one level down within the BOS key, or into a new BOS. For this example the difficulty is going from sitting to standing. We discussed this squat pattern based movement before. Before we began working on the critical tasks needed to accomplish the goal of standing up, the supporting critical tasks within sitting had to be completed. Within this context the choice of intervention would be to enhance the patient’s ability to complete the critical task. Within a problem solving structure the approach would be to work on leg strength to promote better sit to stand.

The critical task is a derivative of the two components of COG and BOS. Each part must do its part to support the change in COG within the changing BOS. Consider the following scenario as an exploration of therapeutic exercise as an intensification of the critical task. Establishing the base of support is the first place to start in the seated position. The seated position BOS includes the lower extremities and pelvis. Begin by positioning the feet shoulder width apart and knees and into a flexed position at approximately hundred degrees of flexion and the ankles at neutral to 5° dorsiflexion. Hip abduction to roughly 35° promotes the pelvis rotated to neutral to weight bearing on the ischial tuberosities.

A possible cause of a patient needing moderate or maximal assist is that the knees are too close together. This limits the anterior weight shift capacity as they bend forward the femur stops the anterior rotation of the pelvis. As a result the lumbar spine flexion occurs and this actually positions the core into an area of flexion instead of an area neutral extension which is the body position required to attain control of the COG. In addition it positions a center of gravity behind the base of support so it’s very important that the knees are apart from each other and that the person can spill forward in that open space between the knees. Teaching the hip hinge using the physio ball initiates the core stability that supports the hip joint do the movement. Without the core stability established lumbar spine flexion occurs and causing extension of the hip joint in the closed chain.