The aim of the study was to examine test-retest reliability of the Timed Up & Go test, its ability to differentiate subjects with chronic stroke from healthy elderly subjects, and its associations with ankle plantarflexor spasticity, ankle muscle strength, gait performance, and distance walked in 6 minutes in subjects with chronic stroke. The individual measures used for the test was the Berg scale and the Barthel index.
For this study twenty one participants were used for the task (ten healthy elderly adults and eleven elderly adults with chronic stroke). The study also conducted four clinical and laboratory measures of the lower limb functions. They are spasticity of the plantarflexors, maximum isometric voluntary contraction of the ankle muscles, gait performance and a six minute walk test.
The timed up and go test required subjects were required to stand up from a chair with armrests, walk 3m, turn around, return to the chair, and sit down. The time taken to complete this task was measured in seconds with a stopwatch.
Results showed the spasticity in the ankle plantarflexors in the affected legs of subjects with stroke was significantly (P_.001) higher compared with their unaffected legs and with the mean scores of both legs in the healthy elderly subjects. For gait parameters, patients with stroke walked significantly (P_.001) slower (mean gait velocity, 48.7_22.1cm/s) than the healthy elderly subjects (mean gait velocity,125.6_23.8cm/s), with significantly (P_.001) reduced cadence (84.3_20.7 steps/min) compared with the healthy elderly subjects.
The study concluded that results show that there was a high degree of test-retest
reliability in the Timed Up & Go test scores in elderly subjects with chronic stroke. These scores were capable of detecting differences in functional mobility between healthy elderly subjects and subjects with stroke.
A study was conducted to investigate the speed-accuracy trade off in expert and novice throwers, and the movement strategies used to execute the task of throwing. It was hypothesised that the experts would maintain high accuracy throughout the range of velocities, and that the novices would show a trade in accuracy and velocity. It was also hypothesised that a change in co-ordination strategy would be expected in the form of movement patterns leading to a throw between the different groups.
The experts, in this case were male team handball players from a Norwegian second division team, and the novices had never been involved in any organised sport that required any form of throwing activity.
The data was gathered using 3D cameras, with markers placed on the body at the shoulder, hip, elbow, wrist and the ball was also tracked. Linear velocities of these points were calculated, along with time of release and total movement time. Throwing accuracy was measured by a video camera, and a ‘hit’ was recorded when the centre of the ball hit the centre of the target, otherwise, a ‘miss’ was noted.
There were several conditions, the first was where the participants were asked to throw the ball as fast as they could, in order to record maximum velocities. The second condition was also a throw at maximum velocity, but with accuracy as an afterthought. The third condition was where velocity and accuracy were equally important. In the forth condition, accuracy was the main priority with velocity as a secondary priority, and in the final condiditon the only priority was to hit the target with velocity made irrelevant.
In summary, the throwing performance of the experts was better than that of the novices in every condition, as expected, both in terms of speed and accuracy. Also, in the experts, the velocities of most of the body segments were higher than that of the novices. However, no significant differences in absolute and intersegmental timing of the movements of the body segments was found between the two groups. Also, in terms of speed-accuracy trade off both groups performed similarly. This means that when accuracy was required, acceleration and velocities were decreased, although accuracy was not actually improved.
It was thought that the novices would show more of a speed-accuracy trade off as they were thought not to have the ability to throw the ball accurately at high speeds. Therefore, it is suggested that it is the features of the required task rather than the skill level of the subject that explains the lack of a speed-accuracy trade off in handball overarm throwing.
There were no differences in timing of body segment movements between the groups. This suggests that novices and experts may use the same general coordination pattern. The analysis suggests that in a ballistic, whole body movement the accuracy was not affected by a faster execution that was likely to have been induced by more muscle activity.
Overall, it was found that the only essential difference between novice and expert throwers was the use of a wind up or counter movement, which lead on to a stronger and shorter acceleration period. By accelerating and moving faster an expert will reach the end of motion earlier. It is not proved however, that experts use the same movement range as novices. Recent data on throwing with dominant and non-dominant arms suggest that athletes use a longer movement range with the dominant arm.
The role of the Cerebellum in Learning
W. T. Thach
The aim of this study was to review previous research to see what roles the cerebellum has in learning a coordinated movement.
The cerebellum is said to learn new movements by different pathways going into the cerebellum e.g. purkinje cells. These cells were also said to be the ones producing action potentials when movement occurs.
These different pathways carry information about different situations i.e. learning a new movement. These pathways also contain a great amount of memory cells that contain the information about the new movement that has been learnt. There is also a second pathway that helps these purkinje cells learn and recognize new patterns in the information from the first pathways. In response to the new information that is inputted, new patterns of movements are then created.
Gilbert and Thach (1977) wanted to test to see if the cerebellum actually is involved when trying to learn a new co-ordination movement. To do this they tried to teach monkeys to perform different tasks using a manipulandum against constant torque loads. The main thing they were looking at were the wrist movements of the monkeys.
Within the first 12 to 100 trials the monkeys were able to adapt to the task and this was explained by Evarts (1973) as being because of the long loop functional stretch. This is when the muscle has to activated in order for movement to occur. In order for the muscle to be activated the cerebellum has to be stimulated.
One of the conclusions of the study was that once a skilled movement has been learned, it remains coded in cerebellar memory cells for a really long time.]
Coordination of the many body parts in order to attain smooth movements is usually agreed to be one of the particular roles of cerebellar control. This is often thought of as being due to a “fine-tuning” of the many movement pattern generators downstream from the cerebellum in the spinal cord, brainstem, and motor cortex (Holmes, 1939).
This study examined the sensitivity and specificity of the timed up and go test under single task versus dual task conditions for identifying elderly individuals who we prone to falling
Thirty community-dwelling older adults living in the greater Seattle area were enrolled in the study after giving informed consent. The participants were 15 older adults with no history of falls (mean age=78 years, SD = 6 range =65-85) and 15 older adults with a history of 2 or more falls in the previous six months (mean age=86.2 years, SD= 6, range 76-95)
The test was performed under 4 conditions (Timed Up and go, timed up and go with a subtraction task, timed up and go cognitive and timed up and go while carrying a full cup of water). Subjects were given verbal instructions to stand up from a chair walk 3m as quickly and as safely as possible cross a line marked on the floor, turn around, walk back and sit down.
Results showed the older adults with a history of falls were slower than the adults without a history of falling in all 4 conditions. Analysis showed that the difference in time is due to their balance status.
Results suggested that adults who take longer than 14 seconds have a higher risk of falling. The cut off value of 14 seconds is different from that of Podsiadlo and Richardson, who found that a cut off value of greater than 30 seconds was best for predicting functional dependence among older adults
1. Assessment sessions consisted of both judgement trials (at both 90° and 180°) and movement trials (moving at 0°, 90°, and 180°). There was no feedback.
2. Training consisted only of judgement trials at 90° with feedback.
The Experimental group did three assessment sessions and up to 14 training sessions. The Control group did three sessions of movement trials, with no training or feedback.