title: Landing error scoring system: The effect of head turned position and dual tasking

authors: Anderson, Blake

subjects: sport

abstract: Sport has many mental and physical health benefits. However, with overall participation in sport 
increasing, sport-related issues and injuries are also increasing. Anterior cruciate ligament (ACL) 
injuries are common knee injuries in athletes and the general population, often occurring through non
contact mechanisms. The Landing Error Scoring System (LESS) is a screening task used to identify 
athletes at higher risk of non-contact ACL and musculoskeletal injuries, where higher scores indicate 
poorer landing mechanics and greater risk of injury. Although the LESS is reliable, its predictive value 
is debated and it has been criticised for lacking validity in a sporting context. Previous studies have 
adapted LESS protocols in attempts to increase sport specificity, with changing head position or 
completing a dual task potentially suitable for this purpose as linked with ACL injury situations in 
sports. This thesis contains two experimental chapters. 
In the first experiment, 35 participants (22 males, 13 females) performed the LESS in two conditions 
allocated in a random order. In the control condition, participants jumped horizontally with both legs 
from a 30-cm high box to half their body height, landed with both feet, and jumped vertically as high 
as possible in one motion. In the head turned condition, participants performed the same double-leg 
jump landing movement while maintaining eye contact with an ‘X’ marked on a wall to their right, in 
line with the landing area. Participants performed three trials in each condition. Group mean LESS 
scores were significantly greater (P = 0.027) in the head turned (mean errors = 6.8 ± 1.5) than the 
control (mean errors = 6.4 ± 1.4) condition, with the mean difference of 0.4 errors being of small 
magnitude (Cohen’s d = 0.27 [0.51, 0.03]). No significant difference was found in the odds of being 
categorised at risk between conditions (P = 0.625, odds ratio = 3.00 [0.312, 28.8] based on a 5-error 
threshold. On an individual level, 28 participants were at risk in both conditions, although 13 had a 
meaningful increase in LESS score of one or more in the head turned condition. Average jump heights 
were significantly lower in the head turned condition, with the mean difference of 2.1 cm being of small 
magnitude (Cohen’s d = 0.20 [0.07,0.34]). Overall, performing the LESS with a head turned position 
appeared to increase the complexity and sport specificity of the task. Future research is required to 
determine the ability of the LESS to predict ACL injuries with a head turned condition as this aspect 
was not assessed. 
In the second experiment, an element of cognitive challenge was incorporated to the LESS in attempt 
to recreate the complex athlete-environment relationship of sports. In experiment two, 41 participants 
(20 males, 19 females, 2 others) performed the LESS in two conditions allocated in a random order. 
The control condition was the same as in the first experiment. In the tone counting condition, 
participants completed the same double-leg jump landing movement while mentally counting a random 
series of high-pitched and low-pitched tones, known as a tone counting task. Group mean LESS scores 
were not significantly different between tone counting (mean errors = 6.0 ± 1.3) and control (mean 
errors = 6.2 ± 1.5) conditions. Average jump heights were significantly lower in the tone counting than 
the control condition, with the mean difference of -4.2 cm being of small magnitude (Cohen’s d = 0.48 
[0.30, 0.66]). No significant difference was found in the odds of being categorised at risk between 
conditions (P = 1.000, odds ratio = 1.00 [0.20, 4.95]) based on a 5-error threshold. Overall, performing 
the LESS with a secondary tone counting task significantly decreased jump heights with a small effect 
size, corroborating an increased cognitive load during testing that impaired jump performance. 
However, LESS scores were not meaningfully influenced. 
Overall, introducing a head turned position to the LESS task increased LESS errors significantly, and 
introducing a tone counting task or head turned position decreased jump heights. Although future 
research is required to determine the ability of the LESS to predict ACL injuries with these dual tasking 
conditions, this Thesis demonstrates that the complexity and sport specificity of the LESS task can be 
increased by introducing dual tasking requirements.

text: Landing error scoring system: The effect of head turned position and dual tasking Sport has many mental and physical health benefits. However, with overall participation in sport 
increasing, sport-related issues and injuries are also increasing. Anterior cruciate ligament (ACL) 
injuries are common knee injuries in athletes and the general population, often occurring through non
contact mechanisms. The Landing Error Scoring System (LESS) is a screening task used to identify 
athletes at higher risk of non-contact ACL and musculoskeletal injuries, where higher scores indicate 
poorer landing mechanics and greater risk of injury. Although the LESS is reliable, its predictive value 
is debated and it has been criticised for lacking validity in a sporting context. Previous studies have 
adapted LESS protocols in attempts to increase sport specificity, with changing head position or 
completing a dual task potentially suitable for this purpose as linked with ACL injury situations in 
sports. This thesis contains two experimental chapters. 
In the first experiment, 35 participants (22 males, 13 females) performed the LESS in two conditions 
allocated in a random order. In the control condition, participants jumped horizontally with both legs 
from a 30-cm high box to half their body height, landed with both feet, and jumped vertically as high 
as possible in one motion. In the head turned condition, participants performed the same double-leg 
jump landing movement while maintaining eye contact with an ‘X’ marked on a wall to their right, in 
line with the landing area. Participants performed three trials in each condition. Group mean LESS 
scores were significantly greater (P = 0.027) in the head turned (mean errors = 6.8 ± 1.5) than the 
control (mean errors = 6.4 ± 1.4) condition, with the mean difference of 0.4 errors being of small 
magnitude (Cohen’s d = 0.27 [0.51, 0.03]). No significant difference was found in the odds of being 
categorised at risk between conditions (P = 0.625, odds ratio = 3.00 [0.312, 28.8] based on a 5-error 
threshold. On an individual level, 28 participants were at risk in both conditions, although 13 had a 
meaningful increase in LESS score of one or more in the head turned condition. Average jump heights 
were significantly lower in the head turned condition, with the mean difference of 2.1 cm being of small 
magnitude (Cohen’s d = 0.20 [0.07,0.34]). Overall, performing the LESS with a head turned position 
appeared to increase the complexity and sport specificity of the task. Future research is required to 
determine the ability of the LESS to predict ACL injuries with a head turned condition as this aspect 
was not assessed. 
In the second experiment, an element of cognitive challenge was incorporated to the LESS in attempt 
to recreate the complex athlete-environment relationship of sports. In experiment two, 41 participants 
(20 males, 19 females, 2 others) performed the LESS in two conditions allocated in a random order. 
The control condition was the same as in the first experiment. In the tone counting condition, 
participants completed the same double-leg jump landing movement while mentally counting a random 
series of high-pitched and low-pitched tones, known as a tone counting task. Group mean LESS scores 
were not significantly different between tone counting (mean errors = 6.0 ± 1.3) and control (mean 
errors = 6.2 ± 1.5) conditions. Average jump heights were significantly lower in the tone counting than 
the control condition, with the mean difference of -4.2 cm being of small magnitude (Cohen’s d = 0.48 
[0.30, 0.66]). No significant difference was found in the odds of being categorised at risk between 
conditions (P = 1.000, odds ratio = 1.00 [0.20, 4.95]) based on a 5-error threshold. Overall, performing 
the LESS with a secondary tone counting task significantly decreased jump heights with a small effect 
size, corroborating an increased cognitive load during testing that impaired jump performance. 
However, LESS scores were not meaningfully influenced. 
Overall, introducing a head turned position to the LESS task increased LESS errors significantly, and 
introducing a tone counting task or head turned position decreased jump heights. Although future 
research is required to determine the ability of the LESS to predict ACL injuries with these dual tasking 
conditions, this Thesis demonstrates that the complexity and sport specificity of the LESS task can be 
increased by introducing dual tasking requirements.

year: 2025

title: The use of the reciprocals of positive and negative inertial functions in asymptotic modelling

authors: Williams, F.W.

subjects: inverse inertia

abstract: This paper shows how the recently introduced concept of positive and negative inertial functions in asymptotic modelling may be used effectively. Noting an almost linear variation of the natural frequency over a wide range of values of the reciprocal of the inertial parameter, the results presented show that both the natural frequencies of constrained systems can be calculated accurately using only moderately large artificial inertial parameters, e.g. which are only about 10 times that of the system mass and also that values about a million times more than this do not precipitate ill-conditioning when using 16 figure computer accuracy. This helps to minimize the chances of numerical problems occurring due to the limitation of machine precision.

text: The use of the reciprocals of positive and negative inertial functions in asymptotic modelling This paper shows how the recently introduced concept of positive and negative inertial functions in asymptotic modelling may be used effectively. Noting an almost linear variation of the natural frequency over a wide range of values of the reciprocal of the inertial parameter, the results presented show that both the natural frequencies of constrained systems can be calculated accurately using only moderately large artificial inertial parameters, e.g. which are only about 10 times that of the system mass and also that values about a million times more than this do not precipitate ill-conditioning when using 16 figure computer accuracy. This helps to minimize the chances of numerical problems occurring due to the limitation of machine precision.

year: 2006

title: Te Karauna Hou: the senior Ngati Rahiri rangatira

authors: Hart, Philip

abstract: Te Karauna Hou, the principal Ngati Rahiri rangatira living at Te Aroha in 1880, had a distinguished whakapapa linking him to several hapu. Before settling permanently at Te Aroha in the 1870s he lived in several places, especially at Kaitawa, on the southern outskirts of Thames. One of the principal rangatira in Hauraki, he was loyal to the Crown during the Waikato War, and later assisted Pakeha settlement. To emphasize his mana and that of his hapu, he held big festivities at Kaitawa and at Omahu pa at Te Aroha. 
In 1871, when Ngati Haua won a (temporary) victory in the land court over the ownership of the Aroha Block, Karauna took control of it on behalf of the Marutuahu confederation, and subsequently kept Ngati Haua at bay. For a time he opposed road-making on this block, but later agreed to it, for financial reasons. Like all rangatira, he sought to maximize his ownership of as many blocks of land as possible, sometimes having his lies exposed through his contradicting his earlier evidence. He also denied receiving money for land when his denials were easily disproved. Despite leasing and selling land, selling timber and gum, and opening his land to miners, he often struggled financially.  
Karauna claimed to have found gold in Hauraki in 1852, and was willing to open his land at Thames to miners, but did not invest in any claims before the Te Aroha rush, when he attempted to extract a bonus of £1,000 from the government for opening the field. After his death in 1885, Pakeha remembered with gratitude his friendly attitude to them, but they also remembered his drunkenness, which meant he lost the respect of both Maori and Pakeha in his latter years.

text: Te Karauna Hou: the senior Ngati Rahiri rangatira Te Karauna Hou, the principal Ngati Rahiri rangatira living at Te Aroha in 1880, had a distinguished whakapapa linking him to several hapu. Before settling permanently at Te Aroha in the 1870s he lived in several places, especially at Kaitawa, on the southern outskirts of Thames. One of the principal rangatira in Hauraki, he was loyal to the Crown during the Waikato War, and later assisted Pakeha settlement. To emphasize his mana and that of his hapu, he held big festivities at Kaitawa and at Omahu pa at Te Aroha. 
In 1871, when Ngati Haua won a (temporary) victory in the land court over the ownership of the Aroha Block, Karauna took control of it on behalf of the Marutuahu confederation, and subsequently kept Ngati Haua at bay. For a time he opposed road-making on this block, but later agreed to it, for financial reasons. Like all rangatira, he sought to maximize his ownership of as many blocks of land as possible, sometimes having his lies exposed through his contradicting his earlier evidence. He also denied receiving money for land when his denials were easily disproved. Despite leasing and selling land, selling timber and gum, and opening his land to miners, he often struggled financially.  
Karauna claimed to have found gold in Hauraki in 1852, and was willing to open his land at Thames to miners, but did not invest in any claims before the Te Aroha rush, when he attempted to extract a bonus of £1,000 from the government for opening the field. After his death in 1885, Pakeha remembered with gratitude his friendly attitude to them, but they also remembered his drunkenness, which meant he lost the respect of both Maori and Pakeha in his latter years.

year: 2016